Proxy Re-encryption Scheme based on New Multivariate Quadratic Assumptions

In PKC 2012, a public key encryption based on new multivariate quadratic assumptions is proposed. The compactness and security of the algorithm illumined us in applying it in proxy re-encryption scheme. In this paper, a novel unidirectional PRE scheme (NMQ-PRE) is constructed based on new multivariate quadratic assumptions. The new scheme is a formal PRE scheme and compact in cryptographic protocols. By applying the nature property of multivariate quadratic assumptions, NMQ-PRE is proved chosen ciphertext attack in standard model. Compared with the traditional PRE scheme based on RSA or pairings, NMQ-PRE is computationally efficient and simpler. Finally, a NMQ-PRE scheme for message block is built for application convenience, such as file sharing or mail forwarding.