Primavera De Filippi

Morshed Mannan

Wessel Reijers

The Alegality of Blockchain Technology

Keywords: blockchain technology, decentralized autonomous organisations, alegality, legal theory, legal philosophy, blockchain governance, regulatory sandbox

Similar to the early days of the Internet, today, the effectiveness and applicability of legal regulations are being challenged by the advent of blockchain technology. Yet, unlike the Internet, which has evolved into an increasingly centralised system that was largely brought within the reach of the law, blockchain technology still resists regulation and is thus described by some as being " alegal ", i.e., situated beyond the boundaries of existing legal orders, and therefore challenging them. This article investigates whether blockchain technology can indeed be qualified as alegal, and the extent to which such technology can be brought back within the boundaries of a legal order by means of targeted policies. First, the article explores the features of blockchain-based systems which make them hard to regulate, mainly due to their approach to disintermediation. Second, drawing from the notion of alegality in legal philosophy, the article analyses how blockchain technology enables acts that transgress the temporal, spatial, material and subjective boundaries of the law, thereby introducing the notion of " alegality by design " -as the design of a technological artefact can provide affordances for alegality. Third, the article discusses how the law could respond to the alegality of blockchain technology through innovative policies encouraging the use of regulatory sandboxes to test for the 'functional equivalence' and 'regulatory equivalence' of the practises and processes implemented by blockchain initiatives.

Introduction

Blockchain technology poses challenges to policy makers and regulators, mostly due to the decentralised nature of public, permissionless blockchain-based networks. The operations of these networks are determined by a computer protocol enforced by a decentralised network of nodes, responsible for processing transactions and recording them into the blockchain [START_REF] Nakamoto | Bitcoin: a peer-to-peer electronic cash system[END_REF]. To the extent that all network nodes follow the same protocol, no single party can unilaterally dictate or influence the operations of the network. Moreover, because of its decentralised nature, even if one or more of these nodes were forced to shut down the network (due to a technical glitch or regulatory constraint), it could continue to operate as long as there remains at least one running node [START_REF] Swan | Blockchain: Blueprint for a new economy[END_REF]. Public blockchains are also essentially pseudonymous, in the sense that anyone can join and operate the network without having to disclose their real identity [START_REF] Lai | Blockchain-from public to private[END_REF]. They only need a public-private key pair to generate a public address and interact with the network. It can, therefore, be challenging for governments or other centralised authorities to impose their sovereignty over these blockchain-based networks, due to their limited ability to identify network actors or control the network's operations. On the whole, blockchain-based systems exhibit a set of distinctive characteristics -namely related to (1) decentralisation, (2) transnationality, (3) tamper-resistance, (4) pseudonymity, (5) lack of coercion, (6) trustlessness, and (7) operational autonomy-which, combined, make them particularly resistant to legal regulation [START_REF] De Filippi | Blockchain and the law: The rule of code[END_REF].

Because of these distinctive characteristics, blockchain technologies can be said to challenge the boundaries of the legal order(s) in which they operate. This means, amongst other things, that these legal orders are unable to see certain activities conducted through blockchain-based networks, or simply that they lack the codes to understand or even just describe them. Influential proponents of blockchain technology such as Gavin [START_REF] Wood | Alegality: Systems that can't care. CoinScrum and Proof of Work Media: Tools for the Future[END_REF] have asserted that blockchain technologies are potentially "alegal", to the extent that they support and enable activities which are neither legal or illegal, nor extra-legal. However, whatever the accuracy of this claim might be, it has never been assessed within the broader theoretical framework of alegality in legal philosophy. This paper will critically connect the different discourses of alegality, using the characterisation of alegality in legal philosophy to assess the claim to alegality of blockchain technologies. It first investigates the extent to which blockchain technology can indeed be considered as alegal, to subsequently explore new paths for governmental authorities to regulate blockchain technology, despite its alegal characteristics.

The contributions of this article are threefold. First, the article contributes to the existing academic discourse on governance and regulation by the infrastructure, while exploring the notion of blockchain as a regulatory technology that operates within its own technical framework and independently of existing regulatory frameworks. By linking this discourse with the relevant academic literature on alegality, the article investigates the reasons why blockchain technologies can be said to operate outside of the purview of the law, and how existing legal orders could potentially respond to that challenge. Second, the article also contributes to the literature on alegality by introducing the notion of alegality by design . Thus far, the academic discourse on alegality has mainly focused on alegal acts as speech acts performed by human beings, with little attention paid to the politics of technological artefacts themselves [START_REF] Winner | Do Artifacts Have Politics?[END_REF]. Indeed, if the potential for alegality is embedded into the technological architectures through which people interact, the technological design of a blockchain-based system can be regarded as providing the affordances for an alegal act. Third, assessing the alegal nature of blockchain technology makes it possible to suggest specific policy recommendations on how blockchain technology may be regulated. In this regard, we propose expanding the use of regulatory sandboxes.

Section one of the article outlines the concept of alegality and the different ways in which this multifaceted idea has been defined and understood both by the academic literature and by practitioners in the blockchain space. Section two illustrates the alleged alegal nature of blockchain technologies through a variety of examples, including the publication of the Bitcoin whitepaper, TheDAO attack, the pseudonymity inherent in public blockchain networks, and the characteristics of smart contracts. Section three shows that the claim that blockchain technologies can promote alegal activities does not mean that these activities can never be regulated or brought within the ambit of the law. It concludes by offering a policy path to address the alegal characteristics of blockchain, through the use of regulatory sandboxes to test for the 'functional equivalence' and 'regulatory equivalence' of the practises and processes implemented by blockchain technology.

Defining Alegality

The distinctive features of blockchain-based systems have led key stakeholders in the blockchain space to describe public, permissionless blockchains as "alegal" systems. This term was introduced in the blockchain space by Ethereum co-founder Gavin [START_REF] Wood | Alegality: Systems that can't care. CoinScrum and Proof of Work Media: Tools for the Future[END_REF] to advance the idea that decentralised blockchain-based systems are similar to forces of nature [START_REF] Lustig | Intersecting Imaginaries: Visions of Decentralized Autonomous Systems[END_REF]: they are neither legal nor illegal, they merely subsist outside of the legal realm. The claim made by these commentators is not that blockchain-based platforms are difficult to regulate (as the argument was with regard to the Internet in its early days), but rather that they should be regarded as neither an object nor a subject of law [START_REF] Atzori | Blockchain technology and decentralized governance: Is the state still necessary?[END_REF]. Indeed, to the extent that they do not depend on a single centrally-controlled web interface, and no physical assets are involved in any of the associated transactions, these platforms can be designed to largely ignore the coercion of the law [START_REF] Miller | Continuing Challenges to International Law and Order from Evolving Technologies such as Blockchain[END_REF]: not only do they not depend on the coercive force of the State to enforce transactions and commitments, they are also indifferent about the legal context in which transactions and commitments occur.

To explore whether blockchain-based systems can indeed be claimed to be alegal, we first examine what meanings have thus far been ascribed to the concept of alegality, with reference to more general examples. Alegality provides a conceptual basis to perceive and understand all that exists beyond the law, all that lies beyond the distinction of legality and illegality created by the state's legal apparatus (i.e., the legislature, courts and tribunals). In order words, alegality encompasses all the acts that, at a given moment, exceed the intelligibility of the law and cannot be reduced to the legal/illegal binary. They present a particular form of distinctiveness-or 'strangeness' (Lindahl 2013b, 730)-that makes them difficult to identify or categorise within the scope of legal orders. As such, alegality can broadly be understood as the " capacity to be neither legal or illegal, the ability to exist and act in the interstices, or perhaps beyond or outside, the dominant modes of [...]legal production " (Hamzić 2017, 191).

It has to be noted that, although we connect the claims to alegality made by blockchain proponents with the broader academic literature on alegality, we do not intend to establish a basic similarity between these two different usages of the term. Indeed, as we shall see, the definition of alegality proposed by blockchain advocates and that provided by academic scholars lie far apart. Yet, we argue that, even if they think differently about the origin of this phenomenon, both share a common intuition concerning the emergence of specific acts that fall beyond the boundaries of the legal order, and might thus require it to evolve in order to accommodate these acts. While Lindahl identifies alegal acts as those that do not properly fit into the established legal/illegal categories of a legal order because of their 'strangeness' (Lindhal 2013b), [START_REF] Wood | Alegality: Systems that can't care. CoinScrum and Proof of Work Media: Tools for the Future[END_REF] seems to assume that technological systems (e.g., those powered by blockchain technology) can also present alegal challenges because of their strangeness or 'inhumanity' (Hui 2019).

