Dr Nikhat Akhtar

Dr Bedine Kerim

Dr Yusuf Perwej

Dr Anurag Tiwari

Dr Sheeba Praveen

A Comprehensive Overview of Privacy and Data Security for Cloud Storage

Keywords: Cloud Computing, Data Security, Artificial Intelligence as a Service (AIaaS), Cloud Storage, Data Access Control, Data Privacy

People used to carry their documents about on CDs only a few years ago. Many people have recently turned to memory sticks. Cloud computing, in this case, refers to the capacity to access and edit data stored on remote servers from any Internet-connected platform. Cloud computing is a self-service Internet infrastructure that allows people to access computing resources at any location worldwide. The world has altered as a result of cloud computing. Cloud computing can be thought of as a new computing typology that can provide ondemand services at a low cost. By increasing the capacity and flexibility of data storage and providing scalable compute and processing power that fits the dynamic data requirements, cloud computing has aided the advancement of IT to higher heights. In the field of information technology, privacy and data security have long been a serious concern. It becomes more severe in the cloud computing environment because data is stored in multiple locations, often across the globe. Users' primary challenges regarding the cloud technology revolve around data security and privacy. We conduct a thorough assessment of the literature on data security and privacy issues, data encryption technologies, and related countermeasures in cloud storage systems in this study. Ubiquitous network connectivity, location-independent resource pooling, quick resource flexibility, usage-based pricing, and risk transference are all features of cloud computing.

I. INTRODUCTION

Today scenario, big data [START_REF] Perwej | An Experiential Study of the Big Data[END_REF] is now rapidly developing in all research and engineering areas, including physical, Medical Internet of Things (MIoT) [START_REF] Catarinucci | An iot-aware architecture for smart healthcare systems[END_REF], biological, and biomedical sciences, due to the rapid expansion of networking, data storage, and data collection capacity. The rate of data production has grown significantly in recent years. Many organizations are looking for cost-effective ways to store and analyses large amounts of data generated by a variety of sources, including high-throughput equipment, sensors, and connected devices. Big data [START_REF] Akhtar | A Perusal of Big Data Classification and Hadoop Technology[END_REF] technologies can take advantage of cloud computing [START_REF] Zhang | Research on the security mechanism of cloud computing service model[END_REF] to deliver major benefits, such as the capability to build, connect, configure, and reconfigure virtualized resources on demand with automated tools. Cloud computing is a new paradigm that is altering how institutions, businesses, organizations, and individuals see and use various software systems [START_REF] Shynu | A comprehensive survey and analysis on access control schemes in cloud environment[END_REF]. Organizations that use cloudbased solutions don't have to host their software or manage their own servers [START_REF] Aluvalu | A survey on access control models in cloud computing[END_REF]. The cloud computing is made up of hardware and software resources that are made available as managed external services over the internet.

Advanced software applications and high-end server computer networks are used to provide these services.

With the rapid expansion of computer, storage, and communication technology, the cloud computing [START_REF] Li | Secure attribute-based data sharing for resourcelimited users in cloud computing[END_REF] is a new computing model that may give users with programmable and shared resources. Cloud computing [START_REF] Xiao | Security and privacy in cloud computing[END_REF] providers link a huge number of nodes and network devices [START_REF] Yusuf Perwej | The Future of Internet of Things (IoT) and Its Empowering Technology[END_REF] to create one or more big data centers. Then they offer infrastructure, platform, storage, and software services, all of which are centered on data centers. The most well-known technology in the world is cloud computing. It offers a variety of services to its customers, and cloud storage is one of the most important aspects of cloud computing [START_REF] Sun | Surveying and analyzingsecurity, privacy and trust issues in cloud computing environments[END_REF]. To store data in the cloud network, we can use cloud storage. As a result, the cloud will require sufficient storage space as well as sufficient speed to load data simultaneously. The cloud era is arrived! It's a game-changing invention that combines public, private, and business process outsourcing capabilities. Scalability, elasticity, and flexibility are all advantages of cloud-based services. User groups and cloud service providers alike are concerned about data security and privacy [START_REF] Younis | Secure cloud computing for critical infrastructure: a survey[END_REF] in cloud computing. In the context of cloud computing, sensitive information covers data from a wide range of various fields and specialties [START_REF] Yang | Cloud computing research and security issues[END_REF]. As a result of the recent growth of new cloud technologies, privacy and data protection requirements have evolved to safeguard individuals against monitoring and database exposure. The study on data security and privacy in cloud computing systems is summarized in this publication. The remaining sections of this work are organized as follows. The related works is presented in section II.

We describe the cloud computing in section III cloud data storage in section IV. In section V, we present the security and privacy threats in cloud data storage. We are widely discussing the possible solutions for security and privacy threat in cloud data storage in section VI. We present benefits of cloud computing in sections VII. We conclude this paper in section VIII.

In section IX, we present future work of cloud computing. This paper gives an organizational framework in figure 1 to clearly depict the general structure.

II. RELATED WORKS

Any hosted service offered over the internet is referred to as cloud computing. Servers, databases, software, analytics, and other computing tasks that may be operated over the cloud are frequently included in these services [START_REF] Aguiar | An overview of issues and recent developments in cloud computing and storage security[END_REF]. The act of operating workloads within clouds is known as cloud computing. IT settings in which scalable resources are abstracted, pooled, and shared across networks.

In recent years, cloud computing privacy and security issues have been a popular topic [START_REF] Wei | Security and privacy for storage and computation in cloud computing[END_REF]. Data privacy, data protection, data availability, data location, and secure transmission are the most pressing concerns in cloud data security. Threats, data loss, service disruption, outside malicious assaults, and multitenancy difficulties are among the security challenges in the cloud [START_REF] Behl | Emerging security challenges in cloud computing: an insight to cloud security challenges and their mitigation[END_REF]. Users of this technology outsource their data to a cloud provider's server located outside of their premises [START_REF] Zhou | Efficient and secure data storage operations for mobile cloud computing[END_REF]. Memory, processor, bandwidth, and storage are also visible and accessible via the Internet by a client. By focusing on privacy protection, data segregation, and cloud security, Chen et al. [START_REF] Chen | Data security and privacy protection issues in cloud computing[END_REF] investigated privacy and data security challenges in cloud computing. Data security issues are primarily at SPI (SaaS, PaaS, and IaaS) level and the major challenge in cloud computing is data sharing.

This paradigm shift that comes with cloud computing usage is increasingly causing security and privacy concerns about aspects of cloud computing such multi-tenancy, trust, loss of control, and accountability [START_REF] Pearson | Privacy, security and trust in cloud computing[END_REF]. Before consumers and businesses use cloud computing, users' security concerns must be addressed in order for the cloud environment to be trusted. The trustworthy environment is the basic prerequisite to win confidence of users to adopt such a technology. The assessment of cloud computing hazards was examined by Latif et al. [START_REF] Latif | Cloud computing risk assessment: a systematic literature review[END_REF]. In other research, cloud infrastructures are combined with unique services aimed at specific businesses. To put it another way, the cloud is designed to provide specific services to clients, such as cloud computing for manufacturing or cloud computing for health care [START_REF] Jemal | Mobile cloud computing in healthcare system[END_REF]. Shynu et al. [START_REF] Shynu | A comprehensive survey and analysis on access control schemes in cloud environment[END_REF] explored several ways of secret communication, such as the secret channel, side channel attack, and fuzzy technology, addressed secret communication technology in relation to application situations, and demonstrated its benefits and drawbacks. Lo'ai et al. [START_REF] Lo'ai | Cloudlet-based mobile cloud computing for healthcare applications[END_REF] presented a mobile cloud computing concept that may be applied to a wide range of applications. The proposed architecture can be used to store and analyse data collected by various sensors and IoT devices. In restricted circumstances, the obtained data will be transferred to the mobile [START_REF] Yusuf Perwej | A Posteriori Perusal of Mobile Computing[END_REF] cloud model for analysis and making the best decision possible. Johanna et al. [START_REF] Ullrich | Network-Based Secret Communication in Clouds: A Survey[END_REF] looked into a variety of covert communication technologies, including hidden channels, bypass, and fuzzy technology. These approaches, on the other hand, are a type of non-mainstream technology and application, with a very limited application scope.

