To tackle with the security lack in the password-authenticated key exchange protocol, this paper proposes a two-party password-authenticated key exchange protocol based on a verifier. In the proposed protocol, a user ...To tackle with the security lack in the password-authenticated key exchange protocol, this paper proposes a two-party password-authenticated key exchange protocol based on a verifier. In the proposed protocol, a user stores his password in plaintext, and the server stores a verifier for the user’s password, using DL difficult problem and DH difficult problem, through the session between user and server to establish a session key. The security discussion result shows that the proposed protocol provides forward secrecy, and can effectively defend against server compromising fake attacks, dictionary attacks and middleman attacks. Protocol efficiency comparisons reveal our protocol is more reasonable.展开更多
As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and mos...As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ＇ s scheme, Gorantla, et al. ＇ s scheme and Ming, et al. ＇ s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.展开更多
工业物联网(industrial Internet of things,IIoT)设备通过云端收集和存储数据时,会遇到数据认证和隐私保护等问题.属性基签名(attribute-based signature,ABS)不仅可以实现数据认证,而且可以保护签名者的身份隐私.目前存在的SA-ABS(ser...工业物联网(industrial Internet of things,IIoT)设备通过云端收集和存储数据时,会遇到数据认证和隐私保护等问题.属性基签名(attribute-based signature,ABS)不仅可以实现数据认证,而且可以保护签名者的身份隐私.目前存在的SA-ABS(server-aided ABS)方案中,借助服务器减小了签名者和验证者的计算开销,而且通过抵抗签名者和服务器的共谋攻击保证了服务器辅助验证阶段的安全性.但是,现有的SA-ABS方案都不能对服务器产生的部分签名进行有效性验证,所以存在服务器对部分签名伪造的安全隐患.为克服这一挑战,提出一种服务器辅助且可验证的属性基签名(server-aided and verifiable ABS,SA-VABS)方案,该方案不仅减小了签名者和验证者的计算开销,而且通过抵抗签名者和服务器的共谋攻击来保证服务器辅助验证阶段的安全性,最重要的是对服务器产生的部分签名进行了有效性验证,从而保证了服务器辅助签名产生阶段的安全性.形式化安全性分析表明SA-VABS方案是安全的.仿真实验和对比分析表明SA-VABS方案在保证效率的同时提高了安全性.展开更多
文摘To tackle with the security lack in the password-authenticated key exchange protocol, this paper proposes a two-party password-authenticated key exchange protocol based on a verifier. In the proposed protocol, a user stores his password in plaintext, and the server stores a verifier for the user’s password, using DL difficult problem and DH difficult problem, through the session between user and server to establish a session key. The security discussion result shows that the proposed protocol provides forward secrecy, and can effectively defend against server compromising fake attacks, dictionary attacks and middleman attacks. Protocol efficiency comparisons reveal our protocol is more reasonable.
基金Supported by the National High Technology Research and Development Programme of China （ No. 2008AA092301 ） and the National Natural Science Foundation of China （No. 50879014）.
文摘As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ＇ s scheme, Gorantla, et al. ＇ s scheme and Ming, et al. ＇ s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.
文摘工业物联网(industrial Internet of things,IIoT)设备通过云端收集和存储数据时,会遇到数据认证和隐私保护等问题.属性基签名(attribute-based signature,ABS)不仅可以实现数据认证,而且可以保护签名者的身份隐私.目前存在的SA-ABS(server-aided ABS)方案中,借助服务器减小了签名者和验证者的计算开销,而且通过抵抗签名者和服务器的共谋攻击保证了服务器辅助验证阶段的安全性.但是,现有的SA-ABS方案都不能对服务器产生的部分签名进行有效性验证,所以存在服务器对部分签名伪造的安全隐患.为克服这一挑战,提出一种服务器辅助且可验证的属性基签名(server-aided and verifiable ABS,SA-VABS)方案,该方案不仅减小了签名者和验证者的计算开销,而且通过抵抗签名者和服务器的共谋攻击来保证服务器辅助验证阶段的安全性,最重要的是对服务器产生的部分签名进行了有效性验证,从而保证了服务器辅助签名产生阶段的安全性.形式化安全性分析表明SA-VABS方案是安全的.仿真实验和对比分析表明SA-VABS方案在保证效率的同时提高了安全性.
