RSA-Based Collusion Resistant Quorum Controlled Proxy Re-encryption Scheme for Distributed Secure Communication

Threshold-Proxy Re-Encryption Scheme with Proactive Property for Secure Data Sharing on Cloud

“…Proxies can be malicious and perform wormhole attacks. The existing threshold proxy re-encryption schemes [10], [20], [21], [22] do not satisfy some of the desirable properties of PRE scheme like collusion safety, non-transitive, non-interactive, and unidirectionality. In existing schemes, if any proxy wants to leave or join the quorum then these schemes cannot update the quorum by sharing new shares without changing the secret.…”

“…We analyze and compare the PB-TPRE scheme with existing TPRE schemes [10], [15], [20], [21], [22] based on enumerated properties of PRE scheme, semantic (IND-CPA) security, parallel computation, verifiability of final re-encrypted ciphertext, and proactive nature. PB-TPRE scheme helps transform the outsourced encrypted data of the data owner into a re-encrypted ciphertext for the user after performing t partial re-encryption concurrently afterward combines them without regulating the proxies in any sequence.…”

“…The re-encryption key in the PB-TPRE scheme is generated using a public key of the user, and a private key of the data owner and decryption requires the private key of the user and hash of requested data keyword due to the uses of the minimal number of keys in re-encryption key and decryption, make our PB-TPRE scheme key optimal. However, the [20] scheme uses the RSA algorithm to generate the public and private keys. The RSA algorithm requires a large number of bits to provide security than the elliptic curve, and [22] scheme uses the public key of the user and the private key of the data owner, which is generated from the elliptic curve.…”

“…collusion of proxy with malicious users. Existing schemes [10], [15], [20], [21], [22] require the central dealer for re-encryption. While, [22] scheme claims that they do not require the central dealer, but they fixed the proxy first and last proxy to receive the final re-encrypted ciphertext and transfer to the user that fixed last proxy behaves like a central dealer.…”

“…However, the [10] scheme is transitive because after the collision attack secret of the data owner transferred to anyone to decrypt all his outsourced data. The [20], [21] schemes are transferable because, in the [21] scheme if user added private key of other user C sk c and subtract his private key sk u from re-encryption key that transfer user re-encryption (R do→u ) into the re-encryption key of user C (R u→c ). In the [20] scheme, if user multiply his private key and public of other user C in re-encryption (R do→u ) then the re-encryption generated for user (R do→u ) will transfer into re-encryption of user C (R u→c ) that makes both [20], [21] scheme insecure.…”