Cloud storage is similar to cloud computing in terms of accessible interfaces, scalability, and measurement resources because it is based on virtualization infrastructure. It consists of four layers [START_REF] Zhe | Study on data security policy based on cloud storage[END_REF], cloud storage supplies data access services including data storage, data computation, authentication, and access control. Due to the characteristics of cloud storage, data security and privacy issues are inevitably generated in this process.

Furthermore, the cloud provides the required administration and control capabilities to support (regulatory) governance [START_REF] Al-Mushayt | Electronic-Government in Saudi Arabia; a Positive Revolution in the Peninsula[END_REF] rules while also meeting the needs of multinational corporations [START_REF] Oussous | Big data technologies: a survey[END_REF]. Zhang et al. [START_REF] Zhang | Searchable encryption for healthcare clouds: A survey[END_REF] provided a technical review of four SE systems, including searchable symmetric encryption (SSE), public key encryption with keyword search (PEK), attribute-based encryption with keyword search (ABK), and proxy re-encryption (PRES). Several SE technologies, including searchable symmetric encryption (SSE), public key encryption keyword search (PEKS), attribute-based encryption keyword search (ABKS), and proxy re-encryption keyword search, were summarised by Zhang et al [START_REF] Jie | Toward Efficient Multi-keyword Fuzzy Search over Encrypted Out sourced Data with Accuracy Improvement[END_REF]. (PRES).

They just provided a technical description of the searchable encryption paradigm, with no relevant algorithms or performance comparison studies. Yusuf Perwej et al. [START_REF] Perwej | The Hadoop Security in Big Data: A Technological Viewpoint and Analysis[END_REF] in this paper highlight the main Hadoop security, technological viewpoint and analysis that may affect big data. Moreover, big data [START_REF] Parwej | A Close-Up View About Spark in Big Data Jurisdiction[END_REF] can be advantageous as a base for the development of the future technologies that will transform the world as we see it, like the cloud computing, Internet of Things (IoT) [START_REF] Akhtar | The Internet of Nano Things (IoNT) Existing State and Future Prospects[END_REF], or ondemand services, and Blockchain [START_REF] Perwej | A Pervasive Review of Blockchain Technology and Its Potential Applications[END_REF]. Edemacu et al. [START_REF] Edemacu | Privacy provision in collaborative Ehealth with attribute-based encryption: Survey, challenges and future directions[END_REF] examined and analysed the security, revocation ability, and efficiency of various attribute-based cooperative electronic health encryption methods. The privacy protection technology mentioned in this study, on the other hand, is relatively simple. Yusuf Perwej and colleagues take a quick look at the technical components of IoT security. Because when only two instruments were combined in the field of medical care, security was a major concern [START_REF] Perwej | The Internet-of-Things (IoT) Security: A Technological Perspective and Review[END_REF]. Tara et. al [START_REF] Salman | Security Services Using Blockchains: A State-of-the-Art Survey[END_REF] investigated several security service methods based on Blockchain, such as authentication, confidentiality, access control list, resource sources and integrity assurance, and discussed the challenges of security services.

A Blockchain [START_REF] Perwej | A Technological Perspective of Blockchain Security[END_REF] controller, cloud server, and authentication server (AS) are used to establish a cloud-based software defined network (SDN). To obtain the secret key, researchers recommend that all users register with the AS [START_REF] Cha | Blockchain-empowered cloud architecture based on secret sharing for smart city[END_REF]. Nikhat Akhtar at. al. [START_REF] Akhtar | A Holistic Analysis of Medical Internet of Things (MIoT)[END_REF] presents a comprehensive literature review of recent contributions focused on the Medical Internet of Things (MIoT). Medical Internet of Things-based healthcare services are expected to improve the user's quality of life, lower prices using clouds. In this publication, Jeffrey and colleagues [START_REF] Kimmell At | Recurrent Neural Networks Based Online Behavioural Malware Detection Techniques for Cloud Infrastructure[END_REF] investigate the effectiveness of deep learning algorithms based on Recurrent Neural Networks (RNNs) [START_REF] Perwej | Recurrent Neural Network Method in Arabic Words Recognition System[END_REF] for identifying malware in cloud Virtual Machines (VMs).

We concentrate on two key RNN architectures:

LSTMs (Long Short-Term Memory RNNs) [START_REF] Perwej | The Bidirectional Long-Short-Term Memory Neural Network based Word Retrieval for Arabic Documents[END_REF] and Bidirectional RNNs (Bidirectional RNNs) (BIDIs).

Based on run-time fine-grained processes system metrics like as CPU, memory, and disk use, these models learn the behavior of malware over time. Bader et al. [START_REF] Bader Alouffi At | A Systematic Literature Review on Cloud Computing Security: Threats and Mitigation Strategies[END_REF] conduct a thorough literature review to assess existing research on cloud computing security, dangers, and problems. This systematic literature review examined the research studies published between 2010 and 2020 within the popular digital libraries.

III. Cloud Computing

This section delves deeper into cloud computing. The Internet of Things (IoT) [START_REF] Perwej | The Internet of Things (IoT) and its Application Domains[END_REF], or the interconnection of people, devices, and "things," is growing as the number of information detecting devices connected to the Internet grows. The cloud service provider platform [START_REF] Teing | Forensic investigation of P2P cloud storage services and backbone for IoT networks: BitTorrent sync as a case study[END_REF] generates and hosts an unprecedented volume of data. Many applications and services will be hosted in the cloud due to the cloud's high performance, scalability, and reliability. The word "cloud," often known as "cloud computing," refers to any type of remote data storage solution [START_REF] Ferrer | Towards the decentralized cloud[END_REF] shown in figure 2. To be clear, your data is saved on remote servers and may be accessed via the Internet, rather than on your hard discs or local memories. You can rent rather than buy your IT using cloud computing.

Companies prefer to access their compute capacity over the internet [START_REF] Parwej | An Empirical Analysis of Web of Things (WoT)[END_REF], or the cloud, and pay for it as they use it, rather than investing extensively in databases, software, and hardware. Servers, storage, databases, networking, software, analytics, and business intelligence are now among the cloud services available. Cloud computing enables businesses to develop, innovate, and support business IT solutions with the speed, scalability, and flexibility that they require. There has been a substantial growth in cloud computing usage over the last several years as firms increasingly [START_REF] Rao Poranki | Integration of SCM and ERP for Competitive Advantage[END_REF] appreciate the cost savings, easy scalability, and work flexibility afforded by cloud. The global market for cloud-based services is expected to grow to $436 billion by 2024, up from $326 billion in 2020, with over 64 percent of businesses [START_REF] Rao Poranki | The buying Attitudes of Consumers of Cosmetic Products in Saudi Arabia[END_REF] adopting the cloud in some way.

Cloud computing saves businesses money on both hardware and software upkeep. By ensuring that our data is always available, an internet cloud architecture improves organization productivity and efficiency.

Public Cloud

In a public cloud, the cloud provider's whole computing infrastructure is housed on its premises, while the customer receives services via the internet.

Customers don't have to worry about maintaining their own IT, and they can easily add more users or computer power as needed. Multiple tenants share the cloud provider's IT infrastructure in this scenario.

Typically, the public cloud is highly [START_REF] Cao | Privacy-Preserving Multi-Keyword Ranked Search over Encrypted Cloud Data[END_REF] segregated to prevent cloud service overlap among different enterprises and to ensure each business's privacy and security. The public cloud's scalability is one of its most appealing features. Furthermore, most public clouds operate on a pay-as-you-go basis, meaning that users only pay for the cloud services that they use.

Edge Cloud

To lower processing costs and provide more lowlatency experiences for consumers, edge clouds decentralize computing power to clients and devices at the network edge. Edge cloud [START_REF] Abbas | Mobile edge computing: A survey[END_REF] will be a one-ofa-kind ecosystem of open and interconnected data centers, with data center operators and carrier alliances allowing it to reach critical mass Depending on the QoE objectives and resource requirements for a given application, the edge cloud can be located in any number of network locations. The location of the Edge cloud will vary depending on the perspective of an end-user, network operator, or application provider.

