摘要： 针对P2P网络中存在密钥泄露和大量数据加密传输困难的问题，采用密钥隔离机制和消息分组链接加密的方法，提出一种具有消息链接性的基于身份密钥隔离加密方案。在随机预言机模型下给出形式化证明，该方案在双线性Deffie-Hellman假设成立的条件下，满足适应性选择消息攻击不可区分性，且该方案具有非限定时间周期以及随机存取密钥更新的性质。性能分析结果表明，该方案的密文长度仅为基本密钥隔离加密方案的一半，适用于P2P网络中传输大量的加密数据。

关键词: 基于身份, 密钥隔离加密, 消息链接, 适应性选择消息攻击不可区分性, 双线性对, 双线性Deffie-Hellman假设

Abstract: Aiming at dealing with the security problem of key exposure and the problem of transmitting big encrypted data in peer-to-peer network, this paper proposes the first novel Identity-based Key-insulated Encryption(IB-KIE) scheme with message linkages by using a key-insulated cryptographic mechanism and plaintext block chain encryption method. In the proposed scheme, each client can periodically update his private key while the corresponding public one remains unchanged. Under the random oracle model, it formally proves that the IB-KIE with message linkages achieves the security requirement of Indistinguishability Against Adaptive Chosen-Ciphertext Attacks(IND-CCA2). The essential security assumption of the proposed scheme is based on the well-known Bilinear Difie-Hellman Problem(BDHP). The proposed scheme has the properties of unbounded time periods and random-access key-updates. By comparing the IB-KIE with message linkages and the basic scheme, the length of the ciphertext in the prior scheme is only half of that in the later. So the IB-KIE with message linkages is suitable for transmitting big encrypted data in Peer-to-Peer(P2P) network.

Key words: Identity(ID)-based, Key-insulated Encryption(KIE), message linkage, Indistinguishability Against Adaptive Chosen- Ciphertext Attacks(IND-CCA2), bilinear pairing, Bilinear Diffie-Hellman(BDH) assumption

中图分类号: 

• TP918.1