Comparative Study of Public-key cryptosystems in Cloud Storage

Cloud storage is a service model in which data is maintained, managed and backed up remotely and made available to users over a network (typically the Internet). Cloud storage can provide the benefits of greater accessibility and reliability. In cloud storage different members can share that data through different virtual machines but present on single physical machine. But the thing is user don’t have physical control over the outsourced data. As a result there is a need of effective method to share data securely among different users. This can be achieved using cryptography, which helps in encrypting the data to be stored in cloud storage to protect against unauthorized access. Here we introduce a public-key cryptosystem which produce ciphertexts of constant size such a way that an systematic assignment of decryption virtue for any number of ciphertexts are possible. The modernity is that one can combine a set of secret keys and make them as mini single key with holding the same ability of all the keys that are formed in each group. This compact aggregate key can be efficiently sent to others or to be stored in a smart card with little secure storage. DOI: 10.17762/ijritcc2321-8169.150314