## 3 Security Issues And Challenges
### Security Issues  
CC has several security issues, such as misuse and excessive utilization of resources, malicious insiders, insecure and unreliable APIs, data corruption or leak, account takeover, and shared technology vulnerabilities [30; 31]. Other serious risks to the security of CC are DoS and DDoS attacks [9; 31], as indicated by an ongoing CSA research [32]. A properly secured CC ensures the security of the website it hosts and vice versa [33]. The demand for CC security is becoming increasingly noticeable and outstanding. Even though the security of CC is at its nascent stage and still developing, an assortment of CC clients is already demanding various security requirements, which can vary for each CSP; even the same client could have different security requirements. The CC clients can be individuals, academic institutions or corporations, and software developers; every one of them might have specific security prerequisites. According to several researchers [34; 35], the following are the security issues related to CCC and CSP:  
* _Data-related issues:_ The CSPs must guarantee the security and availability of the data transferred by the CCCs and prevent any conceivable security breaches. The owners of CSPs should utilize solid security approaches to ensure data availability and security. For example, there are various authorization approaches to control data, such as isolating clients' data in the CC storage unit so that nobody other than the authorized client can access the data or modify its availability. * _Data integrity:_ In an independent system, data integrity can be guaranteed by taking into consideration atomicity, consistency, isolation, and durability (ACID) properties. It should be possible through decentralizing approach by utilizing a central manager. However, data integrity on CC is a big challenge. The greatest challenge with web services at the application layer is transaction management since the HTTP protocol cannot provide an ensured and available service. So, the best choice is to leave this on the level of API. In any case, available standards, such as transaction of web services and reliability of web services, are not yet developed. The absence of control at the data level could bring about significant integrity issues. * _Availability:_ It is crucial to maintain the availability of CC applications for better user accessibility. Therefore, CSPs must guarantee non-stop service to their CCC, including expansibility to support the business continuity of their users. * _Privileged user access:_ It is common for CCC to keep sensitive data in the CC; therefore, users require various levels of privileges to access that information. There must be a control system for accessing information for different users. * _Data recovery and backup:_ By providing backup services, CSPs should guarantee clients' data recoverability caused by disasters or accidental damage. The backup data should be replicated on multiple distributed servers while maintaining integrity and privacy, allowing data to be restored whenever needed. * _Investigative support:_ Investigating incidents in the CC environment is difficult if the logging data constantly moves over multi-sites. CCC must obtain contractual obligations from the CSP to investigate every inappropriate or criminal event. * _Long-term viability:_ CCC should obtain a guarantee that their data is consistently accessible to them, even after an alteration or changes in the CSP policies and terms. * _Network security:_ CSPs are required to ensure data security during transit or network transfers to prevent critical or sensitive information leakage. * _Web application security:_ Services on CC must be overseen over the website utilizing the internet browser. Every security imperfection in the service application influences all the CCCs using the same service application. Even though they do not successfully process the security issue, numerous conventional security approaches exist.