摘要： 基于双线性对的门限密码体制过度依赖双线性对结构，而双线性对计算复杂度较高，严重影响秘密共享方案的效率。为此，提出利用Shamir门限共享方案实现双线性对群元素门限分享的新方案，借助整数秘密共享方案间接地实现基于身份私钥的分配。分析结果表明，该方案仅需2次双线性对计算，为设计高效的基于身份的门限密码体制奠定了基础。

关键词: 基于身份的密码体制, 门限密码体制, 秘密共享, 双线性对, 基于身份私钥, 公钥基础设施

Abstract: Threshold cryptographic scheme based on bilinear pairings depends too much on the bilinear pairing tool, but the computation of the bilinear pairing is very time-consuming so that the efficiency of secret sharing scheme is affected badly. By using Shamir threshold sharing scheme, this paper proposes a new method which threshold shares in the bilinear group. Its based-identity private key can be shared through the secret sharing scheme for integers. Analysis result shows that the new method needs only two times bilinear pairing computations and can be used to further design efficient identity based threshold cryptographic schemes.

Key words: identity-based cryptography, threshold cryptography, secret sharing, bilinear pairing, identity-based private key, Public Key Infrastructure(PKI)

中图分类号: 

• TP309.2