Private Cloud

A private cloud is a cloud that is only used by one company. It could be hosted on the organization's premises or in the data center of the cloud provider [START_REF] Chilipirea | A Comparison of Private Cloud Systems[END_REF]. The maximum level of protection and control is provided by a private cloud. This private cloud is exclusively available to customers of a single firm or group of companies, and the [START_REF] Cao | Privacy-Preserving Multi-Keyword Ranked Search over Encrypted Cloud Data[END_REF] organization has the freedom to build the private cloud to meet its specific needs. Administrative control, privacy, and security are all advantages of private clouds for business owners. Private clouds are often surrounded by highsecurity firewalls, with only approved users permitted access. For businesses that deal with sensitive information or that have strict regulatory requirements, using a private cloud enables them to easily make any configuration modifications that are relevant to their line of business.

Multi Cloud

Enterprises are attempting to de-risk themselves by putting various workloads in different clouds, hence a multi cloud strategy is the preferred model nowadays.

The usage of multiple cloud computing and storage [START_REF] Chase | Joint optimization of resource provisioning in cloud computing[END_REF] devices in a single architecture distinguishes hybrid cloud from multi cloud. Some organizations also prefer multiple clouds, as each cloud may offer a different technology capability. Businesses may personalize and compartmentalize their cloud network with multi cloud. The community cloud is scalable and versatile since it is generally compatible with all users and may be modified to suit their needs. [START_REF] Perwej | An Evaluation of Deep Learning Miniature Concerning in Soft Computing[END_REF], chatbots, Blockchain [START_REF] Perwej | Blockchain and its Influence on Market[END_REF], and the Internet of Things (IoT) [START_REF] Akhtar | The Internet of Nano Things (IoNT) Existing State and Future Prospects[END_REF].

The right PaaS offering also should include solutions for analysts, end users, and professional IT administrators, including big data analytics [START_REF] Yusuf Perwej | An Extensive Investigate the MapReduce Technology[END_REF],

content management, database management, systems management, and security.

Security as a Service (SECaaS)

The Security as a Service (SECaaS) is a service given by a managed security services provider that allows businesses to free up security resources by having the service provider take full responsibility for security.

Because it enables secure access to apps and services regardless of where they are hosted or when users connect, security as a service has become a key business enabler in the increasingly cloud and mobile world. SECaaS solutions can be scaled up or down as required and are provided on demand where and when you need them. The test environment as a service paradigm, which is an on-demand test environment, allows businesses to test their software or apps using only a web browser.

Clients save money on the deployment of test infrastructure for testing, as well as the tools needed

Disaster Recovery as a Service (DRaaS)

Disaster recovery as a service, or DRaaS, is the replication of physical or virtual servers hosted by a third party to offer failover in the case of a man-made or natural disaster. DRaaS can be especially useful to organizations that lack the necessary expertise to provision, configure, and test an effective disaster recovery plan. The goal of DRaaS is to achieve a quick recovery point [START_REF] Wood | Disaster recovery as a cloud service: Economic benefits & deployment challenges[END_REF]. This means that the data will be restored as closely as feasible to its current "now" state. Typical recuperation time goals are 4 hours or less, and equipment that are geographically located in a different place will be brought up.

File Storage

The file storage method preserves data in a hierarchical file and folder structure that is familiar to most of us. It is often used with network attached storage and personal computer storage discs (NAS).

Regardless of whether the data is stored in the storage system or on the client, the hierarchy makes it easier and more natural to search and retrieve files when needed [START_REF] Cao | Privacy preserving Multi keyword Ranked Search over Encrypted Cloud Data[END_REF]. Development platforms, home folders, and repositories for video, audio, and other data all need file storage. The primary disadvantages of file storage, if we plan for your data to grow, there is a certain point at which the hierarchy and permissions will become complex enough to slow the system significantly.

V

Privacy of Cloud Data

The data on the cloud is distributed all over the world. The user has no knowledge of the location of data and has no control over the physical access mechanisms to that data. Many countries, cultures, and jurisdictions have vastly different ideas about privacy. When an investigation happens, there is also the issue of whose jurisdiction the data belongs under.

There are several databases and applications in a distributed system. Governments [START_REF] Al-Mushayt | Electronic-Government in Saudi Arabia; a Positive Revolution in the Peninsula[END_REF] should have at least a rudimentary policy in place to deal with such circumstances.

Administrative Entrance

Administrative access in cloud computing is done over the internet, which raises the danger. It is very important to control administrative access to data and monitor the access to maintain protocols. 126

Access Control

Data security must be given extra attention when data is outsourced to the cloud, which is untrustworthy since it is in a domain where security is not regulated by the data owner. When more than one entity wants to exchange data, a method must be in place to limit who has access to that data. The literature [START_REF] Nie | The Research of Information Security for The Education Cloud Platform Based on AppScan Technology[END_REF] has discussed a variety of strategies. Those techniques were proposed to keep data content confidential and keep unauthorized entity from accessing and disclosing the data by using access control while permitting many authorized entities to share those data.

Data Breaches

A data breach happens when an unauthorized person or group of persons accesses protected, secure, sensitive, or confidential data. Users and organizations in a cloud environment all have access to the same data. Any breach of this [START_REF] Zhou | Efficient and secure data storage operations for mobile cloud computing[END_REF] cloud environment would open the door to all users' and businesses' data. The attacker's primary aim is usually not the user, although the user is ultimately affected. Because of multi-tenancy, customers using different applications on virtual machines could share the same database and any corruption event that happens to it is going to affect others sharing the same database [START_REF] Farooqi At | The notorious nine: top cloud computing security challenges in 2017[END_REF].

APIs and Storage Gateways

To help them migrate their data to the cloud, several businesses employ cloud storage APIs or storage gateways. Between the [START_REF] Zhang | A survey on cloud interoperability: taxonomies standards and practice[END_REF] user and the storage provider, these products serve as a go-between. They may make it easier for your employees to access and manage data in your cloud, but an insecure API or gateway could endanger your data. If you want or need to utilize a storage API or gateway, ensure sure it has a good reputation for security.

Sharing of Data

The utilisation of data is rising as a result of data sharing. The data owners can grant one party access to the data, and that party can then share the data with others. This sharing can lead to major issues, such as data leaks to an unauthorized people.

Therefore, during the data sharing especially when shared with a third party, the data owners need to consider whether the third party continues to maintain the original protection measures and usage restriction.

Destruction of Data

When data is no longer needed, it is expected to be totally deleted. The data destroyed may still persist and be restored due to the physical features of the storage medium. This could lead to the disclosure of sensitive information.

Keeping Application Integrations Up to Date

Enterprise cloud apps of today are built on cuttingedge, internet-optimized architectures. Vendors can design their services and accompanying interfaces using the contemporary web technologies that underpin these apps. Unfortunately for the IT professionals, that also means that every new vendor may require a new approach when it comes to integration, particularly concerning user authentication and management.

Data Location

Cloud providers have a slew of data centres strewn over the globe. Users of cloud computing need to know where their data is stored, hence data location is a problem. Depending on the jurisdiction, some countries compel corporations to retain their data in their country. Also, there are regulations in some countries where the company can store their data.

Also, the data location matters when the user data is stored in a location that is prone to wars and disasters.

Latency

Traffic congestion can cause delays in data transmission to and from the cloud, especially when using shared public internet connections. Companies, on the other hand, can reduce latency by increasing connection bandwidth.

Distributed Denial of Service (DDoS) Attacks

DDoS attacks aren't new, but they can be particularly debilitating when directed against our company's public cloud. DDoS attacks have a significant impact on the availability and security of key infrastructure in the cloud [START_REF] Zargar | A Survey of Defense Mechanisms Against Distributed Denial of Service (DDoS) Flooding Attacks[END_REF]. This form of assault can be crippling, causing systems to slow down or shut down. DDoS attacks also consume significant amounts of processing power a bill that the cloud customer (you) will have to pay.

Multi Tenancy

The term "multi-tenancy" refers to the sharing of physical equipment and virtualized resources among numerous users. An attacker could be on the same physical machine as the target if this arrangement is used. Multi-tenancy characteristics are used by cloud providers to create infrastructures that can easily scale to meet customers' needs; nevertheless, because resources are shared, it may be easier for an attacker to obtain access to the target's data.