A widely accepted definition of a legal order is as an "aggregate of […] general and individual norms that govern human behavior" (Kelsen 1982, 64), which is typically, but not always, created through legislative acts. These legislative acts are underwritten by the coercive powers and apparatus of the state [START_REF] Pistor | The Code of Capital: How the Law Creates Wealth and Inequality[END_REF]. They are the basis for public and private law, which also underpin transactional ordering through the establishment of property rights and binding commitments between private parties. Hans Lindahl, one of the main theorists on the topic of alegality, broadens this definition whilst contemplating emergent global legal orders. His definition is particularly relevant when considering blockchain technologies. He contends that legal orders are a particular type of collective action: "institutionalised and authoritatively mediated collective action" (Lindahl 2018, 60) [emphasis added]. By this, he means that a legal order relies on specific authorities that regulate collective action on behalf of all participants through the articulation, monitoring and upholding of (capaciously defined) rules. Moreover, unlike some other forms of collective action, a legal order can create impersonal or anonymous relations between participants and with the authorities in charge of defining and applying the rules. This means that, for there to be a legal order, most of the participants have to agree to be subject to a common set of rules (what Lindahl more capaciously calls a 'default setting') and accept the role of institutions as authorities responsible for the institutionalised mediation and application of these rules. This requires accepting the existence and validity of these common rules as a consequence of the authority held by certain offices (e.g., office of the US President), regardless of the particular individual that holds that office at any given point in time (Lindahl 2018, 54-59;Shapiro 2014, 286). Specifically, Lindahl (2013a), argues that all legal orders determine who ought to do what, where and when , through the setting of boundaries-both tangible and intangible-which stipulate what is legal and what is illegal. These dimensions correspond to the "spheres of validity" of the norms in a legal order (Lindahl 2018, 51). As such, legal orders are always and necessarily bounded: not only are they circumscribed by the set of legal provisions that constitute the legal system, each of these provisions also exhibit a particular set of boundaries that establish a distinction between the legal and the illegal (Lindahl 2011, 35). Lindahl categorises these boundaries into four broad categories: (1) temporal , (2) spatial , (3) material , and (4) subjective boundaries, discussed in more detail below. According to Lindahl, an alegal act is one that fundamentally questions or challenges these boundaries, thereby revealing the boundary as a limit and potentially triggering a change of the legal order (Lindahl 2009, 57;Lindahl 2018, 65). Importantly, the opening towards another possible form of legality through the commission of alegal acts is central in distinguishing alegality from illegality-which is not concerned with alternative legalities, but rather with reinforcing existing legal boundaries. We delineate below the four types of boundaries identified by Lindahl, which we interpret in light of the existing literature on alegality.

First, legal orders are temporally bounded: laws are created at a particular point in time, and in principle should not be retroactively applied to previous events. In doing so, laws provide an orientation of when something is permitted or ought to be done-and when it is not (Lindahl 2013a, 20-21). Most importantly, laws are stipulated based on past acts and knowledge about past behaviours; they cannot cover all the unprecedented acts and unknown unknowns that lie in the future. Thus, paradigmatic examples of alegal acts that transgress the temporal boundaries of a legal order are those acts that initiate something new, those that aim to establish a new form of legality that is incommensurable with the existing one. The commission of such an alegal act would thereby usher in a novel way to structure the sequence of when and how something can be appropriately done. These acts can range from foundational acts seeking to constitute a new legal order when the distinction between legal and illegal is formed (e.g., the declaration of an independent state by revolutionaries) to official acts in which the sovereign decides on the existence of a state of exception and suspends some of the established distinctions between legality and illegality for a limited period of time (e.g., suspension of rights of assembly during a national emergency).

Second, legal orders are spatially bounded: they operate within particular territories in which rules of legality and illegality apply-even though these territories may sometimes overlap. While these boundaries may be the territorial boundaries of a state, they also include novel spatial configurations-such as multinational corporations with operations spanning across multiple jurisdictions-whose internal legal order transcends state territorial boundaries (Lindahl 2018, 143-144). In Lindahl's view, even a transnational space like cyberspace is ultimately affected by the spatial boundaries of the law. He uses the example of the B2C e-commerce platform eBay to argue that even if user agreements and online dispute resolution mechanisms are used to decouple national law from private 'eBay law', at least two physical places are interconnected into a spatial unity for the purpose of payment and goods shipment: the seller-place and the buyer-place (Lindahl 2018, 152). Alegal acts that transgress the spatial boundaries of an established legal system are those that put into question the physical places where certain actions are permitted or ought to take place. The border crossing of immigrants is an example of such an act, as each crossing questions the distinction between legality and illegality drawn by the polity which immigrants are trying to enter. According to Lindahl, the entry of impoverished economic migrants into the EU and their employment in the internal market underlines the possibility of an alternate legality -one where the 'illegal' participation of these migrants in the internal market would be possibly 'legal', and the restrictions on a global free movement of labour would be regarded as 'illegal' (Lindahl 2008, 126). 1Third, legal orders are materially bounded: they are expressed through definite configurations of rights and obligations which, combined, determine the variety and content of the acts that can be done at any point in time and place (Lindahl 2013a, 21). Alegal acts can transgress the material boundaries of a legal order by doing things that have not been (expressly) authorised or permitted, with a view to reconfigure that specific set of rights and obligations that stipulates what ought to be done in a particular legal order. An example is that of peoples' tribunals which are formed to deliberate and rule on a particular dispute (e.g., Permanent Peoples' Tribunal on Myanmar) that emerged as a response to the limitations of the international criminal justice system in investigating international crimes and alleged perpetrators. These tribunals take on a quasi-institutional form and adopt languages, processes and symbols of State tribunals, but rely on alternative conceptions of justice (e.g., reconciliation) and differing modes of court procedure (e.g., more relaxed conceptions of legal standing), and are not supported nor expressly recognized by established legal orders. Their decisions have no binding force, but they are instead framed as a response to institutional failure and thereby exemplify and promote an alternative, better system. For Hughes (2019, 473-475), it is these very characteristics that make these people's tribunal not illegal, but alegal.

Fourth, legal orders exhibit subjective boundaries that determine whose acts are to be either legally protected or sanctioned. Most legal orders implement different tiers of subjecthood, in which one's legal status (conferred by, e.g., citizenship) allows for varying degrees of rights and protections. Asylum seekers or prisoners are archetypal examples of legal subjects whose status may entitle them to some rights and protections, but exclude them from others (e.g., voting in national elections).

Alegal acts that transgress subjective boundaries are generally those where a subject challenges the prohibitions on their conduct that arise due to their particular status, with the intention of reconstituting the boundaries of this prohibition elsewhere, such as, for instance, slaves who participated in the abolitionist movement in the U.S. In extreme cases, legal orders may also cast subjects outside of their boundaries even with no geographical displacement, for instance in the case of the Roman Homo Sacer [START_REF] Agamben | Homo Sacer: Sovereign Power and Bare Life[END_REF], the condemned individual who is placed beyond the law through a legal verdict, no longer benefiting from legal protection and thus becoming legitimately killable by anyone.

Alegal acts may transgress multiple boundaries at the same time. Inner-city slums in countries like Brazil and Pakistan have been described as alegal spaces (Hamzić, 2017, p. 199). While not being entirely free from the state apparatus, residents in these localities resist imposition of state law and largely self-regulate, thereby transgressing spatial boundaries (i.e., of a city's legal order), material boundaries (i.e., enabling or restraining what residents can do, which do not exist elsewhere) and subjective boundaries (i.e., enabling or restraining acts by virtue of their position as poor citizens and migrants). In these contexts, as de Sousa Santos (1977, p. 5) argues, the incapacity of the state legal system to affect or effectively regulate these activities leads to the creation of an "internal legality, parallel to-and sometimes conflicting with-state legality, a kind of popular justice". Importantly, alegality should not be confused with extra-legality. Extra-legality refers to acts that are explicitly exempted from legal scrutiny by a legal order, and hence-paradoxically-fall within its boundaries. An example would be the immunities from criminal prosecution granted to diplomats when performing official acts in legitimate exercise of their functions (Shi 2021, 46). Another example is the corporate charter given to corporations in the 18th century that granted them with "legal exemptions to benefit public welfare" (Barkan 2013, 16) that protected them from acts of the sovereign. In contrast, alegality exists at the interstices of the law and extends beyond it, with its "infinite possibilities'' continuing to exist even after the boundary between legal and illegal has been redrawn by a sovereign power (Shimabuku 2019, 1-2).

