ID-based threshold decryption without random oracles and its application in key escrow

Abstract

In this paper, we first present an ID-based threshold decryption scheme ThD based on bilinear Diffie-Hellman inversion assumption, and prove that it is selective chosen plaintext secure without random oracles. Then, we enhance ThD to a more secure level with ciphertext validation test before decryption. At last, we apply ThD to key escrow, resulting in a robust threshold key escrow system.