Virtual Machine Rollback

Rolling back a virtual computer to its earlier state is a process. This procedure has additional security risks because it gives the user more flexibility. For example, a virtual machine could be rolled back to a previous vulnerable state that has not been repaired [START_REF] Hashizume | An analysis of security issues for cloud computing[END_REF] or to an out-dated security policy or old configuration. In another example, a user could be deactivated in a previous state but still have access when the virtual machine's owner rolls back. according to the report [START_REF] Treseangrat | Analysis of UDP DDoS cyber Flood Attack and Defence Mechanism on Windows Serevr 2012 and Linux Ubuntu 13[END_REF]. When a denial of service assault is launched against a client's cloud service, the service may be harmed rather than shut down, in which case the customer will be billed by his cloud service for any resources utilized during the attack.

Cloud computing, on the other hand, has increased their popularity [START_REF] Kiss | Denial of Service attack Detection in case of Tennessee Eastman challenge process[END_REF]. These assaults consume a lot of computing power and slow down cloud availability. The worst part is that there's nothing you can do but sit and wait once it happens.

Regulatory Compliance

Certain industries, such as healthcare and finance, have to comply with strict data privacy and archival regulations, which may prevent companies from using cloud storage for certain types of files, such as medical and investment records. Choose a cloud storage provider that enables compliance with any industry rules that affect your business if at all possible.

Loss of Control

Another potential security breach that can occur when customers' data, apps, and resources are housed on the cloud provider's premises is loss of control. As the users do not have explicit control over their data, this makes it possible for cloud providers to perform data mining over the users' data, which can lead to security issues. Furthermore, because cloud providers store data in multiple data centers, customers cannot be certain that their data is truly deleted when they remove it. This could lead to data being misused that hasn't been removed. In these types of situations where the consumers lose control over their data, they see the cloud provider as a black-box where they cannot directly monitor the resources transparently.

Cryptojacking

Cryptojacking is a sort of cyber-attack in which a hacker uses a target's processing capacity to mine crypto money on his or her own behalf. Individual customers, large institutions, and even industrial control systems can all be targets of cryptojacking.

Cryptojacking virus slows down infected machines since the mining process takes precedence over other legitimate tasks [START_REF] Rydstedt | Busting frame busting: a study of clickjacking vulnerabilities at popular sites[END_REF]. Cryptojacking has become a serious global problem, with cybercriminals gaining unauthorized entry to computer systems to make money with minimal risk and effort. Hackers are inventing new techniques to steal computer resources and mine for crypto currency, which is known as cryptojacking.

Accidental Exposure of Credentials

In their phishing attempts, phishers frequently leverage cloud apps and environments as a pretext. As a result, cloud providers genuine trust in their clients by ensuring them that their operations are certified to meet organizational safeguards and standards.

Cross Virtual Machine (VM) Side-Channel

Attacks

The attacker must be in a different virtual computer on the same physical hardware as the victim to carry out this attack. The attacker and the victim are both using the same CPU and cache in this attack. When the attacker switches the virtual machine execution of the victim, the attacker can learn about the victim's

behaviour. An example of a virtual machine sidechannel attack and how an attacker can deduce information about a victim can be found here. The timing side channel attack is one kind of virtual machine side channel attacks. This attack is based on calculating how long certain computations take. This attack has the potential to leak sensitive information, such as the identity of the person performing the calculation or information from the cloud provider itself. Due to privacy concerns, the owner of the virtual machine can check other [START_REF] Hlavacs | Energy consumption side-channel attack at virtual machines in a cloud[END_REF] virtual machines, making this attack difficult to detect.

Misconfigured Cloud Storage

For cybercriminals, cloud storage is a valuable supply of stolen data. Despite the high stakes, businesses continue to make the error of misconfiguring cloud storage, which has resulted in significant losses for

Snooping

Without security precautions in place, files in the cloud are among the most vulnerable to being hacked.

The fact that they are saved and transmitted across the internet adds to the danger. Snooping in network security compromises the privacy of a variety of data that should be kept private on a computer network.

Lack of Backup Services

One of the most common concerns about storage systems is that they lack automatic backup capabilities. They expect you to back up the data you put in the cloud instead. This problem does not affect all storage providers; in fact, some will automatically backup your data for you. Those that do not provide backups, on the other hand, do not provide a safety net in the event of a sudden data loss.

Weak Authentication and Identity Management

Data breaches in businesses are caused by a lack of adequate authentication and identity management.

Businesses sometimes struggle with identity management because they try to assign access to each user based on their job function [100]. Enterprise cyber-security might be endangered by poor identity management. For example, cyber-criminals gained access to 80 million records containing personal and medical information as a result of the Anthem Inc. data breach. Anthem had neglected to implement multi-factor authentications hence this vulnerability was the result of stolen user credentials.

Trojan Horse

A Trojan horse is a programme that appears to be useful but is actually destructive to the host PC. A dangerous payload is concealed in some areas of this sort of malware that can exploit or damage the host system. Trojan horses can also be spyware because of their malicious actions such as the unauthorized collection of a user's data.

Data Breaches

A data breach occurs when sensitive, protected, or confidential information is copied, communicated, viewed, stolen, or exploited by someone who is not allowed to do so. As a result of the huge data held in the clouds, cloud providers are an attractive target for hackers. The severity of the attack is determined by the confidentiality of the information that will be disclosed. If the disclosed material is personal, such as health information, trade secrets, or intellectual property of a person or an organisation, the damage will be serious [101]. This will result in significant harm.

Synchronization Mechanisms Issues

In Another option is to utilise encryption appliances, which encrypt data as it leaves a private network and decode it when accessed by a trusted user. The encryption we use must be compatible with the capabilities of the application we're using and the cloud service provider we're utilising. Different mechanisms may have a considerable impact on the user experience, so the impact on end-user performance must also be addressed.

Formal Change Control Process

The [118] presented an asymmetric encryption technique.

Commutative encryption is employed on data several times in the proposed process, and the order of public/private keys used for encryption/decryption is irrelevant.

AI Tools and Auto Patching

Artificial intelligence, or AI, is also being used by cloud providers to help protect your data. This is critical, yet finding skilled security personnel to supervise data is difficult. Cloud providers, on the other hand, can use artificial intelligence to handle at least the initial level of security assessments. Built-in algorithms are used by these tools to look for and identify potential security flaws.

Encryption of Backups

Data backups in the cloud must be encrypted; otherwise, data encryption is worthless if the backups are not encrypted. If these backups are not safeguarded with adequate encryptions, any hacker can gain access to them. Data is not secure if backups are not encrypted. A reinforcement that hasn't been tested is a useless reinforcement. In the generation condition, a decoded reinforcement overcomes the security measures. Data should be protected throughout its entire existence.

6.12 Built-in firewalls Firewalls are used by cloud providers to protect your files as well. This technology works in the same way as a wall, keeping your data safe. Firewalls, which can be either hardware or software-based, apply rules to all network traffic. These rules are intended to filter out potentially harmful traffic and keep your data safe behind the firewall. This makes it more difficult for hackers to slip malware or viruses past the security measures used by your cloud service provider.

Hierarchical Attribute Set Based Encryption (HASBE)

Each user or data owner is maintained by a domain authority, which combines the properties of attribute set based encryption (ASBE) and hierarchical identity-based encryption (HIBE). The system can have five types of participants: the first is the data owner, the second is the user, the third is the domain authority, the fourth is the parent and trusted authority, and the fifth is the cloud service provider.

To build the hierarchy of system users, the scheme employs the delegation algorithm. [122]. This system inherited not just the scalability of a hierarchical structure, but also the flexibility and fine-grained access control that ASBE composite attributes require.

Encrypt Your Data

To begin, ensure sure your files are sent to a cloud service provider that encrypts data. We aim to make it as difficult for hackers to access your information as possible. The storing your images and files with a provider that relies on encryption will give hackers pause. They have an easier time stealing data that hasn't been scrambled.

Service Abuse

Attackers can utilise the cloud service to obtain extra data or ruin the interests of other users by abusing it.

Other users may misuse user information. In cloud X.