The transgressive potential of alegal acts remains latent, but ever-present. When these acts manifest, they have the potential to affect or reshape the existing boundaries of an established legal order. In Lindahl's terms, at the juncture where these transgressive behaviours and actions manifest, the boundaries that unite the legal order can be experienced as limits to what lies beyond (2013a, 41). In his view, these limits, which include and integrate certain ought-places (i.e., who ought to do what, where and when) and exclude others, is a fundamental feature of any legal order (Lindahl 2019, 5). It is often in response to alegal acts that these boundaries may be reordered by a legislative or judicial power so as to reframe the boundaries of (il)legality and the "limit between collective self and other-than-self" (Lindahl 2019, 18). However, there are some situations in which alegal acts, although transgressive to the legal order, cannot easily be resolved through a legal reform. In such cases, the boundaries of the legal order can be regarded as fault-lines , whereby the normative claims raised by the alegal acts cannot be addressed by the legal system, without putting into jeopardy the very identity of that system (Lindahl, 2013a, pp. 3-4, 165;Lindahl 2019, 22). If a legal order is viewed as a " closed , self-referring and autopoietic system that creates, amends, interprets and justifies itself through itself" (Kedar 2006, 101) [emphasis added], fault-lines reveal the frailties of this view. In addressing fault-lines , a justification also has to be sought from beyond the seemingly closed, self-referring legal order (e.g., in politics) to decide on whether its identity should be placed in jeopardy or not. But, as the normative point of the existing legal order is threatened and the alegal acts are irreducible to this legal order, an opening is created to a different normative conceptualisation of how legal and illegal is distinguished (Schaap 2009, 4). Tuori adds that alegal challenges can also be presented by parallel legal orders, such as indigenous legal systems and state territorial legal systems, with competing normative claims about how legal/illegal should be distinguished (Tuori 2016, 134).

In view of the above, three types of alegal acts can be distinguished. First, there are common, everyday acts that are situated beyond the boundaries of the law in a practical sense. These are all these acts that are not intended to be covered by liberal legal systems, such as the act of thinking. Second, there are acts that are not yet intelligible to the legal order but that can be. This includes both acts that were potentially meant to be covered by the law, but weren't properly encompassed, as well as those that were deliberately excluded, but have now become relevant for legal regulation. This could be due to a shift in circumstances or the advent of new technologies. This is the case, for instance, of all these acts enabled by the advent of Internet and digital technologies, which required a legal reform in order to restore the previous equilibrium of the law (e.g., extending copyright law to fight online piracy), or which triggered the establishment of new legal rules in order to cover a new usage of technology (e.g., autonomous vehicles). Third, there are specific alegal acts that could possibly be brought within the boundaries of the legal order, although doing so would be challenging to the extent that it would require a significant reform of the legal system as a whole, in that the mere absorption of these acts within the legal system would potentially create an incongruence or inconsistency with the other provisions of the legal order. These acts enable us to identify the fault-lines of a legal system, and are of particular interest to us in our analysis of the alegality of blockchain technology.

In what follows, we expand on Lindahl's conceptualisation of alegal acts as political acts, in order to investigate how blockchain technology, by virtue of its technological design , could be said to generate specific affordances for alegal action. The reasons to expand Lindahl's conception of alegality are twofold: one the one hand, Lindahl omits to discuss the political stance of technological artefacts, who could be intentionally designed to support or facilitate alegal acts; on the other hand, Lindahl exclude from the notion of political acts the possibility of a technologically mediated political act, thereby failing to acknowledge the alegal affordances that blockchain technology can have.

First, even though Lindahl (2013aLindahl ( , 2013b[START_REF] Lindahl | Authority and the Globalisation of Inclusion and Exclusion[END_REF] engages with discussion of (a)legality in cyberspace, he does not thematise the role of technology as such. He draws extensively from systems theory to set up his account of cyberlaw, but in doing so he adopts an instrumental understanding of technology linked to cybernetics. That is, Lindahl regards technology as a neutral instrument in the unfolding of collective action that leads to an institutionalisation of the legal order. This comes to the fore in Lindahl's discussion of a confrontation of claims mediated by cyberspace, between people like [START_REF] Barlow | A Declaration of the Independence of Cyberspace[END_REF] who proclaims the independence of the cyberspace as a separate legal order, and the Somali man who attacked the Danish cartoonist Westegaard in his home for drawing a provocative religious cartoon and publishing it online, who challenges the idea that state law do not have the ability to reach the cyberspace (Lindahl 2013b). In his account, the technological medium through which these claims are made seems of almost no consequence; the same argument would hold if controversial cartoons would not have been published online but rather in a paper magazine. Digital mediation is just regarded as a new way by which people can relate to other people and things in the world (Lindahl 2018, 150-151); it does not transform these relations. Yet, philosophers of technology have convincingly argued that technologies enshrine political values [START_REF] Winner | Do Artifacts Have Politics?[END_REF]) and that the technical medium through which actions are conducted inform those very actions [START_REF] Latour | On Technical Mediation -Philosophy, Sociology, Genealogy[END_REF]. Hence, the possibilities afforded by Internet technologies enable new technological practises that might supplant the law with its own legal order (hence, the argument that "code is law"), but at the same time might trigger a legal reform to accommodate these new practises (e.g., a new understanding of the 'right to be forgotten'). Similarly, the technological design of blockchain technology-as a decentralised, transnational and autonomous infrastructure-enables the emergence of a new autonomous legal order (so-called lex cryptographica ) which can also present alegal challenges to the extent that it might destabilise the boundaries of existing legal orders. We refer to this as alegality by design.

Second, the notion of technologically mediated alegal action is largely omitted by Lindahl because alegality, in his view, exclusively refers to the comportment of an agent who engages in political action. Lindahl builds his conceptualisation of alegal action upon Arendt's notion of political action, which she describes as "acting and speaking in concert [...] in the space of appearance" [START_REF] Arendt | The Human Condition[END_REF], 181, Lindahl 2006). Specifically, in [START_REF] Arendt | The Human Condition[END_REF], we do not readily find the possibility of technological practice as political action, since political action, for Arendt, is never an act of making or fabricating, but only one of direct communication.2 However, if-as we argue above-artefacts "have" politics [START_REF] Winner | Do Artifacts Have Politics?[END_REF], it becomes necessary to expand the notion of political action (as envisioned by Lindhal and Arendt) to also encompass a subset of technological mediated actions. As such, alegality can also be enacted through specific practises of design, use, and appropriation of technologies. We argue that such an understanding of political action is necessary in order to account for the distinctive characteristics of blockchain technology, and the affordances that they provide to alegal acts. Accordingly, the design, use, and appropriation of these technologies can be regarded as political activities in and of themselves, which can-in specific circumstances-also qualify as alegal acts.

Alegality of Blockchain Technology

We can investigate the alegality of blockchain-based systems by considering the extent to which they enable acts that transgress the boundaries of the legal orders in which they operate. We analyse in particular the manner in which blockchain technology may reveal the fault-lines of established legal orders. This will be shown by considering how extending the boundaries of the law in order to bring the alegal acts enacted by blockchain technology back within the scope of the traditional legal/illegal dichotomy could potentially disrupt the legal system as a whole, by introducing a series of incompatibilities or inconsistencies within the legal order.

With the publication of the Bitcoin whitepaper, Satoshi Nakamoto carried on a foundational act that brought into being a new monetary system that did not exist before, and could therefore not be encompassed by the law. The deployment of Bitcoin can be seen as a transgressive act within established financial legal orders as it questions the core role of trusted financial intermediaries with an alternative peer-to-peer network that can function as an effective monetary system, and which relies on confidence rather than trust (De Filippi, Mannan & Reijers 2020). As such, Bitcoin challenges the distinction between legality and illegality in the context of monetary and financial regulations, by creating a new monetary system that could potentially undermine the exclusive roles of legally established financial institutions (De Filippi & Mauro 2014) most notably with regard to the issuance and recognition of money as legal tender. If central banks have a legal monopoly over the production and supply of legal tender, the publication of the Bitcoin whitepaper has the potential of challenging this monopoly. It presents an opening to "another legality" (Lindahl 2009, 60), one where Bitcoin could potentially be recognized as legal tender by a sovereign nation, even if it is not issued by any central bank. As such, the publication of the Bitcoin whitepaper reveals a temporal fault-line in the legal order: could Bitcoin be recognized as legal tender when it is not backed or issued by any sovereign authority? In the Western political imagination, the issuance of coinage has long been seen to be the prerogative of the sovereign, second only to the monopoly on legitimate violence and the making of laws (Bodin 1992, 78;[START_REF] Woodhouse | Who Owns the Money?" Currency, Property, and Popular Sovereignty in Nicole Oresme's De moneta[END_REF]. Recognition of Bitcoin as legal tender would require the legal order to reconstitute its boundaries to forego the expectation that legal tender can only be issued or backed by sovereign states. Despite the associated administrative, legal and political implications that such an act might entail, such a reconstitution has recently occured in El Salvador (Associated Press 2021)-the first country to recognize Bitcoin as legal tender.

