New Construction of Identity-based Proxy Re-encryption
A proxy re-encryption (PRE) scheme involves three parties: Alice, Bob, and a proxy. PRE allows the proxy to translate a ciphertext encrypted under Alice's public key into one that can be decrypted by Bob's secret key. We present a general method to construct an identity-based proxy re-encryption scheme from an existing identity-based encryption scheme. The transformed scheme satisfies the properties of PRE, such as unidirectionality, non-interactivity and multi-use. Moreover, the proposed scheme has master key security, allows the encryptor to decide whether the ciphertext can be re-encrypted.