Figure 1

 1 Figure 1 The Organization of Research Paper Framework

Figure 2

 2 Figure 2 The Cloud Computing

3. 1 . 5

 15 Hybrid Cloud Hybrid clouds, as the name implies, are a mix of public and private clouds meant to work together seamlessly, transferring services and applications from one to the other. Hybrid cloud customers typically host business-critical apps on their own servers for increased protection and control, while storing secondary applications at the cloud [55] provider's location. With hybrid clouds, business owners can simply scale up their network infrastructure by leveraging the public cloud while keeping their data privacy, security, and access control in the private cloud. The hybrid cloud model is also preferable for hosting workloads that must meet compliance or data security standards. 3.1.6 Distributed Cloud Distributed cloud is a public cloud computing service that allows you to run public cloud infrastructure in multiple locations, including on premises, in the data centers of other cloud providers, and in third-party data centers or co-location centers, all while managing everything from a single control plane. According to a current trend, Gartner defines distributed cloud as the distribution of public cloud services to different physical locations, but the original public cloud provider is responsible for the services' operation, governance, updates, and evolution [56]. Distributed cloud speeds up worldwide service communication while also allowing for more responsive communications for any given region. Distributed cloud computing provides repeatability and dependability, as well as georeplication, which helps to save costs while also providing instantaneous fail-overs via remote replicas that may be reset in the event of a failure. Distributed cloud allows breaking complex problems and data into smaller pieces and has multiple computers which can be worked upon in parallel.

3. 1 . 7

 17 Community Cloud A community cloud allows a group of multiple organizations to access systems and services in order to communicate information between the organization and a specific community. The goal of this concept is to allow numerous customers to collaborate on community-owned projects and apps when a centralized cloud infrastructure is required. In other words, Community Cloud is a distributed infrastructure that integrates the services given by many types of cloud solutions to answer the specific concerns of business sectors. With hybrid clouds, business owners can simply scale up their network infrastructure by leveraging the public cloud while keeping their data privacy, security, and access control in the private cloud. The hybrid cloud model is also preferable for hosting workloads that must meet compliance or data security standards. Because of the exclusive user group, organizations do not have to be concerned about the security problems associated with public cloud. It is owned, managed, and operated by one or more organizations in the community, a third party, or a combination of them.

3. 2

 2 Services of Cloud Computing Cloud services are now available to satisfy almost any IT requirement. It's more about finding the proper solution to suit your business and personal needs than there is a one-size-fits-all strategy to cloud. Each service model represents a different component of the cloud stack with its own set of responsibilities for you and the service provider [58].

Figure 3

 3 Figure 3 Types of Cloud Computing Service Models

3

 3

  for testing and maintenance. Clients benefit from TEaaS since it reduces the costs of physical infrastructure, testing tools, IT support staff maintenance, testing resources, and so on. Concerns concerning cyber security in a cloud-based test environment, on the other hand, are a major impediment to the worldwide test environment as a service market's growth. 3.2.10 Communication as a Service (CaaS) The "Communications" is represented by the C in CaaS. This means we'll use a single vendor to handle all of your communication needs. This cover, among other things, phone over IP, instant messaging, collaboration, and video conferencing. The supplier is in charge of all hardware and software administration in this situation. They usually charge on an ondemand basis so you'll always only pay for what you need. This means that this model is flexible and will grow as your need for communication grows.3.2.11 Artificial Intelligence as a Service (AIaaS) Artificial intelligence as a service (AIaaS) is a thirdparty AI outsourcing service. AIaaS refers to AI platforms that allow businesses to implement and grow AI approaches for a fraction of the expense of a full-fledged AI department [70]. The term "service" in AIaaS refers not only to the cloud-based software delivery model, but also to the extent to which the vendor is involved in the process. The nine yards of AI [71] are delivered as a unified platform by IT companies delivering AIaaS, from problem conceptualization to keeping the model on track and expanding to new use cases, through constructing the model, deploying the solution in production, and sustaining it in real-world settings. AI cloud offerings including Amazon Machine Learning, Microsoft Cognitive Services and Google Cloud Machine Learning [72] can help organizations what might be possible with their data. AIaaS solutions also provide more scalability, flexibility, and also use.

3. 2 .

 2 12 Desktop as a Service (DaaS) Desktop as a Service (DaaS) is a sort of offering that provides virtual desktops to end customers. It is extremely popular in the remote working environment. Virtual desktops promise robust security, as all information is stored on the server, and not on individual machines or laptops. The service provider is responsible for all data management, backup, and storage [73]. DaaS runs across a range of operating systems and device kinds, which promotes the trend of employees bringing their own devices to work and relieves the cloud service provider of the responsibility of supporting the desktop on all of those devices. Desktop as a Service (DaaS) has a number of distinct advantages over the traditional desktop paradigm. Deploying or decommissioning active end users with DaaS is much faster and less expensive. 3.2.13 Network-as-a-Service (NaaS) Network-as-a-Service enables us to gain direct and secure access to network infrastructure. Custom routing protocols can be deployed using NaaS. To provide network services to customers, NaaS employs virtualized network infrastructure. The network resources must be maintained and managed by the NaaS provider. Having a provider work for a customer reduces the customer's workload. Furthermore, NaaS provides network as a service. NaaS is also based on pay-per-use model.

5. 6 5 . 7

 657 Cloud Data Control and Loss of TransparencyConsumers are ignorant of the data loss that is out of their control due to the cloud service provider's storage of data. The user's access to confidential data stored in the cloud could be compromised[START_REF] Li | Identity based authentication for cloud computing[END_REF]. The user has no idea where, how, or when the data is handled due to a lack of transparency. To fix this issue, the user must understand what happens to the data. Cloud service providers are technically able to do data mining as well as data abstraction need techniques to analyse user data. As a result, customers can store and analyze data on the cloud with the help of a cloud service provider. The lack of transparency might also result in the loss of a significant amount of data. Service Hijacking Phishing, fraud, and software exploitation flaws are the most common ways to steal an account's credentials and passwords, and they still work.Credentials and passwords can be reused, which increases the impact of such assaults. All the transactions achieve network traffic between user and cloud service provider. When an attacker acquires access to a user's credentials, he can listen in on the user's transactions and personal information[START_REF] Priya | jungwoo ryoo, hyoungshick kim "addressing security challenges in cloud computing a pattern-based approach[END_REF].5.8 Denial of ServiceBecause of the crucial services they provide, certain businesses require their systems to be available at all times. The cloud services provider makes resources available to a large number of clients. If an attacker uses all available resources, others cannot use those resources, which leads to denial of service and could slow accessing those resources. Customers that use cloud services and are victimized by the botnet could also seek to disrupt the availability of other providers.5.9 Transmission of DataData is transmitted from one location to another in a cloud system. Although encryption is used to protect data during transmission, most data is not encrypted during processing, and it must be unencrypted in order to be processed for any purpose. An attacker can find a place between communication paths. The attacker can change the communication. 127 5.10 Lack of Trust and Dependence on Cloud Provider The availability of cloud services is a key issue. Due to a shortage of funds, the cloud service provider has ceased to provide services, and users may experience difficulties accessing their data. Some widely used cloud service provider, for instance Google Drive does not provide any contract between the user and cloud service provider.

5. 20

 20 Denial of Service (DoS) Attacks Denials of service assaults are an old approach in the internet world, but they still pose a concern. Before operations are clogged by hundreds of thousands or millions of automated requests for service, they must be discovered and screened out. However, attackers have devised increasingly sophisticated and dispersed methods of carrying out the attack, making it more difficult to distinguish between malicious actors and legitimate users in a modern-day botnet attack. For cloud customers, "experiencing a denial-of-service attack is like being caught in rush-hour traffic gridlock: there's no way to get to your destination, and nothing you can do about it except sit and wait,"

  Employees have become accustomed to receiving emails with links that may ask them to confirm their account credentials before gaining access to a particular document or website, thanks to the growing use of cloud-based email (G-Suite, Microsoft 365, etc.) and document sharing services (Google Drive, Dropbox, OneDrive). This makes it easy for cybercriminals to learn an employee's credentials for cloud services. As a result, 46 percent of firms are concerned about unintentional exposure of cloud credentials, which could endanger the privacy and security of their cloud-based data and other resources. 5.25 Trust Chain in Clouds By ensuring on cloud providers, trust plays a key function in recruiting more customers. Cloud users rely on cloud providers to employ trust mechanisms as an alternative to offering them visible control over their data and cloud resources due to a loss of control.