The advent of Bitcoin, and blockchain technology more generally, also resulted in the development of new applications that can more easily escape the force of existing regulations (De Filippi 2014). These applications leverage the pseudonymity of Bitcoin or other cryptocurrencies to facilitate money laundering, create decentralised marketplaces for illicit goods or services [START_REF] Trautman | Virtual currencies; Bitcoin & what now after Liberty Reserve, Silk Road, and Mt. Gox?[END_REF], and provide a new payout mechanism for cyberattacks. The tamper-resistant features of blockchain technology can be abused to permanently record questionable content and preclude the exercise of specific rights that require the deletion of content (De Filippi 2016), such as the right to be forgotten (Finck 2019). These applications are strictly speaking illegal , in that they are expressly sanctionable by a particular body of law. Yet, the fact that they are illegal in a particular domain, does not prevent them from also being alegal in another domain, to the extent that they can trigger the boundaries or reveal the fault-lines of a particular body of law.

These dynamics are particularly visible in the context of property law. Traditional property rights are defined by the law, and can therefore also be taken away by the law. Hence, someone who stole or fraudulently acquired possession of a particular piece of property could be found to lack legal ownership of the property and have it frozen or seized by law enforcement authorities. The advent of blockchain technology, however, enabled the emergence of new "crypto-assets"-like cryptocurrencies or blockchain tokens-that do not follow the same rules. Blockchain technologies rely on a new technologically-driven paradigm for ownership that does not necessarily map onto legal ownership: anyone holding the private key associated with a particular Bitcoin wallet will be technically the owner of any Bitcoins within that wallet, even if he or she would not qualify as the legal owner thereof.

Interim injunctions and worldwide freezing orders may be imposed on intermediaries like cryptocurrency exchanges and crypto-custodians in an effort to enforce legal ownership. 3 Yet, for all those who do not rely on third-party intermediary services, no enforcement authority will have the ability to unilaterally seize their Bitcoins, even if they were found guilty to have illegitimately acquired them. Moreover, the pseudonymity and global distribution of people making transactions on a blockchain makes it particularly difficult for regulators to identify the actors who should be subject to legal orders and sanctions in the event of a transaction that is deemed to be illegal [START_REF] Dimitropoulos | The Law of Blockchain[END_REF](Dimitropoulos, , 1182)). This might, ultimately, create a discrepancy between the legal order and the technical order of blockchain-based applications, whose alternative regime of property rights (involving both pseudonymous parties and algorithmical entities or smart contracts) can thus be said to challenge both the material and subjective boundaries of the law. The alegality of this alternative property regime has been partially addressed by states' legal order through the Know Your Customer (KYC) requirements imposed on many cryptocurrency exchanges and other custodian wallet operators. However, there remains a particular fault-line that is more difficult to address, related to the newfound possibility for algorithmical entities (e.g. smart contracts) to effectively (i.e., technically) own digital assets (both licit and illicit). Reconstituting the boundaries of the legal order to encompass such a regime would require recognition of artificial entities being able to own digital assets, even without any human in the loop.

A striking example of a situation where the distinction between alegal and illegal acts became material in the context of blockchain governance was TheDAO attack. TheDAO was a decentralised investment fund deployed as a smart contract on the Ethereum blockchain in 2016 that raised USD $150 million dollars in one month. The peculiarity of this investment fund was that there was no centralised authority in charge of administering the funds; it was collectively managed by the investors themselves [START_REF] Kaal | Blockchain Innovation for Private Investment Funds Kedar, N[END_REF]. Each investor could participate in the fund's governance in proportion to the amount of funds they each had contributed. Whether people wanted to contribute more money into the fund, propose a particular investment, or vote on the projects that they would like TheDAO to invest in, every interaction had to be done-strictly and exclusively-via a smart contract transaction on the Ethereum blockchain (DuPont 2017). However, a vulnerability was found in the code of the smart contract governing TheDAO, which was exploited in order to drain the equivalent of over USD $60 million dollars from the fund [START_REF] Santos | The DAO: a million dollar lesson in blockchain governance[END_REF][START_REF] Mehar | Understanding a revolutionary and flawed grand experiment in blockchain: the DAO attack[END_REF]. This raised a heated debate within the Ethereum community as to whether this action qualified as theft-in that the draining of funds was counter to the original intentions of the parties and amounted to an illegitimate expropriation of their assets-or whether it could instead be regarded as a legitimate act-in that it did not actually infringe upon the (unintentionally flawed) provisions of the smart contract code [START_REF] Zhao | The DAO attack paradoxes in propositional logic[END_REF]): the code is the law .

Given that the issue has not been brought to court, one can only speculate as to how it would have been decided by a judge. Yet, even if the judge had found that such an action qualified as theft and that the stolen funds should therefore be returned to TheDAO, such a decision could hardly have been enforced. Indeed, TheDAO was not a registered company in any jurisdiction, but rather subsisted as a decentralised software entity, replicated on the computer of all network nodes participating in maintaining the Ethereum blockchain. As such, TheDAO was both everywhere and nowhere -ultimately challenging the spatial boundaries of the legal order, which typically address enforcement through private international law principles that seek to subject an entity to a particular territory. Even in comparison to the eBay example mentioned above, which could not entirely escape from being rooted in physical places, TheDAO was untethered from any physical location due to the lack of any centralised operator registered in a particular jurisdiction, the pseudonymity of (most of) its participants, the autonomy of the transaction system, as well as the absence of physical goods being transacted. Through its mere existence, TheDAO thus revealed a specific fault-line in the existing legal order. Indeed, as a general rule, and in the vast majority of jurisdictions, in order to acquire legal personality, companies or corporations must be registered or recognized by the laws of at least one jurisdiction. Such a territorial approach precludes the legal order from encompassing aspects of transnational unregistered organisations, such as DAOs, which do not have a presence in, or strong ties to, any specific national jurisdiction, yet tries to create an equivalent to legal personality and capacity through technological design. While the legal order could potentially expand its scope in order to assign legal personality to these DAOs,4 the mere fact of recognizing that such entities are not (necessarily) created by national law would challenge some of the basic axioms according to which artificial legal entities are presently regulated, requiring a radical reconstitution of the spatial boundaries of the law that would entail significant administrative, legal and political changes across multiple legal orders. This is where the fault-line arises.

Moreover, because of the characteristics of the Ethereum blockchain, the contentious transaction of TheDAO attack could not be reversed as easily as it could have been in the traditional financial system [START_REF] Wenker | Online Currencies, Real-World Chaos: The Struggle to Regulate the Rise Bitcoin[END_REF]. The autonomy and immutability of the blockchain code makes it impossible for any third-party authority to unilaterally seize stolen digital assets [START_REF] Raskin | Realm of the coin: Bitcoin and civil procedure[END_REF]. Thus, the traditional legal system offered limited recourse, as the lack of a centralised authority combined with the pseudonymity of participants made it virtually impossible for the original token holders to reclaim their loss through traditional legal means [START_REF] Kiviat | Beyond bitcoin: Issues in regulating blockchain tranactions[END_REF]. This further reinforces the idea that TheDAO provided an opening to another legality : its transnational nature, its technologically-driven regime of property rights, and the pseudonymity of most of its participants, enabled TheDAO to transgress, and effectively operate beyond the spatial , material , and subjective boundaries of the law.

Given the impossibility for any centralised authority to reverse the contentious transaction and restore the original balance of TheDAO, the only way to remedy this problem was for the whole Ethereum network to take a coordinated action and change the protocol of the underlying blockchain, so as to retrieve the allegedly stolen funds. Following heated community discussions and opinion gathering, the selected solution was to transfer the balance of the smart contract account where the stolen funds were stored to a new smart contract account, which had been specifically designed to allow for TheDAO investors to withdraw their funds. A significant majority of participating nodes agreed to update their software to reflect the 'forking' decision [START_REF] Voshmgir | Disrupting governance with blockchains and smart contracts[END_REF]), but some did not [START_REF] Mehar | Understanding a revolutionary and flawed grand experiment in blockchain: the DAO attack[END_REF]. This shows how, despite its allegedly alegal character, TheDAO was not immune from external intervention. Indeed, while no legal proceedings would have been successful in restoring TheDAO's balance, a collective community intervention ultimately succeeded in retrieving the funds. As such, TheDAO attack-and in particular its aftermath-can be assimilated to a "state of exception" that challenged the legal order of Ethereum's internal governance structure [START_REF] Reijers | Now the code runs itself: On-chain and off-chain governance of blockchain technologies[END_REF]. Deciding to hard fork was, in a sense, an alegal act in and of itself, testing both the temporal and material boundaries of the internal legal order established by the Ethereum blockchain network. Here, the temporal boundary of the Ethereum blockchain (which is reflected in the principles of temporality and non-retroactive modification of past transactions) was transformed into a fault-line, as resolving the case required either reinforcing the existing code-is-law approach (thereby accepting a loss of USD $60 million) or accepting new approach to blockchain governance that recognizes the legitimacy of external interventions, in exceptional circumstances, to reverse or invalidate recorded, yet undesirable transactions. In material terms, the modification of the underlying blockchain protocol constituted a material fault-line, in that it undermined the fundamental claim to immutability as regards the protocol or code of existing blockchain-based systems (although not doing so would support acts that some considered to be unjust, or even illegal). Such a coordinated action was ultimately the result of a collective political decision to retrieve the allegedly stolen funds. Though there is no "sovereign" on the Ethereum network, the coordinated action of all network nodes could successfully modify the network protocol [START_REF] Reijers | Now the code runs itself: On-chain and off-chain governance of blockchain technologies[END_REF]). Thus, even in the most alegal spaces -in xenotopias (Lindahl 2018, 29, 65) -governance continues to have an important role to play.

