1- PKG gives data owner user public key (user ID) for every user in the system.
2- The Data Owner stores encrypted files on the cloud server with attributes.
3- When a user requests access, he would obtain the file`s secret key from the Data Owner.
4- Cloud Server gives every user in the system the encrypted files with attributes assigned to each user. A system administrator is a cloud administrator (cloud A) that maintains the cloud system, and is responsible for the integrity of the data, as well as, the efficiency and performance of the system. …show more content…
RSA is best known and widely used for public-key generation. The algorithm is based on exponentiation in a finite (Galois) field over integers of modulus of a prime. RSA use large integers (eg. 1024 bits) and the cost of their security depend on the factorization of large numbers. RSA is an algorithm for public key cryptography. It involves the use of two keys: o A public key, which can be common, and used to encrypt messages. o A private key, known only by the recipient, and used to decrypt messages.
The RSA algorithm (Key generation)
Choose 2 distinct random prime numbers: p, q
Compute n = p.q
Compute ø (n) = (p-1)