## 5 Final Remarks
### Discussion  
Cloud computing comprises heterogeneous resources at different geographical locations requiring a secure-aware approach to handling security threats. Private sensitive data belonging to distinctive organisations in community clouds should be separated to avoid intervening. This has become primarily impossible due to virtual machine image sharing among cloud providers [53]. Most present proactive mechanisms from the literature do not consider systems run time adaptation to either the authorisation infrastructure or service. That is, simultaneous detection or prevention in responding to abnormal behaviours: exceeded login attempts by malicious intruders when accessing a piece of information can be automatically tagged malicious without requiring any cryptographic scheme and human intervention. Furthermore, data-centric security information confidentiality should be preferred because it allows perfect forward secrecy, which is critical in mitigating against attackers eavesdropping or intercepting information in transit or at rest. Additionally, it minimises information security compromise and decreases the effect of the overall attack. Nevertheless, this approach will require techniques and protocols for originating temporary keys and the issue of regular updates. Without perfect forward secrecy, the confidentiality of data will depend on the efficiency of encryption keys, meaning that if private keys are leaked, packets might be decrypted when intercepted by an attacker. The inaccuracy in most developed systems results from the total dependency on cryptographic schemes. Because, in any case, where a loophole is found in the cryptographic scheme, then the entire system becomes invalid. Therefore, the evaluation of such cryptographic methods can be termed dangerous [97]. Authentication for cloud storage should not only depend on encryption schemes. Providing effective encryption schemes demands algorithms with significant key strengths. The limitations of large key strengths for cloud authentication are speed, processing power, and computational resources in encrypting a large amount of data. As key sizes increase, the maintenance and management of large key sizes become a bottleneck for the server. Cloud auditability also poses a significant issue, such as ascertaining the integrity of the data stored in the cloud without downloading the data first before uploading the data. Cloud privacy protection and data security are primary issues for IaaS, Paas, and SaaS delivery models [76]. The security challenge is protecting privacy and PII while sharing data across different enterprises. Standard definitions of cloud policies, user confidentiality and integrity have not been adequately defined and therefore may conflict with each other, affecting the enforcement of confidentiality. Such conflicts have been depicted in previous implementations from literature, such as the complete anonymity to hide users' identities, which will make confidentiality and authentication more challenging. An extreme example is the situation of a shared file accessed by multiple users who may hide their identities due to anonymity for privacy protection, such as in the case of [82]. However, implementing such architectures, malicious users are hard to be tracked because of the user anonymity. Therefore, researchers must seek a trade-off in which the requirement of one attribute can be met while simultaneously maintaining a threshold degree of the other attribute. The need to provide efficient security and privacy in the cloud is paramount [99]. Service providers need to control and guarantee users how their information is being accessed and what kind of information is released to the public. Secure-adaptive techniques should be implemented to enforce strict security in a cloud environment by providing separation between sensitive and non-sensitive data, followed by security mechanism such as encryption, privacy protection, and identity management frameworks.