Efficient identity-based GQ multisignatures

ISO/IEC 14888 specifies a variety of digital signature mechanisms to sign messages of arbitrary length. These schemes can be applied to provide entity authentication, data origin authentication, non-repudiation, and data integrity verification. ISO/IEC 14888 consists of three parts under the general title Information technology—Security techniques—Digital signatures. Part II, or ISO/IEC 14888-2 specifies the general structure and the fundamental procedures for the generation and verification of an identity-based signature (IBS) mechanism for messages of arbitrary length. Particularly, the IBS scheme of Guillou and Quisquater (GQ) is described in Clauses 6–8. In this paper, an efficient identity-based multisignature (IBMS) scheme is proposed for the GQ IBS scheme, which allows multiple users using the ISO/IEC 14888-2 standard GQ scheme to generate multisignatures. The scheme is efficient in the sense that both the length and the verification time of the multisignatures are fixed. The proposed ID-based multisignature scheme is also secure against forgeability under adaptive chosen-message attack and adaptive chosen-identity attack in random oracle model.     

责任性子群多重签名的定义与实现

定义了一种多重签名机制 :责任性子群多重签名 (Accountable -SubgroupMultisignatures ,ASM )。ASM机制能够使已知的签名者G的任一子群S有效地签发消息M ,且签名可以向任一验证者证明S中每个签名者的身份。其中 ,第一个多重签名的安全形式化模型要包括密钥的产生 (在无可信任第三方的情况下 ) ;基于Schnorr数字签名的协议必须是可验证的和有效的 :每次签名只需三方通信 ;无论有多少个签名者 ,每个签名者的签名时间与单个Schnorr签名方案的时间相同 ;验证时间与单个Schnorr签名方案的验证时间相差无几 ;无论有多少个签名者 ,签名的长度与单个Schnorr签名方案的签名长度相同。ASM的安全的证明是基于Randomoracles和离散对数问题难度的     

基于椭圆曲线的多重盲签名方案

提出了两个基于椭圆曲线的多重盲签名方案,该方案可以同时完成盲签名和多重签名的任务而且签名尺寸不会随签名人数增加而增加。还对方案的正确性、盲性、不可伪造性作了证明。     

Non-interactive multisignatures in the plain public-key model with efficient verification

Multisignatures extend standard digital signatures to allow an ad hoc set of users to jointly sign a message. Multisignature schemes are often evaluated from the following perspectives: (1) the cryptographic assumptions underlying the schemes; (2) the operational assumptions about the bootstrapping of the schemes in practice; (3) the number of communication rounds for signing a message; (4) the time complexity for signing a message; (5) the amount of communication for signing a message; (6) the time complexity for verifying a multisignature; (7) the length of the resulting multisignatures. Existing multisignature schemes achieve various trade-offs among these measures, but none of them can achieve simultaneously the desired properties with respect to all (or even most) of these measures. In this paper, we present a novel multisignature scheme that offers desired properties with respect to the above (1)-(7) simultaneously, except that it uses random oracles (which however are often required in order to design practical schemes). In particular, our scheme is featured by its weak operational (i.e., plain public-key) model, non-interactive signing, and efficient verification.     

Hybrid proxy multisignature: A new type multi-party signature

In this paper, we introduce a new type of multi-party signature: hybrid proxy multisignature (HPM). An HPM is collaboratively generated by some signers themselves and some proxy signers on behalf of their original signers. We describe the syntax of general HPM schemes and formalize a notion of security for them. We also construct a concrete HPM scheme and prove its security in the Random Oracle Model, assuming the Co-Diffie-Hellman problem in the underlying groups equipped with a pairing is hard. The size of an HPM in our scheme is independent of the number of the actual signers. Further, the scheme has accountability, that is the signers of an HPM can be identified. Comparing with other types of multi-party signatures such as multisignature, proxy multisignature and multiproxy multisignature, HPM has more flexibility.     

新的ElGamal型广播多重数字签名方案

目前,所有的ElGamal型广播多重数字签名方案都存在一个问题：签名时需要签名者之间或签名者与签名收集者之间交换多次数据以获取同一签名参数,从而导致系统的通信量增大,且易受攻击。该文给出了一种新的基于离散对数问题的广播多重数字签名方案。该方案不需要签名者在签名时多次交换数据以获取同一参数,因此具有更高的实用性和安全性。     

-一种安全的椭圆曲线多重数字签名方案

现有的椭圆曲线数字签名方案ECDSA不适合进行多重数字签名，文章对ECDSA方案稍作了改进，给出一种安全性建立在椭圆曲线离散对数难题（ECDLP）上的、适合多重数字签名的椭圆曲线数字签名方案，然后在此基础上提出一种安全性建立在ECDLP上的多重数字签名方案，分析表明这两种方案都正确并且能够有效抵抗攻击。     

混合结构的数字多重签名算法

分析了一种比较普遍的混合签名结构,提出一种安全高效的归一化结构多重数字签名算法。该方法将广播结构签名虚拟成有序节点,并引入了一个签名验证中心(CSV)参与运算。对比测试表明,该算法安全性和效率都较高,能够解决多种多重结构的数字签名。     

Weaknesses in some multisignature schemes for specified group of verifiers

The author points out that Laih and Yen's multisignature scheme and Hwang, Chen and Chang's multisignature scheme do not satisfy their security requirements.     

基于XML文档划分的群体签名模式研究

本文在Chang的群体签名方案的基础上利用XML的逻辑结构提出一种有效的文档划分方法,从而给出了一种XML 群体签名方案,该方案符合XML签名标准以便于实际应用。