  many businesses. According to a report by Symantec, nearly 70 million records were stolen or leaked in 2018 due to misconfigured cloud storage buckets. The survey also noted the advent of a number of technologies that allow attackers to discover and target misconfigured cloud storage. Cloud storage misconfiguration can quickly escalate into a major cloud security breach for an organization and its customers.

  cloud is fast and secure for time-sensitive data if enterprises have a formal control process modification. If the organisation does not have a proper change process control in place during routine upgrades, the servers will fall down and no one will be able to access the data. And if the data is time sensitive than this cloud which do not have formal change process control, they are not safe for tie sensitive data. Organizations that execute changes and setup in a specially appointed way will probably encounter huge downtime in their condition. Lack of foresight and a lack of progress management are the primary causes of system outages. If the data you're sending to the cloud is time-sensitive, we'll need to work with a vendor who follows a structured change management process, avoiding the inherent risk of unplanned modifications.6.4 Attribute Based EncryptionFor the first time, Sahai et al. presented fuzzy identity-based encryption [111], which is the origin of attribute-based encryption (ABE). In contrast to identity-based encryption, attribute-based encryption replaces identity with a set of attributes, and only users whose attribute set fits the access policy can access the encrypted material. The ABE algorithm is divided into four sections. The setup phase, also known as the system initialization phase, is where relevant security parameters are entered and associated public parameters (PK) and master keys (MK) are generated. The data owner provides their own attributes to the system in the second phase of the KeyGen step, namely the key generation stage, to acquire the private key associated with the attributes. The data owner encrypts the data using his or her public key, obtains the cypher text (CT), and delivers it to the receiver or to the public cloud in the third part encryption phase. In the last part decryption phase, decryption users get cipher text, decryption with their own private key SK. In data sharing applications, attribute-based encryption promises to give fine-grained access control over encrypted files, allowing the data owner to select who can access the protected data. 6.5 Access Control in Cloud Computing In cloud computing, access control is a critical security method for ensuring data security. It ensures that only authorised users have access to the cloudbased data they've requested. In cloud computing, there are a variety of security techniques that allow for adequate access management. On separate network and cloud tiers, intrusion detection systems, firewalls, and responsibility separation could be deployed. Only restricted content is allowed to enter over the cloud network due to the firewall. Typically, a firewall is configured according to the user's established security policies. 6.6 Homomorphic Encryption Encryption is commonly used to protect data secrecy. Rivest et al. [112] devised a type of encryption system called homomorphic encryption. It assures that the results of the cypher text algebraic operation are compatible with the clear operation following encryption results, and it also eliminates the necessity to decrypt the data throughout the procedure. The application of this technology has the potential to solve the problem of data and data operations secrecy in the cloud. Gentry et. al. firstly proposed the fully homomorphic encryption method [113], which can do any operation that can be performed in clear text without decrypting. It's a significant step forward in homomorphic encryption technology. In figure 4 shown, the easier for us to understand how homomorphic encryption works in cloud. The data owner protects the data and sends it to the cloud server using homomorphic encryption. With the associated private keys, authorised users can decrypt the cypher text. User 2 just needs to send the functions corresponding to the operations to the cloud server if he wants to do certain specific operations on cypher text. The servers get operand and perform the operation without decrypt the cipher text and return the encrypted result to user second. Homomorphic encryption effectively protects the security of outsourced data.

Figure 4 Homomorphic Encryption 6 . 7

 467 Figure 4 Homomorphic Encryption

Figure 5

 5 Figure 5 Multi-Authority Attribute Based Encryption

  Rachel et. al. [119] proposed a hierarchical encryption based on attribute set, which extended the user hierarchy to ASBE. This system inherited flexibility and fine-grained access control in enabling composite attributes, as well as scalability of hierarchical structure. Wan et al. [120] proposed the HASBE system, which expanded attribute set encryption based on a user hierarchical structure's cypher text strategy while inheriting ASBE's fine-grained access control. Data owners and service providers are rarely in the same trusted domain in cloud computing. Further, [121] proposed a secure and efficient cloud computing data collaboration scheme based on hierarchical attribute encryption. This approach provided partial decryption structure and produced partial signatures by outsourcing signature calculation when users decrypted cypher text. A hierarchical attribute-setbased encryption was proposed by Gokuldev et al.

6. 14

 14 Redundancy (ultra-backed-up data)What if there's a hardware breakdown or a power outage? Will you be able to access your data in the event of a natural disaster or a large-scale outage at your cloud provider. Because the majority of the world's largest cloud providers use redundancy. This means that they copy your data several times and store them on many different data centers. You can access your files from a backup server if one machine breaks down.6.15 Hybrid TechniqueFor data secrecy and integrity, a hybrid solution[123] is presented, which combines key sharing and authentication techniques. Using strong key sharing and authentication mechanisms, the user's connection to the cloud service provider can be made more secure. RSA public key algorithm can be used for secure distribution of the keys between the user and cloud service providers. A three-layered data security method is offered[124]. The first tier ensures the cloud user's authenticity through one-factor or twofactor authentications, the second layer encrypts the user's data for security and privacy, and the third layer ensures quick data recovery through a fast decryption procedure.6.16 Written Security Policies PlanThe security of the data will be guaranteed if the cloud service provider has a written security plan of policies. If the cloud service provider does not have a written security plan of policies, the cloud is not safe and the security of the data cannot be guaranteed because they do not have a written plan of security policies. This indicates that they are working on a data security programme. Organizations that have not formalized their security strategies cannot be trusted with your touchy corporate/ client information. Strategies shape the system and establishment and without security is just an idea in retrospect 6.17 Ranked Keyword Search Ranked keyword search refers to the system's feedback returns sorted by relevant parameters such keyword frequency, which improves the system's applicability and meets the real-world need for privacy protection in cloud computing. To safeguard privacy, Sun et al. [125] suggested a multi-keyword search technique based on similarity ranking. Based on cosine similarity, this approach developed a search index based on word frequency, and the vector space model can gain improved search result precision. A cypher text keyword ranking search technique was proposed by Cao et al. [126]. They use "coordinate matching" and "inner product similarity" to quantify the similarity, according to safe inner product computation. Wang et al. [127] suggested a ranked search symmetric encryption (RSSE) system with little information leakage. This technique also created a novel encryption primitive that employed one-to-many mappings to safeguard privacy and verify search results in order to search the encrypted file set. A multi keyword ranked search technique was developed to capture the correlation between data documents and search queries by creating a coordinate matching mechanism [128]. In addition, the scheme used the inner product similarity to quantitatively evaluate the related similarity measure. 6.18 Proper Usage of Administrative Privileges Administrative powers should be limited in cloud computing organisations, and administrative accounts should only be used when absolutely necessary. All administrator accounts should be inventoried using automated techniques, and each user with administrative access on laptops, desktops, and servers should be authorised by a senior executive. All administrator passwords should be complicated, containing a combination of digits, letters, and special characters, and should not contain dictionary words [129]. Before introducing any new devices in the networked systems, all default passwords for operating systems, applications, firewalls, routers, wireless access points, and other systems should be changed. Passwords for service accounts should be changed on a regular basis and should be long and difficult to guess. Passwords should be encrypted or hashed before being stored. Hashed passwords should follow the guidance supplied in NIST SP 800-132 or similar guidance. Administrator must use unique and different passwords for their administrative and nonadministrative accounts. This objective can be accomplished by enforcing policies and increasing user knowledge. 6.19 Data Concealment Data hiding could potentially be utilised in the cloud to maintain data secrecy. Delettre et al. [130] proposed a database security concealing concept. Data concealing techniques combine genuine data with visual false data to distort the volume of the real data. Authorized users, on the other hand, can quickly distinguish between bogus and authentic data. Data concealing techniques boost the overall volume of genuine data while improving the security of personal information. The goal of data hiding is to protect sensitive information from harmful users and attackers. Watermarking [131] can be used as a key to unlock the real data. Only the authorized users have key of watermarking, so the authentication of users is the key to ensure the true data to be accessible for right users.6.20 Key Management StrategyThis refers to the way you manage your encryption keys. There are already a number of cloud services that provide key management solutions, many of which are part of a broader cloud service suite. The drawback with these options is that you're still giving someone else power over your data. An approach that keeps the keys under your organization's control, either through a key management solution or an encryption appliance, may provide better risk mitigation, especially in jurisdictions that have strict data localization laws.6.21 Multi-TenantThe core of cloud computing is virtualization technology, which paved the way for multi-tenant cloud computing. Multi-tenant software is frequently installed on the same physical host, which might cause problems for other users, such as channel attacks. Because the virtual machine can be dynamically transferred based on performance and requirements, and access permissions can be changed, ensuring privacy protection is critical. Landuyt et al.[132] suggested a multi-tenant and flexible access control strategy that ensured strong data isolation for businesses in cloud stores. It can turn an employee into an unauthorised user with no access to others and ensure that cloud data is properly isolatedNgo et al. [133] developed a new multi-tenant access control approach based on the safety obligation separation principle. CSP may manage the security issues of cloud tenants such as addition, deletion, and management under this approach. Gonzales et. al.[134] proposed a service-oriented multi-tenant access control model that can meet the requirements of the users and automatic generate related roles in the cloud environment. 6.22 Strategies for Secure Transition to the Cloud Protecting what matters is the most important aspect of data security. Solutions that allow businesses to reliably migrate to the cloud while retaining most of their existing infrastructure and investments provide considerable benefits. By securing data inside the operating environment while setting security policies and keeping control through a centralized management interface, vormetric data security addresses the enterprise cloud security conundrum. Vormetric collaborates with cloud providers and businesses to protect data, regardless of whether it's [135] stored in physical, virtual, or cloud environments. Organizations can establish access policies and achieve complete control of data in private, public, or hybrid cloud environments. Only vormetric provides a complete platform for protecting both local data within the internal environment and cloud-based data within infrastructure or hosted application sites when moving to the cloud [136]. The combination of structured and unstructured data protection, as well as fine-grained user and process access controls that guard against unauthorized access to protected data. Because it is installed atop the file system and logical storage volume levels, the vormetric data security transparently secures data without needing application or database redesign or recoding,[137]and is transparent to users, applications, and cloud storage. In IaaS environments such as Amazon EC2, IBM Smart Cloud, Savvis, Rackspace, etc., enterprises can spin up instances to encrypt structured and unstructured data without rearchitecting or recoding applications. 6.23 Third-Party Security Testing Outside security organizations should be hired by the cloud provider to test their servers and software on a regular basis to ensure that they are safe from hackers, cybercriminals, and the newest malware and viruses. This outside testing boosts the odds that your cloud provider will have the defenses needed to keep your files away from hackers. 6.24 Reliability of Hard-Drive In the cloud environment, hard drives are now the most used storage medium. The core of cloud storage is the reliability of hard discs. Pinheiro et al. investigated the error rate of hard drives using historical hard-drive data [138]. They discovered that hard-drive error rates are not significantly related to temperature or frequency of usage, and that hard-