Policies for Blockchain Governance

Policymakers can respond to the alegal characteristics of blockchain technology in one of two ways: either by extending the scope of existing legal provisions in order to encompass new activities that should be covered by the law, or by reducing the law's scope in order to exclude activities that should not have been encompassed in the first place. In the first approach, policymakers may decide to tackle the alegality of blockchain technology by bringing some of the activities necessary for ensuring the proper operation or maintenance of a blockchain-based network within the scope of the law. Alternatively, in the second approach, they may decide to deliberately exclude certain activities from the scope of the legal order by providing legal immunities allowing for these activities to take place without the usual constraints of the legal system. This explicit exclusion of activities from the traditional legal order would amount to making the alegal into the extralegal .

Despite their resistance to inclusion within a legal order, alegal acts are not entirely immune to the legal system. Indeed, the aftermath of the TheDAO attack provided a clear demonstration that blockchain-based platforms do not exist in a vacuum (De Filippi 2018); they subsist within a larger ecosystem, and their operations depends on the actions of a variety of actors with divergent or competing interests (Bohme et al. 2015), which are themselves subject to the law.

Accordingly, even if the traditional means of regulation are not readily applicable to some of the operations of a blockchain, there are other ways in which intervention remains, nonetheless, possible [START_REF] De Filippi | Blockchain and the law: The rule of code[END_REF]. Potential means of intervention include, inter alia , regulating intermediaries, commercial operators, or mining pools and establishing arbitration systems between governments and cryptocommunities [START_REF] Dimitropoulos | The Law of Blockchain[END_REF](Dimitropoulos , 1191)). Regulators and policy makers may attempt to impose responsibilities or liabilities onto these actors. This has previously been the approach with regulating the Internet as a global network. Rather than trying to directly regulate the behaviours of Internet users, governments sought to instead regulate strategic gateways and chokepoints, such as Internet service providers. While these approaches to regulation have not yet gained much traction in the blockchain policy arena, the identification of new mechanisms to control or influence the operations of a blockchain-based system will become increasingly necessary [START_REF] Koens | The drivers behind blockchain adoption: the rationality of irrational choices[END_REF], as the technology gets adopted in the context of private companies, public sector agencies or other institutional frameworks [START_REF] Sulkowski | Blockchain, Law, and Business Supply Chains: The Need for Governance and Legal Frameworks to Achieve Sustainability[END_REF]). An important question to address-as [START_REF] Johnson | Law and Borders--The Rise of Law in Cyberspace[END_REF]Post (1996, 1375) had already observed with respect to cyberspace-is who can legitimately exercise control or influence a public and permissionless blockchain network? Relatedly, how can this be done so that the network retains its distributed nature?

It is widely acknowledged today that centralised cryptocurrency exchanges and custodian wallet providers have an important role to play in blockchain governance, due to the fact that they act as intermediary operators for all of their users, many of whom will automatically follow any decisions the intermediary takes (with regard to e.g., choosing one fork over the other). As these intermediaries typically have a presence in a jurisdiction due to licensing requirements, they are also particularly vulnerable to governmental pressures in the countries they operate in. In the U.S. and Europe, cryptocurrency exchanges are required to comply with KYC and Anti-Money Laundering (AML) regulations and some governments may promote the 'black-listing' of specific addresses, to prevent transactions with persons who have been involved in criminal activities. Such approaches, while effective in addressing specific policy concerns, have the (undesirable) effect of reducing the decentralising potential of the networks, by reinforcing the power and influence of intermediaries.

The contention of [START_REF] Walch | Code (Rs) We Trust: Software Developers as Fiduciaries in Public Blockchains[END_REF] that developers contributing to the code of public blockchain networks like Bitcoin hold fiduciary duties (by default) towards users or third-party operators relying on these networks is also untenable. Firstly, it imposes a duty when open source software developers have generally enjoyed exemptions from liability for the software they produce, subject to the necessary warranty disclaimers being made [START_REF] Dixon | Open source software law[END_REF]). Secondly, it misunderstands how blockchain networks operate. These developers, unlike centralised platform operators, cannot impose changes onto a network and rely on the active participation and cooperation of network participants to modifications and upgrades [START_REF] Haque | Blockchain Development and Fiduciary Duty[END_REF]). The same is true for the other types of actors involved in the governance of a blockchain network-be they cryptocurrency holders, miners, validators, commercial operators, influencers, etc (De Filippi & McMullen 2018). Hence, while it is legitimate to hold specific third-parties accountable for their own actions (e.g., for extortion), it would be problematic and unjust to hold individual actors responsible for actions collectively undertaken by network participants, which they do not single-handedly control.

In some instances where there is alleged criminal or civil liability arising from an act, the state may take the practical step of pursuing those persons who are within their jurisdiction-even if their individual responsibility is marginal. The fear of potential liability may act as a deterrent for persons who reside in particularly litigious jurisdictions from engaging in blockchain governance [START_REF] Zetzsche | The distributed liability of distributed ledgers: Legal risks of blockchain[END_REF]. Paradoxically, a state's ability to influence blockchain governance may become more circumscribed as a result of these practises, since those who participate in the governance of a blockchain-based system will try to reside and operate outside their jurisdiction.

These suggested approaches to influence the operations of blockchain-based systems are limited in that they do not properly account for the alegal characteristics of these systems. They merely replicate the approach adopted in the context of Internet governance, focusing on those players who can be more easily regulated. These approaches reinforce the boundaries of the legal order through the enactment of draconian regulations, rather than exploring the possibility of reconstituting these boundaries in light of the alegality of new technological developments.

Given the specificities of blockchain technology, whose governance involves a multiplicity of actors and interconnected layers, it might be useful to consider alternative means of intervention for policy makers to contribute to improving the governance of blockchain-based systems, while being mindful of their distinctive properties and characteristics. Any policy proposal must account for the alegal features of public, permissionless blockchains (such as the impossibility for any one jurisdiction to shut down the entire network), as well as the potential implications of every policy choice, including its ability to alter the collective identity of the legal order. As Lindahl reminds us, alegal challenges that cannot be accommodated into a legal order, will not disappear even with the most adroit policy prescriptions (Lindahl 2019, 23). Indeed, his overarching suggestion is that when casting the boundaries of a legal order, one should always acknowledge that there will always be a persistent and unorderable outside to that legal order (Lindahl 2019, 28).

Instead of undertaking extensive legal reforms to regulate these blockchain-based systems in an all-encompassing way, which might require either a radical reformulation of the legal order or an actual modification of the underlying infrastructure and political structure of these systems, we propose that policies leverage the notions of functional equivalence and regulatory equivalence as an alternative means of bringing these systems within the scope of the legal order. Functional equivalence relies on analysing the function of a particular artefact (e.g., paper document) with a view to determining how those functions could be fulfilled through another type of artefact (e.g., electronic document) within a particular legal context (e.g., contract law). Functional equivalence is thus an efficient way to address alegality of the second type-i.e., all these acts that are not yet intelligible to the law, but that easily could be intelligible, because expanding the boundaries of the law in order to bring them into scope would not change much of the content nor fundamentally challenge the identity of the legal order. Indeed, the concept of functional equivalence has already been adopted by certain laws, such as the UNCITRAL Model Law for Electronic Commerce which establishes functional equivalence between a paper-based document and an electronic document for the purpose of contracting. Regulatory equivalence goes one step further, by analysing the purpose of a particular legal or regulatory provision (e.g., auditing for the purpose of verifying credit-worthiness) to determine under which conditions the same purpose could be achieved, in a wholly different manner, through alternative technological means (e.g., using fully collateralized smart contracts to eliminate counterparty-risk). Regulatory equivalence is also relevant in the alegality context, because it allows for objects or activities that are outside of the legal order to be incorporated within it, to the extent that they contribute to supporting an equivalent objective or purpose as some of the legal provisions of the legal order.

