# Secure Cloud Infrastructure: A Survey on Issues, Current Solutions, and Open Challenges
## 5 Related Existing Solutions in Cloud Levels
### Solutions at Data Level
The proposed method achieves the availability, reliability, and integrity of data travelling through the server owner to the cloud and from the cloud to the customer. In addition, it also offers more flexibility and allows the user to retrieve files from the cloud by searching for encrypted data. The study in [56] identified problems related to cloud data storage, such as data breaches, data theft, and cloud data unavailability. The study proposed potential solutions to those issues. The proposed solutions addressed issues related to identity management and access control. However, there are many issues related to access control and identity management that are still unsolved, such as weak credentials that can easily be reset, denial of service attack to lock the account for a period of time, weak logging and monitoring capabilities, and XML wrapping attacks on web pages. The authors in [57] proposed a new technique called match-then-decryption, in which a matching phase is added before the decryption phase. This technique works by computing special components in ciphertexts used to verify whether the private key attribute matches the hidden access policy in ciphertexts without decryption. Formal security analyses and comparisons showed that the suggested solutions simultaneously ensure privacy attributes and increase the efficiency of decryption for outsourced cloud data storage. In [58], the authors proposed a system to enhance the RSA algorithm by increasing the key size to strengthen the encryption process. The proposed algorithm reduces the time required for encryption and decryption by dividing the file into blocks and enhances the strength of the algorithm by increasing the key size. This power paves the way for users to store data in the cloud efficiently. The study in [59] used elliptic curve cryptography (ECC) to encrypt data in the cloud environment because the key size used by ECC is very small. Owing to the small key size of the ECC, the computing power is reduced, and the energy consumption is minimized. This study showed that ECC is fast and more effective for data protection in a cloud computing environment and reduces computing power and also improves performance. The authors in [60] suggested a hybrid algorithm to improve cloud data security using an encryption algorithm. To improve cloud security, this study combined homographic and blowfish encryption algorithms. The blowfish algorithm was used to generate a security key. A symmetric key block was used for both decryption and encryption. Homographic encryption, on the other hand, provides confidentiality of data and prevents storing the information in plain text at any stage. In [61], the authors proposed a novel lightweight encryption algorithm consisting of combining a symmetric algorithm for encrypting data and an asymmetric one for distributing keys. This combination allows users to benefit from successful asymmetric encryption protection and rapid symmetric encryption performance while maintaining uses' rights to protected and permitted access to data. The findings reveal that the lightweight algorithm's processing time is faster than state-of-the-art cryptographic algorithms. In the study [8], the authors suggested a hybrid layered approach to protect the data of the user, along with a combination of a lattice-based security technique. A new approach was introduced for responsibilities and roles examination using the lattice model. The AES and RSA algorithms were used to provide sensitive data with more and better protection. The study in [60] proposed a hybrid algorithm to enhance the security of cloud data using an encryption algorithm. It combined homographic encryption and blowfish encryption to enhance cloud security. However, this hybrid algorithm does not appear to be effective in practice, as the homographic encryption is extremely slow and computationally expensive, to the point that it is not currently practical.