7. 12

 12 Economies of Scale Cloud computing saves money by taking advantage of economies of scale. According to a study by Booz Allen Hamilton, cloud computing could cut costs by 50 to 72 percent for a deployment of 1000 servers. Customers who use the cloud can save money by taking advantage of vendor economies of scale and reducing their investments in on-premises infrastructure.7.13 Multimedia Cloud ComputingUsers can now quickly access multimedia information through the internet at any time thanks to the invention of cloud computing. After subscribing, the user can easily store multimedia [147] content of any sort and size in the cloud. Because the calculation time for processing media data is longer in complicated hardware, the cloud can not only store but also process media material such as audio, video, and image. After processing, processed data can be simply retrieved from the cloud via a client without the need for complex hardware installation.7.14 OperationalTechnology will never be perfect, but some of it is simpler than others. This includes cloud computing infrastructure, which is often hosted on separate servers by a third-party vendor. So, when problems do arise, it's the vendor's job to promptly fix the problem instead of having on-site IT staffs spend time and resources file claims or updating servers. 7.15 Quality Control Few things are as damaging to a company's growth as poor quality and inconsistent reporting. All documents are stored in one place and in the same format in a cloud-based system. We can preserve data consistency, avoid human error, and have a clear record of any edits or updates if everyone has access to the same information. Managing information in silos, on the other hand, can result in employees saving different versions of documents by accident, resulting in confusion and diluted data.

7. 16

 16 Multi-SharingCloud computing allows several users to share architecture and other applications. Multiple users and apps can operate more efficiently and save money by using common infrastructure when using the cloud in a distributed and shared way [148].7.17 Automatic UpdatesUsers that use the cloud don't have to worry about keeping their software up to date. Instead of involving IT teams and forcing them to do a manual upgrade, cloud-based applications automatically refresh and update themselves.

7 .

 7 18 improved communication Having access to instant messaging, conference, and video conferencing options through cloud computing promotes staff communication and cooperation. They can collaborate on papers and projects together, resulting in greater cohesion and teamwork. This is made possible by data centralization and real-time cloud server updates. 7.19 Real-Time Insights Millions of data points exist in your business data that can be used to improve it. It can be difficult [149] to assess how your firm is doing and what route to take next if your data is concealed in silos of data, on local workstations, or in diverse forms. Moving your business systems to the cloud allows you to get better visibility over your business performance, in realtime, so that you can make informed decisions. 7.20 Processing Speed The practically infinite computational power accessible in the cloud allows you to reap the benefits of faster processing. Complex workloads that would normally take hours to accomplish on-premises are now completed in minutes. Websites will load faster, and video will render more quickly [150]. The possibilities are endless. When it comes to data crunching, processing speed is equally important. Using the cloud's near-limitless compute resources for services like big data and machine learning allows you to gain deep insights from your data much more quickly than traditional analytics. VIII. Conclusion Cloud computing is a novel means of delivering resources to users "as a service" over the internet. Cloud computing consumers no longer own the infrastructure that is completely controlled by these service providers, unlike traditional approaches that are based on hardware ownership where data is stored. You may sync your cloud storage service with your smartphone, tablet, or other mobile devices for convenient access while on the road once you've signed up for it and uploaded your files. Cloud computing is a computing model that enables ondemand network access to a pool of configurable computing resources, such as networks, services, storage, and applications, that can be quickly supplied and released with minimal administration effort or service provider contact. Cloud computing is a new concept that allows users to access scalable and virtualized resources, such as bandwidth, software, and hardware, on demand. Although it has gained a lot of attention in recent years, the issue of privacy and data security is one of the key roadblocks to cloud computing's progress. In this article, we looked at numerous significant security risks for cloud computing environments from various angles, as well as the solutions that all users and companies should be aware of when selecting whether or not to use the cloud. This work contributes to the discovery of a solution for the security and privacy issues in cloud data storage that have been identified in other techniques, as well as the development of a novel solution or approach to secure the cloud. IX. Future Work of Cloud Computing Because of the flexibility of cloud computing, users will access and share their software applications online and access information via remote server networks rather than relying on primary tools and information hosted on their personal computers in the future. Cloud computing privacy and data security issues are constantly one of the key study topics for researchers and developers to find appropriate solutions. From the standpoint of this paper, we recommend that you discover the best and most appropriate privacy and data security solutions for the cloud services you use. Compliance, physical security, cloud migration, transparency, password security, data ownership, detrimental competition, and hostile insiders are all prospective concerns in cloud security that can be addressed with guidelines.