To assess whether new usages of blockchain technology can comply with existing regulatory requirements (functional equivalence) or provide equivalent types of safeguards/guarantees to promote existing policy objectives (regulatory equivalence), policymakers around the world should more widely encourage the creation of "regulatory sandboxes". Regulatory sandboxes are mechanisms, often used in the financial industry, to establish a controlled environment for early-stage firms to experiment with new technologies or business models, while benefiting from temporary exemptions from existing financial regulations (e.g., unsophisticated investor protection) and legal requirements (e.g., customer protection) within that environment. The term "regulatory sandbox" was coined in 2015 by the Financial Conduct Authority (FCA) in the UK, to describe the environment in which there is an opportunity to develop "mutual learning about the impact of current regulation on new financial products and, more generally, in order to reduce the phase of 'time to market' in financial innovation" (Mangano 2018, 728). A few projects building blockchain-based systems have already gone through regulatory sandboxes in the UK 5 and elsewhere.

To understand how regulatory sandboxes can be useful for establishing functional and regulatory equivalence, consider the example of Initial Coin Offerings (ICOs). The costs and regulatory burdens of complying with securities regulations is often high enough to dissuade many projects from even trying. Yet, well-designed technological solutions could ensure transparency and contribute to substantially reducing the risk of investors,6 potentially justifying the establishment of a more lenient regulatory regime for all these initiatives that were to adopt these solutions (Collomb, De Filippi & Sok, 2019).

The benefit of relying on regulatory sandboxes is that they enable regulators and policy makers to delegate the task of coming up with innovative solutions concerning the regulation of blockchain technology to the actors directly involved in the use of that technology (and who have a better understanding of its respective challenges and opportunities). Over time, if policymakers were to recognize these blockchain-based solutions as either functionally or regulatorily equivalent to the purpose of existing legal provisions, the granting of regulatory exemptions could be implemented outside of the regulatory sandbox, thereby reducing the burden of legal and regulatory compliance to all these actors who would integrate these solutions into their own information system. If successful, this approach would thus support the establishment of novel blockchain-based solutions that voluntarily comply with existing policy and regulations, in order to benefit from these regulatory exemptions, without unduly sacrificing the decentralised nature of these systems. This is-in the words of Agamben (1998, 7, 22)-a response to alegality that relies on the notion of inclusion by exclusion : by deliberately covering certain activities through legal exemptions, the legal order is simultaneously expanding its scope to encompass these activities, and committing to not interfering with these activities, provided that they remain within the scope of the exemption. We acknowledge that this approach, which creates greater room for a nascent private legal order for blockchain-based systems ( lex cryptographica ) will come with its own limits and boundaries, in the sense that this private legal order will still have an inside and an (unordered) outside. Accordingly, lex cryptographica will have to face its own set of alegal challenges that stalks every "emergent global legal order like its shadow" (Lindahl 2019, 32). Instead, we see our recommendations as enabling policymakers to navigate the various fault-lines revealed by the operation of blockchain-based systems in a manner that is consistent with policy objectives and regulatory requirements, while preserving the distinctive properties and accommodating the alegal characteristics of these systems.

Conclusion

Blockchain networks present distinctive characteristics that distinguish them from traditional centralised online platforms. In particular, the inherent resilience, incorruptibility, tamper-resistance, and operational autonomy of blockchain-based systems have led some people to describe them as alegal -in the sense that they are neither legal nor illegal, they operate outside of the reach of the law and resist inclusion into a legal order. While the notion of alegality has usually been used to refer to specific actions or activities performed by humans, this article also argues that alegality can be used to refer to specific technological artefacts, whose inherent characteristics facilitate new types of alegal acts. By introducing the notion of "alegality by design", this paper has shown that the technological design of many blockchain-based systems can support and promote alegal acts through technological affordances. Yet, such a qualification does not relegate these systems to alegality by virtue of them being unregulatable "forces of nature"-as originally claimed by [START_REF] Wood | Alegality: Systems that can't care. CoinScrum and Proof of Work Media: Tools for the Future[END_REF]. Rather, blockchain networks and the systems that govern them are human, all too human , subject to the social norms and economic imperatives that originate from particular modes of social life.

The proposed policy approach of encouraging the use of regulatory sandboxes opens a fresh set of research questions: what are some of the technological solutions that can comply with existing regulatory requirements or provide equivalent types of safeguards/guarantees to promote existing policy objectives? What are the legal and socio-economic limitations of using regulatory sandboxes [START_REF] Ranchordás | Experimental Regulations and Regulatory Sandboxes -Law Without Order? Law & Method[END_REF], particularly in the context of blockchain governance? These are some of the questions that need to be explored in future research.

Lindahl (2008, p. 126) claimed that all four boundaries of a legal order were transgressed by border crossings, but here we focus on the spatial dimension.

In setting out the ontology of the Vita Activa, Arendt claims that technologically mediated activities would be the activities of homo faber , belonging to the realm of 'work', not political action. Yet, within Arendt's oeuvre there is the unexplored possibility of hybridity, of what might be named "work in the mode of action"[START_REF] Reijers | Responsible Innovation between Virtue and Governance: Revisiting Arendt's Notion of Work as Action[END_REF]. Such an activity aims at creating a durable world (a built environment with institutions) while at the same time being open to the plurality of human action.

AA v Persons Unknown & Ors, Re Bitcoin [201 9] EWHC 3556 (Comm) (13 December 2019), at [61]; Vorotyntseva v Money-Ltd (T/A Nebus.com) [2018] 9 EWHC 2596 (Ch), at [13].

For one example of such an initiative, see COALA, DAO Model Law (2021), available at https://coala.global/wp-content/uploads/2021/06/DAO-Model-Law.pdf

For example, if all transactions are executed on a public blockchain, one cannot claim to have undertaken a transaction that does not appear on the blockchain, or conversely to not have engaged in a transaction that does appear on the blockchain. This could go towards replacing expensive reporting obligations.5 For example, the sixth cohort of the UK Financial Conduct Authority's regulatory sandbox had businesses using blockchain for SME invoice financing, tracing donations, and issuing security tokens. https://www.fca.org.uk/firms/regulatory-sandbox/regulatory-sandbox-cohort-6 . In Singapore, crypto-custodian firms have also graduated from the Monetary Authority of Singapore's regulatory sandbox. https://www.mas.gov.sg/development/fintech/sandbox (both accessed 28 December 2021).

Acknowledgment

This research is funded by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (Grant Agreement No. 865856).


Paula Gordo-Gregorio
email: paula.gordogregorio.auditeur@lecnam.netecle

Keywords: BIM, Database, Digital Twin, Information

. In the construction field, the digital and information revolution has given rise to BIM technologies, which have changed the processes of design, construction, and building management (Tulenheimo, 2015). This article sheds light on the current construction processes from a different perspective through the analysis of three study cases. Until now, building projects were mainly analyzed through their plans and geometry. We suggest that BIM projects should also be studied through the analysis of the information stored in the "digital twin" of the building. We consider a digital twin as a database linked to the building's digital geometry. We make the hypothesis that the study of this database and the way in which the actor's structure and manage this information, will give a better insight on how functions these buildings.

Introduction

In "BIM" projects, the process of creating and recovering building data is integral to the building construction project. The analysis of exploratory interviews carried out between June 2018 and October 2019 revealed the prominence of the processes relating to the introduction and retrieval of building data in the studied projects, to the extent of becoming a separate project, which we call the Building Data Project; We formulate the hypothesis that the data project of the building, in the multiplicity of its dimensions (economic, industrial, environmental, etc.) is a good observatory of the organization and the functioning of the system of actors across the various phases of the construction project (programming, design, realization, management). In this article we aim to present the historical background and genesis of building data projects and the new insights that emerge from studying building data. First, we present the genesis of building data through a historical lens. Then, we introduce a new emerging actor system identified from the analysis of different case studies observed within a technical design office and finally we present some of the building information-related challenges encountered by these actors. Studies that we previously conducted found a link between information and the system of actors (Gordo-Gregorio, 0 0) 01 ). Through this paper, we build on those indings and further elaborate and describe what we called the Building Data Project and its usefulness on studying the transformation of the construction field from an information-based approach.

2 The origin of "building data" and the building data project

The history of building data

The history of data classification is much older and independent of the computer tools [START_REF] Picon | Culture numérique et architecture: une introduction[END_REF]. In the course of the history of architecture and construction, there came a time, at the end of the Middle-Ages, when the master builder was less and less present on the construction site [START_REF] Fregier | Et de s r la repr sentation des composantes morphologiq es de donn es d projet architect ral dans n conte te de C.A.O. GAMSAU[END_REF]. It was at this point that iconographic data and written data began to be distinguished. The notes on the drawings, originally very informal, became the more and more important. Finally these notes gave rise to the "written documents" of the project.

