关键词: 认证密钥协商, 移动漫游服务, 基于身份密码体制, 计算Diffie-Hellman问题, 扩展的CK模型

Abstract: As mobile devices usually have limited computing and storage resources,it is difficult to develop an anonymous two-party authentication scheme possessing performance efficiency and strong security simultaneously.The existing two-party authenticated key agreement schemes for roaming service do not resist the attack of ephemeral secrets reveal,and have high computation costs.Therefore,a new anonymous two-party authenticated key agreement scheme for roaming service was proposed in this paper,in which an efficiency identity-based signcryption scheme was adopted to achieve mutual authentication and unlinkability.The identity-based signcryption scheme is based on the Schnorr signature scheme,a very efficient elliptic curve digital signature algorithm,which greatly reduce the total computation cost during one authentication session in comparison with existing authentication schemes.Furthermore,to achieve the security of the ephemeral secrets reveal resistance in the new authentication scheme,we constructed a computational Diffie-Hellman problem instance that required two participants to compute a value by combining its own private key with its peer's public key,respectively.We extended the eCK model to model the two-party authenticated key agreement schemes for roaming service,discussed the distinction between the security game of authenticated key agreement schemes for mobile roaming service and the general one,and demonstrated that the new scheme was provably secure in the extended eCK model.The conclusion indicates that the security of the new scheme can be reduced to solve the computational Diffie-Hellman problem on an elliptic curve over finite field by a polynomial-time adversary.Comparative analysis shows that our scheme has stronger security,needs less cryptography library,and has lower computing and communication overheads.The new scheme can be used to provide secure roaming authentication for resource constrained mobile terminals in global mobility networks,Internet of things or ubiquitous networks.

Key words: authenticated key agreement, mobile roaming service, identity-based cryptography, computational Diffie-Hellman problem, eCK (extended Canetti-Krawczyk) model