A Novel Proxy Re-Encryption with Keyword Search

In this paper, a novel proxy re-encryption (PRE) scheme with keyword search is proposed, where only the ciphertext containing the keyword set by the delegator can be transformed by the semi-trusted proxy and then decrypted by delegatee. In the proposed scheme, the semi-trusted proxy can convert the ciphertext encrypted under the delegator’s public key into the ciphertext encrypted under the delegatee’s public key. In addition, only the delegatee’s email gateway with a trapdoor can test whether or not a given cipheretext containing some keyword, but can learn nothing else about the sensitive data of email. We proposed an identity-based proxy re-encryption with keyword search scheme, where the delegator and the delegatee extract keys from a trusted party called the key generator center (KGC), who generates public-private key pair for delegator and delegatee based on their identities. Meanwhile, the identity-based proxy re-encryption with keyword search scheme satisfies the properties of PRE including unidirectionality, multi-use and transparency. Additionally, the proposed scheme is efficient in terms of both computation and communication, and can realize security privacy preserving in cloud computing environments.