Authors such as A. Picon and C. M. Eastman, who have worked on the history of architecture from a technological perspective, explained how the process of annotating drawings evolved with the advent of the industrial revolution. Building components and materials became more diverse and led to increasingly complex specifications to the point where their standardization and structuring became necessary. The classification, characterization or prioritization of the building data could be done in various ways. These classifications started on the 50s-60s with the SfB classification in Sweden (1950) and Masterformat in the US (1963) and they had a huge developpement on the 80s and 90s [START_REF] Afsari | A comparison of constr ction classification s stems sed for classif ing b ilding prod ct models[END_REF]. Nowadays, there is a wide variety of classification systems, international classifications such as Uniformat, Omniclass, and Uniclass, created by the Construction Specifications Institute in the United States and the Construction Project Information Committee are among the most widely used. These classifications have been integrated into the ISO building standards (ISO 19650 and ISO 12006) even if they have been developed in the Anglo-Saxon world, and they are linked to the modes of organization of the design process in these countries.

The arrival of information technology also responded to this exponential increase in the quantity of data to be transmitted in the construction process. The research work developed in the field of CAD since the 1980s, in France (INPROBAT team, 1986) and abroad [START_REF] Eastman | Building product models: computer environments, supporting design and construction[END_REF], gave rise to less rigid classifications and proposed separate groups of data according to the type of actor who would have to recover them (Quintrand, 1985). These classifications were reworked in the late 1990s by researchers interested in the management of building description information (Ameziane, 1998). The computer database projects, at that time, specifically distinguished the dimensional, functional, technical and economic characteristics [START_REF] Hamani | Un syst me d'information pour le bâtiment-Elaboration d'un mod le conceptuel de données pour les ouvrages façonnés en place issus de la production de bâtiment[END_REF]. The developments in the field of computer science, together with the standardization of construction information and procedures, gave rise to BIM software.

At the end of the 20th century, in "BIM" projects, the creation of the building database transformed into a separate project, what we refer to as the Building Data Project. Following the principle that a project represents a global approach that plans to answer an issue or a problem (Boutinet, 1998) [START_REF] Prost | Pratiques de projet en architecture: le tournant silencieux: essai[END_REF], we assume that the data project responds to the owners' informational requirements. In this "project", the actors choose to create and retrieve data during the programming, design, construction, and operation phases. The data introduced by the actors in these digital models is used in many different ways, to obtain quantities, to facilitate energy simulation calculations, to carry out life cycle analysis, to prepare the model for operation and maintenance, etc. The building data project thus shares its temporality and part of the actor system with the building construction project. We have seen that in BIM projects, "iconographic data" and "written data" are distinguished in the same way that they used to be distinguished in the past. These data are evaluated by two scales that are used by the client to measure the level of development of projects in BIM: the LOD (Level of Detail) and the LOI (Level of Information).

The building data project and digital twins

The digital twin is an expression that has been mainly used in the context of heritage (Jouan, 2019) for the control and management of constructed buildings, the so-called HBIM (Historic Building Information Modelling). We consider the digital twin as the addition of the database and the 3D geometry, even if the notion of digital twin is much more complex and inherited from the aerospace field. This concept also includes the further management of the building, the connection between the real and virtual world, simulations etc. [START_REF] Boje | To ards a semantic Constr ction Digital T in: Directions for f t re research[END_REF] However, 3D modeling existed before BIM and we can find 3D software that is not BIM software because they don't integrate the information management. In order to focus on a pure informational approach, we decided to separate the database from the 3D geometry by analyzing the creation of the building database. In a traditional project, the Building Construction Project produces a building. However, nowadays the BIM project produces two outputs: the building itself and its digital twin (Figure 1). The analysis of this new project emerging from informational issues gives us a better understanding of the new issues in the construction field today. The division between the level of detail in modeling and the level of detail in information -LoD and LoI-is characteristic of each project [START_REF] Ma Reli | Le el of De elopment s[END_REF]. We also find the expression LoG for the level of detail of the geometry in order not to confuse with the LOD or level of development which is the addition of the level of geometrical and informational detail (LOD=LoI+(LoD/LoG)). Most research in architecture has been based on geometrical questions, which in this case would be related to the LoG of the project. Developing research that is purely based on informational issues in the construction field-, i.e., the LoI of the project -implies a new approach in the observation and analysis of BIM projects.

3 The building data project as an observatory of the system of actors Another consequence of industrialization is the specialization of activities and the emergence of new professions. It produced an increase in the number of actors intervening in the construction project, and the notions of collaboration and cooperation became key words in the semantic field of the construction trades. Emerging work methodologies, new functions, and new trades have appeared and have upset the traditional division of labor between professionals (Teulier, 2017). The new tasks associated to the "BIM" actors in these projects do not correspond to the traditional tasks they used to undertake. Designers and construction companies must therefore face a set of new tasks that did not previously exist: the parameterization, the implementation of Excel tables structuring the data to be retrieved or the verification of the introduction of information. The methodology that we have followed is based on triangulation and we present the results obtained from 3 case studies (2 educational buildings and 1 office building) in which information becomes a problem of collaboration between the stakeholders.

Methods

The methodological choice during the analysis of the case studies is based on the triangulation analysis (Denzin, 1

) between the contractual documents (BIM speci ications, BIM protocol and BIM notice), the BIM model databases and the semi-structured interviews carried out with the project actors. Even though in this article we present the general background of the case studies, the hypotheses and observations are based on the results of each study case and the participant observation within the company ALTO Ingeńierie from 01 to 0 1. Participatory observation in these projects involves all project stakeholders beyond those working at ALTO Ingeńierie.

The analysis of the projects started with the documentary analysis (Figure ). The protocols and speci ications give the context of data collection at the "contractual" level. Then, the interviews bring the mental representations of the actors and their experiences. Finally, the study of the digital models allowed us to verify the informational stakes described in the contractual documents and in the actors' statements.

Findings: A new system of actors

The person in charge of implementing BIM methodology is the BIM manager. In most cases, project owners do not have the skills required for the completion of the associated tasks and call upon the BIM assistant (AMO BIM in France), a kind of "BIM manager", to supervise the progress of the BIM project and in particular the information relevant to the client's interests. While the BIM manager becomes, in general, a full-fledged job, the new missions of BIM coordinator and BIM modeler/producer, are adapting in most of the observed projects to the traditional jobs of project manager and draftsman through the addition of new tasks related to the introduction of building data in the BIM model.

Currently, not all project stakeholders work within the building data project. This project is developed in parallel only with a part of the actors of the building construction project. Beyond the issues related to purely geometric modeling in so-called "BIM" projects, we focus on the informational tasks developed by each "BIM" actor. From the typical diagram of a BIM project -BIM Manager, BIM Coordinator, BIM modeler-(Davies et al., 2017), we have created a "hypothesis" diagram (figure 3) that represents the informational tasks of the system of actors in the building data project. The observation of the actors included in the diagram provided us with answers about the mutations in the stakes and work methodologies of the actors in the construction field nowadays.

The building data project is the main difference between the traditional construction project and the so-called "BIM" projects because the 3D modelling already existed in some traditional projects and it didn't change or modify workflows, tasks or methodologies. The project starts from a "list of needs" requested, normally, by the owner, the future operator of the building or the entity that sets up the "BIM" process from the drafting of the BIM specifications. Then, the BIM manager by drafting the "BIM Protocol", will set up a whole process of data creation and recovery. These two documents become a record of the evolution of the client's interests and his discussions with the rest of the actors (economist, architect, environmental design office, etc.).

In the case studies analyzed, we have observed that the system of actors can vary from one project to another, particularly with respect to the actors who work on the selection of the building data (Figure 4). We also observed that the different distribution of roles in the choice of data produces very different situations of power struggle. Consequently, the creation, storage and retrieval of building data give rise to many situations of negotiation: who chooses the types of data, who enters them, who verifies them, how the actors will retrieve them and when, etc.

Findings: BIM information problems

In the data project, there is set of tasks that are distributed, and a coordinator, the BIM Manager, who verifies the smooth running of the project. Not all actors integrate the needs of the other actors in their approach because in most cases this causes an overload of work. Consequently, this coordination is based on a constant negotiation arbitrated by the BIM manager and in which one actor asks another to model in such and such a way, or to provide such and such information so that it can be recovered. These are new tasks which, in general, according to the actors interviewed, are not remunerated as added value. These tasks usually become an additional workload which generates problems, discussions and changes in work methodologies. Moreover, the power relationships will become key during these negotiations, in which the BIM manager and the client will be dominant in relation to the other actors, also giving prevalence to the entity in which the BIM manager is registered (architectural studio, engineering company, etc.).

We have seen that the development of the design process of the data project is also conditioned by the construction phases of the building (programming, design, construction, operation and demolition) (Table 1). The initial data are created by the project owner in the programming phase to allow a follow-up in the design phase (surfaces, functionalities etc.). However, other data such as economic data or data related to materials are produced during the design phase by the designers. Not all the data are permanent in the project, for example, data that refer to the location of equipment or structural beams during the construction phase will not be useful during the operation phase and will disappear at the end of the phase for which they were designed (Case Study 1). This study therefore highlights the need to identify the data lifecycle, in all phases, in order to better understand its creation and evolution throughout the construction project. Since the beginning of the design phase of the project, the owner has established a table that structures the data for the operation of the building. An exhaustive parameterization is integrated since the beginning of the design in the model. The specifications require the recovery of quantities from the model.

