关键词: 密钥托管, 密钥撤销, 仲裁者, 基于仲裁的身份加密, 仲裁实体

Abstract: Combining mediated encryption with Certificateless Public Key Encryption（CL-PKE）, a new Variant Mediated Identity-Based Encryption (V-MIBE) scheme based on computational bilinear Diffie-Hellman assumption was presented. New scheme not only solved the problem of key escrow by the idea of CL-PKE but also provided fast key revocation with mediator. New scheme can resist the attack of replacing user's public key. Compared with the existing identity-based encryption scheme, the security of new scheme improves remarkably.

Key words: key escrow, key revocation, mediator, Variant Mediated Identity-Based Encryption (V-MIBE), Security Mediator (SEM)