Fully secure unidirectional identity-based proxy re-encryption

Abstract

Proxy re-encryption (PRE) allows the proxy to translate a ciphertext encrypted under Alice's public key into another ciphertext that can be decrypted by Bob's secret key. Identity-based proxy re-encryption (IB-PRE) is the development of identity-based encryption and proxy re-encryption, where ciphertexts are transformed from one identity to another. In this paper, we propose two novel unidirectional identity-based proxy re-encryption schemes, which are both non-interactive and proved secure in the standard model. The first scheme is a single-hop IB-PRE scheme and has master secret security, allows the encryptor to decide whether the ciphertext can be re-encrypted. The second scheme is a multi-hop IB-PRE scheme which allows the ciphertext re-encrypted multiple times but without the size of ciphertext growing linearly as previous multi-hop IB-PRE schemes. © 2012 Springer-Verlag.