Within the framework of an environmental mission of life cycle assessment (LCA), the project manager tries to obtain information on the building materials from the digital model. The environmental project manager establishes a specification for the information of materials

INFORMATIONAL ISSUES INFORMATIONAL ISSUES

INFORMATIONAL ISSUES 1.The client decides to change the facility manager and everything had to be reconfigured. For the new facility manager, the data for maintenance had to be filled in by month (time parameters) and the tasks to develop every month had to be introduced as the information of the month parameter. However, the previous parametrization introduced the maintenance tasks as parameters and they were filled with the data "periodicity. ". As a result, the data are the same but the structure is completely different.

1. Designers describe the model as unreliable. It lacks quantitative data.

1.The construction materials are not well detailed.

2.In the models, each object has about ten parameters and codifications introduced in the BIM model. This situation has caused an overload of work for the designers.

2.The parameterization of the model has been done for the operation and maintenance of the devices. WHY?

WHY? WHY? Facility management' tools are not adapted to the BIM process. Before, the facility manager's job and the designer's job were not linked but now they need to work together if they want to retrieve data from the BIM model. In addition we can find IT problems on this process.

Different BIM Managers for each phase of the project, less communication between the BIM Manager and the designers. The BIM Manager belongs to the client company and he is disconnected from the design team.

Absence of concerns related to LCA and BIM, the BIM LCA specifications are a request from the design team (the environmental company) and not from the client. In addition, the BIM Manager works for the architectural firm who is in charge of introducing the characteristics of materials, and it would produce a workload to his firm.

Lack of circular economy concerns from the design team and the owner. The companies are not yet ready to this kind of analysis on BIM Models and lack of specifications from the owner. In addition, the BIM Manager belongs to the engineering consulting firm and he cared more about facility management information than about materials.

Educational building (University) 2. Very little information about the steel or the supplier and it was impossible to establish a traceability from the database of the CASE STUDY 1 SITUATION This project was chosen within the framework of a Circular Economy Project on buildings. The project considered analyzing the traceability of the steel of the beams. The selected project had BIM mockups that corresponded to the end of the construction site.

INFORMATIONAL ISSUES 1. Devices (for exemple: lamps, air conditioning machine etc.) very well described and with maintenance schedules however rest of the information had very different levels of detail.

WHY?

4 Discussion: Building data in BIM project research

Building data in BIM project research

The building data project is not a concept that we usually find in the BIM literature, however, building data and building databases are very recurrent notions. The repetition of these notions in BIM research highlights the importance of information and data in the construction projects nowadays. The kind of research that takes into account information in BIM projects usually addresses the new technologies of information and communication (Tulenheimo, 2015), the energy performance of the buildings [START_REF] Lange | Visualisation interactive de données hétérog nes pour l'amélioration des dépenses énergétiques du bâtiment[END_REF] or the facility management (Dao & Forgues, 2013) and the management of the built cultural heritage (Jouan, 2019).

The level of information of the BIM project gives us an insight about how much information is taken into account in the project and what are the parameters that are created and filled with data. The LOI can be requested by the BIM Manager or the future owner of the building by sending an Excel File with the most important parameters (Figure 4). On this kind of files we can introduce parameters that will help on facility management or that will provide us with information to run energy performance simulations and consequently, information became important on these research topics. In addition, facility management and the management of built cultural heritage are based on data and excel files. Facility management and BIM research are focused on how to connect the BIM model database to the facility management and the heritage management tools, but also on how to enhance occupants ' comfort (Alavi et al., 2021). For the energy performance and other environmental analyses, this data is extremely important because in a traditional construction project, these actors spend a lot of time searching for information about materials, energy coefficients or measurements. However, if the parameters that these actors need to run the simulations are properly filled into the BIM Model, it will facilitate their tasks. We can observe that in all these approaches we find an interest in understanding certain aspects of the building database. Nevertheless, in the building data project our goal is to be able to understand all the important aspects related to the building database for all the project stakeholders.

System of actors in BIM project research

The complexity of the system of actors in BIM projects is also linked to each profession. The dif iculties of the actors will be linked to the constraints of their ield of work, and we will ind different constraints between architects, engineers, facility managers, economists etc. In the ield of architecture, it is possible that architects' fears about BIM are rooted in the profession's historical background and its connection to hand-drawing. Nevertheless, these practices are changing and currently there are many architectural irms, regardless of their size, that are implementing BIM work processes (Hochscheid and Halin, 0 0). The sociologist Guy Tapie ( 000), observed that young architects were the real driving force behind the early days of CAD computerization in the architectural irms. This effect, which is linked to the youth of the people involved in the project, could also be applied in the technical design of ices for the engineers' profession.

The constraints encountered by the actors of the project are linked to the jobs they develop but also to the phase of the project in which they intervene. In the case of facility managers, their dif iculties are more related to the lack of connections between the digital models and the facility management tools, and to the fact that facility managers are very little present during the design process (Liu, 01 ) (Motamedi,01 ). Nowadays, their involvement from the beginning of the project is very important because it allows to structure the project data from the beginning. Currently there is a lot of research going on to establish the best way to connect the building management with the digital twin by taking the data that has been illed in, with the data collected from the sensors placed in the building (Motawa, 01 ) (Da e, 2018) [START_REF] Akcamete | Potential tili ation of b ilding information models for planning maintenance acti ities[END_REF]. This kind of research projects aims to capture/retrieve the information for the operation of buildings, which is already stored in the digital model. Part of this research is focused on the classi ication of information in order to ind classi ications, such as the COBIE format, in order to classify the information and to structure it in the same way during the construction phases and during the management phases (La & Ja adekar, 2014).

Conclusion

In this article we have not been able to go into the details of the analysis of each case study in order to give a general picture of the layout of the building data project. In this context, we are also developing, as part of this research project, a classi ication or analysis grid that allows us to classify the project information according to the concerns of the project actors.

We propose to the observation of work methodologies through the building data project, as it represents the singularity of BIM projects compared to traditional projects. By taking "building data" as the object of study, we sought to understand the impact of the introduction of information in so-called "BIM" projects on the construction ield. Through the case studies, we have observed that these data included information on the characteristics of materials, dimensions, energy simulations of the building, maintenance schedules of equipment, surfaces, occupancy modalities or functions of spaces, etc. As these data are quite heterogeneous, their classi ication and organization are necessary.

The data project also provides an opening to new quality issues, which will add complexity to the design process. The in luence of the data project on the construction project could be directed towards notions like circular economy, health, energy performance, cultural heritage etc. A whole set of new concerns that, through the building data project, ind a way to be integrated into a design process that previously was much more focused on purely geometric issues. Thus, the building data project appears as a promising opportunity to analyze new perspectives on the building design process.

On future works we propose the analysis of the collaboration/cooperation processes within the system of actors developed for each data project should shed light on the main collaboration constraints that exist today in this new type of construction project. The working methodologies around a building data project tend to converge in order to arrive at a semantic and methodological understanding common to all the actors of the project. The term collaboration appears today in almost all the publications of the professional or scienti ic about "BIM", however this collaboration is not yet real and it remains one of the most important constraints since each actor has different concerns and needs.

Another interesting question to explore concerns product related data, and the main standards (ISO and ISO ). Even if these standards become too technical and do not raise enough information about the concerns of the actors, the huge variety of parameters to be illed in these objects highlights the importance of thinking about the information content of the objects.

Finally, we also propose a third approach that concerns the life of the data and the analysis of information that disappears during the project, in order to understand what is intentional or what is the result of poor project management.

Figure 1 .

 1 Figure 1. Comparison between traditional Project and BIM project. Source: Gordo-Gregorio, 2020

Figure .

 . Figure . Qualitative research methodology based in triangulation. Source: Prepared by the author 0 0.

Figure 3 .

 3 Figure 3. Adaptation of the BIM flowchart to the tasks developed by the Building Data Project stakeholders. Source: Prepared by the author, 2021.

Figure 4 .

 4 Figure 4. Diagram of the stakeholder system in the three case studies analyzed. Source: Prepared by the author, 2020.

Figure 5 .

 5 Figure 5. Example of a LOI Table. Source: Case Study at the company ALTO Ingénierie.

Table 1 .

 1 Analysis of informational conflicts in the case studies. Source: Prepared by the author, 2021.

	CASE STUDY 1	CASE STUDY 2	CASE STUDY 3
	Educational building (University)	Office building	Educational building (High
			School)
	SITUATION	SITUATION	SITUATION
	The facility manager helped the
	designers to structure the database in
	order to produce retrievable Excels for its
	maintenance operation tool.

Proc. of the Conference CIB W78 2021, 11-15 October 2021, Luxembourg