An Efficient Certificateless Threshold Decryption Schemes Based On Pairings

Abstract

As the combination of certificateless encryption and threshold cryptography, the certificateless threshold decryption (CLTD) scheme can avoid both the single point of failure in the distributed networks and the inherent key escrow problem in identity-based cryptosystem. This paper presents a CLTD schemes from pairings. We use the Shamir secret sharing method to indirectly split the private keys in the group G into the shares in the finite field Zq. Our CLTD scheme succeed in involving much less pairing computation for generating or verifying decryption shares. The decryption share supports short length, fast generation and batch verification. Sharing the private key is completed by its holder himself without needing help from KGC. The security proof is provided in the random oracle model.