制造网格环境下基于身份的指定多接收者签密方案

基于椭圆曲线离散对数困难性假设和Gap Diffie—Hellman问题,提出了一个适用于制造网格环境下的基于身份的指定多接收者签密方案。新方案不仅能够在一个逻辑步骤内实现加密和认证,提高系统效率,而且能够实现一次签密,指定多个特定的接收者解签密并验证,为处在不同信任域的制造网格节点之间的交互认证提供了一种方法。最后基于这个特点,构造了一种适合于制造网格的高效的多信任域交互认证模型。     

Zero-pole cancellation for identity-based aggregators: a constant-size designated verifier-set signature

In this paper we present a designated verifier-set signature (DVSS), in which the signer allows to designate many verifiers rather than one verifier, and each designated verifier can verify the validity of signature by himself. Our research starts from identity-based aggregator (IBA) that compresses a designated set of verifier’s identities to a constantsize random string in cryptographic space. The IBA is constructed by mapping the hash of verifier’s identity into zero or pole of a target curve, and extracting one curve’s point as the result of aggregation according to a specific secret. Considering the different types of target curves, these two IBAs are called as zeros-based aggregator and poles-based aggregator, respectively. Based on them, we propose a practical DVSS scheme constructed from the zero-pole cancellation method which can eliminate the same elements between zeros-based aggregator and poles-based aggregator. Due to this design, our DVSS scheme has some distinct advantages: (1) the signature supporting arbitrary dynamic verifiers extracted from a large number of users; and (2) the signature with short and constant length. We rigorously prove that our DVSS scheme satisfies the security properties: correctness, consistency, unforgeability and exclusivity.     

婴儿配方乳粉中维生素B1、B2含量测定能力验证

目的设计组织婴儿配方乳粉中维生素B_1、维生素B_2含量测定能力验证项目,评价实验室检测婴儿配方乳粉中维生素B_1、维生素B_2的技术能力和水平。方法考核样品中的维生素B_1、维生素B_2在P0.05显著水平时是否均匀,且在整个计划周期内稳定,满足能力验证的要求。通过实施能力验证计划,对来自27个省(自治区)、直辖市的33家实验室的测定结果与指定值比对得到相对偏差,评价实验室检测能力。结果在参加实验室中,维生素B_1总体满意率为90.6%;维生素B_2总体满意率为84.8%。结论多数参加实验室检测能力结果满意,表明乳粉中维生素B_1、维生素B_2检测水平总体良好。对于离群结果进行技术分析,可以帮助实验室查找原因并进行整改。     

层次撤销群签名:概念与构建

群签名是具有中心地位的密码系统,其中一个重要的问题是成员撤销.支持更多方式撤销的群签名方案能使群签名应用于更多的场合和领域;提出一种可层次撤销的群签名方案的概念,即不仅支持普通的VLR撤销某个群成员,还支持撤销某个小组、大组等等的层次撤销;与普通的VLR撤销相比在撤销一组多人时效率从O(R)(R为撤销人数)提高到了O(1);并基于RSA假设和多项式构建出了一个具体的层次撤销群签名方案,构建方法具有独立的意义可用于其他密码系统的构建.     

A strong designated verifier signature scheme tightly related to the LRSW assumption

In this paper, we propose the first strong designated verifier signature scheme with a tight security reduction to the LRSW assumption in the standard model.     

浅论会计委派制对黄金行业发展的影响

论述了会计委派制存在的几种形式，指出会计委派制存在的问题并提出作者的观点，论述了会计委派制对中国黄金行业发展的影响。     

New certificateless aggregate signature scheme with universal designated verifier

Certificateless aggregate signature(CLAS) schemes with universal designated verifier had been widely applied in resource-constrained wireless mobile networks,because they could not only solve the problems of the certificate management and private key escrow,but also realize batch validation and the signer’s privacy protection.A security analysis for a certificateless aggregate signature scheme with universal designated verifier was firstly provided,and two attack methods to demonstrate that their scheme was forgeable was presented.To enhance security,a new certificateless aggregate signature scheme with universal designated verifier was proposed,and then the security of the scheme in the random oracle model was proved.The performance of our proposed scheme was finally evaluated.Compared with the original scheme,the pvoposed scheme fixes the security flaws and the total computational cost is greatly reduced.     

铝加工企业轧制区电气设备维护保养措施

对长期从事设备维护保养的工作经验的总结,指出了部分企业在电气设备维护方面存在一些缺陷和不足,并对设备事故的形成进行了分析,提出了轧制区电气设备维护保养的改进措施。     

浅谈实验室的比对与验证试验

介绍了比对和验证试验类型,举例说明了仪器比对和人员比对试验,并对测试结果进行了数理统计分析,提出了比对与验证试验应注意的问题。有计划地开展比对和验证试验,对提高实验室的检测水平,确保出具检验报告的质量具有重要意义。     

Universal forgery on Sekhar's signature scheme with message recovery

Owing to the abundance of electronic applications of digital signatures, many additional properties are needed. Recently, Sekhar [Sekhar, M. R. (2004). Signature scheme with message recovery and its application. Int. J. Comput. Math., 81(3), 285–289.] proposed three signature schemes with message recovery designed to protect the identity of the signer. In this setting, only a specific verifier can check the validity of a signature, and he can transmit this conviction to a third party. In this note, we show that this protocol is totally insecure, as it is universally forgeable under a no-message attack. In other words, we show that anyone can forge a valid signature of a user on an arbitrary message. The forged signatures are unconditionally indistinguishable (in an information theoretical sense) from properly formed signatures.