A. RSARSA stands for Ron Rivest, Adi Shamir and Leonard Adleman. It is a public key cryptographic system used for secure data transmission. Two different keys are used in this. One is the public key used for encryption and the other is the private key used for decryption. In [1], they mainly focused on data security issues in the cloud such as: 1) Privacy and confidentiality, which means that once the user has hosted the data in the cloud, there should be some guarantee that access such hosted data will only be limited to authorized access. It is guaranteed by authentication services, security protocols and data encryption services. 2) Data integrity, which means that the data sent is the same as the message received, i.e. it is not altered in the meantime. It is secured by firewalls and intrusion detection system (IDS). 3) Data availability, which means that data should be available to users when they need it. 4) Data localization and relocation, which means that data can be moved from one location to another because cloud providers have contracts with each other, so they can use each other's resources. In the cloud computing environment, plain text is converted into ciphertext by the cloud service provider and returned to the original data by the cloud user. Only the authorized user can access the data. If an unauthorized person obtains the data intentionally or by mistake, he or she will not be able to obtain the original data. In [2], they addressed the secure hybrid framework to ensure data security in cloud computing, which includes RSA public key algorithm, private key algorithm AES and SHA algorithm used to convert arbitrary sized messages into hash code with the help of the hash function. They have a built-in fingerprint mechanism to enhance authentication… the core of the card… is generated using a secure hash algorithm which is combined with the digital signature to form a concatenated string. This concatenated string is then encrypted with the help of the recipient's public key and sent to the cloud user who requested the data. Then the decrypted message is converted into the message digest by SHA for data integrity verification and RSA is used to validate the fingerprint.1) Advantages: Produces a fixed length output by applying a hash function on the actual data. So, it is easy to calculate the fixed length output. It is a collision-resistant algorithm and provides a one-way hash. Its attack protection is also stronger than other algorithms.2) Disadvantages: It is a slower computational algorithm than the MD5 algorithm. Has known security vulnerabilities. Choosing an effective hash function for a specific application is a difficult task.