  . Security and Privacy Threats in Cloud Data Storage Today, the cloud makes software, platforms,

	means that there are significant security and privacy
	problems that must be considered by all parties
	involved in the cloud computing arena while
	employing cloud computing. Cloud computing has a
	number of problems. The following are the issues
	that need to be addressed.
	5.1 Handle Access for Remote Work
	One of the most appealing features of cloud
	applications is that they can be accessed from any
	device with an internet connection. However, more
	apps mean more URLs and passwords to maintain and
	support, and the rise of mobile devices adds yet
	another access point to handle. IT departments must
	facilitate access across multiple devices and platforms
	without compromising security.

infrastructure, and storage more flexible and economical for businesses of all sizes. In this part, we'll discuss the security and privacy risks associated with cloud data storage. Security and privacy are broad topics in cloud computing. In comparison to traditional systems, the cloud has novel security requirements

[START_REF] Sun | Critical Security Issues in Cloud Computing: A Survey[END_REF]

. Because the consumer no longer owns the infrastructure, traditional security architecture is broken. When data is kept on a remote server, users lose physical control over it

[START_REF] Wang | Toward publicly auditable secure cloud data storage services[END_REF]

, and they delegate that control to an untrustworthy cloud provider or party. Because cloud computing is made up of numerous technologies, such as databases, operating systems, different networks, transaction management,

[START_REF] Wei | Security and privacy for storage and computation in cloud computing[END_REF]

virtualization, it poses a number of security risks. As a result, security concerns about these systems and applications apply to the cloud computing as well. Privacy is a complex topic that has different interpretations depending on contexts, cultures and communities, and it has been recognized as a fundamental human right by the United Nations

[START_REF]The Universal Declaration of Human Rights[END_REF]

. Other difficult challenges in cloud computing security include the formulation of a legal definition for cybercrime, the issue of jurisdiction (who is liable for what information and where are they held responsible for it), and the regulation of data transfers to third nations. Access control, user authentication, and data encryption

[START_REF] Bigo | Fighting cybercrime and protecting privacy in the cloud[END_REF]

are all standard security features offered by most cloud storage providers. This

  in the face of the most terrifying tragedies. With cloud services, you can count on quick data recovery in an emergency, be it a natural disaster like a flood or human-made trouble such as a fire or even something as simple as power outages. All of your valuable data is inextricably linked to the office computers if your company does not invest in a cloud-computing solution. This may not appear to be a concern, but if your local hardware fails, you could lose your data forever. Computers can fail for a variety of causes, ranging from viral infections [146] to age-related hardware degeneration to simple user error. They can also be misplaced or stolen, despite the best of intentions. If we don't use the cloud, you risk losing all of the data you've saved locally. With a cloud-based server, however, all of the data you've uploaded to the cloud is safe and accessible from any computer with an internet connection, even if your primary computer isn't working.

	frequently kept once but shared by several users in healthcare [143]. The advantages of cloud everyone must prepare. When such unforeseeable	bank to issue you a code by email or phone. To gain 7.4 Flexibility 7.11 Loss Prevention
	[139]. This reduces storage space and lowers cloud computing are numerous and remarkable. Here are events hit, however, any organisation might suffer	access to your accounts, we are entering this code into
	service provider costs, but attackers who know the just few of the many cloud computing advantages significant losses. While physical infrastructure	the system. Hackers will have a harder time gaining Clients benefit from a great deal of flexibility
	hash code of the stored files can access the data. The discussed. failure can be remedied, the loss of data has a long-	access to your emails, personal information, or provided by the cloud computing. The cloud makes
	sensitive data could then be leaked on the cloud. So, term impact on an organization's structure and	financial information if you take this extra step. service testing and deployment a breeze. Customers
	proof of ownership approach has been proposed to 7.1 Time-Saving, On-Demand Services stability [145]. On the other side, storing data in the	can pick and choose which services they want and
	check the authentication of cloud users. Idziorek et. cloud protects all of your vital information from	6.30 Deploy Multi-Factor Authentication (MFA) how much they want to pay for them. By providing a
	al. proposed this question and researched on the detection and identification of fraud resource consumption [140]. 6.27 Perform Data Backups Ensure that you only engage with cloud service Self-service delivery is a characteristic of cloud computing for various workloads and requirements. Its allure stems from the fact that any service can be accessed on demand. This means you can gain new capabilities right away without investing in new hardware or software. damage, even 7.8 Easily Manageable	The combinations are frequently insufficient to secure conventional username and password user accounts from hackers, and stolen credentials are one of the most common ways for hackers to get access to your online business data and apps. They can log into all of the cloud-based programs and services variety of services, cloud services can better meet changing business demands. If any application provided by the cloud is not getting our job done, we have the flexibility to switch to another cloud. 7.5 Easy Data Backup and Restore
	providers who back up your data. We don't want all 7.2 Sustainability	that you use every day to run your organization once Data backup and restore has become a critical
	of your data to be stored on a single server. If that Cloud computing enables IT maintenance and	they have your user credentials [141]. Multi factor requirement for businesses as the number of cyber-
	server goes offline, you won't be able to access your Given the current situation of the environment, it is management to be simplified and improved through	authentication (MFA) protects all of your cloud users, attacks and security breaches has increased. Cloud
	data. Even if you save your most sensitive data in the no longer sufficient for businesses to place a recycling SLA-backed agreements, central resource	ensuring that only authorized workers can log in to computing solutions can help you store vital data
	cloud, you should consider backing it up on your own bin in the break room and claim that they are helping administration, and managed infrastructure. We get	your cloud apps and access critical data in your on-or offsite, duplicate it, and restore it when needed.
	external hard drives. This will provide you with an the environment. True sustainability necessitates to enjoy a basic user interface without any	off-premise environment. MFA is one of the simplest Traditional data backup and restore alternatives are
	extra layer of protection should something happen solutions that address waste at all levels of a company. requirement for installation and we are assured	yet most effective security measures for preventing available, but they are inefficient and difficult to
	with your cloud provider. Cloud hosting is more environmentally friendly and guaranteed and timely management, maintenance,	hackers from gaining access to your cloud scale. Cloud-based data backup allows you to save a
	leaves a smaller carbon footprint [144]. Cloud and delivery of the IT services.	applications. In fact, most security experts will warn large amount of data in the cloud and expand your
	6.28 Access to Data infrastructures help the environment by powering	you that failing to deploy MFA as part of your storage space without the need for additional
	virtual services rather than actual items and 7.9 Increased Collaboration Enterprise data must only be accessed and viewed by hardware, minimizing paper waste, increasing energy administrators, not by users. This access will improve efficiency, and lowering commuting emissions. Based Cloud computing is primarily designed to enhance	hardware. Most of the cloud backup service providers infrastructure as a service (IAAS) design is now ensure that data is encrypted during upload and regarded careless. download. They also meet data security and
	the security of data stored in the cloud. Although many cloud apps are designed to facilitate client on the expansion of cloud computing and other work operations, which includes data exchange virtual data alternatives, a Pike research report between co-workers and business partners.	compliance requirements. VII. Benefits of Cloud Computing
	collaboration, free programming trials and join opportunities make cloud administrations accessible to unscrupulous clients. DoS attacks, email spam, computerised click extortion, and pilfered content are only a few of the actual assault types that can ride in anticipated that data center energy consumption will Organizations demand more apps for file sharing and decline by 31% from 2010 to 2020. streamlined workflows. Remote workers can instantly connect and communicate with fellow employees and 7.3 Flexible Costs important clients.	7.6 Improved Mobility To put it another way, cloud computing is computing that is fully based on the internet. People no longer Apps and data may be accessed from anywhere at any need to download software from a server or a physical the rising number of mobile devices such as computer to run programs or apps; instead, cloud time thanks to the cloud. All of this is attributable to
	on a download or sign in. The cloud flips the script on traditional capital 7.10 Carbon Footprint	computing services enable them to access those smartphones and tablets. The "anywhere, anytime"
	expenditure investment, with the vast bulk of cloud	applications via the internet [142]. Cloud computing benefit also certainly applies to business. Employees
	6.29 Enable Two Factor Authentication spending being operational. Since a third-party Cloud computing is assisting businesses in reducing	is a type of computing in which software and services gain flexibility, becoming more efficient with
	vendor will take care of maintenance, a company their carbon impact. Organizations only use the When you log onto a website using two-factor resources they require, avoiding any unnecessary	are supplied virtually across a private or public workflows and customer service.
	over-provisioning.	7.7 Disaster Recovery
		Unexpected events, natural disasters, and operational
		hiccups are an unavoidable reality for which

storage, de-duplication technology is extensively employed, which means that the same data is authentication, you must submit two pieces of information. Let's pretend we're logging into your bank's website. We begin by providing your login and password, as is customary. We next wait for your network. The cloud's fundamental goal is to provide cost-effective, adaptable resources to improve user experience. The practice of installing remote servers accessed via the internet to store, manage, and process healthcare-related data is known as cloud computing doesn't have to fund a support team to fix problem servers. The initial expenses of infrastructure requirements, such as the purchase of local servers, are significantly reduced.

Dr. Nikhat Akhtar et al Int J Sci Res Sci Eng Technol, September-October-2021, 8 (5) : 113-152

Dr. Nikhat