Multi-use Deterministic Public Key Proxy Re-Encryption from Lattices in the Auxiliary-Input Setting

Abstract

Proxy Re-Encryption (PRE) is a cryptographic primitive that allows a proxy to turn an Alice’s ciphertext into a Bob’s ciphertext on the same plaintext. All of the PRE schemes are public key encryption and semantic security. Deterministic Public Key Encryption (D-PKE) provides an alternative to randomized public key encryption in various scenarios where the latter exhibits inherent drawbacks. In this paper, we construct the first multi-use unidirectional D-PRE scheme from Lattices in the auxiliary-input setting. We also prove that it is PRIV1-INDr secure in the standard model based on the LWR. Finally, an identity-based D-PRE is obtained from the basic construction.

A Lattice-Based Homomorphic Proxy Re-Encryption Scheme with Strong Anti-Collusion for Cloud Computing

“…In this section, we will use the above homomorphic encryption (HE) scheme to construct the HPRE-SAC scheme by using Trapdoor Sampling [ 27 , 48 ].…”

“…In addition, although our HPRE-SAC scheme is single bit encryption, we can use homomorphic ciphertext packing technology [ 51 ] and trapdoor based multi bit proxy re-encryption scheme [ 27 ] to construct a multi bit homomorphic proxy re-encryption scheme against strong collusion attack.…”

“…Many PRE schemes with special properties have been constructed to meet the increasingly complex cloud sharing environment. For example, conditional proxy re-encryption [ 18 , 19 ], which allows only the ciphertexts satisfying a condition to be converted by the proxy; attribute-based proxy re-encryption [ 20 , 21 ], which transforms a ciphertext under an access policy to a ciphertext under another access policy; broadcast proxy re-encryption [ 22 , 23 ], which converts a ciphertext to a set of ciphertexts under different users at a time; unidirectional proxy re-encryption [ 24 , 25 ], in which the proxy can use the re-encryption key to convert the delegator’s ciphertext to the delegatee’s ciphertext, but cannot reverse the conversion, otherwise it becomes bidirectional; multi-hop proxy re-encryption [ 26 , 27 ], in which the proxy can convert a re-encryption ciphertext into a re-encryption ciphertext of other users, otherwise it becomes single-hop; homomorphic proxy re-encryption (HPRE) scheme [ 19 , 28 ], and so on.…”