【作者】 谷科；

【导师】 贾维嘉；

【作者基本信息】 中南大学 ， 计算机科学与技术， 2012， 博士

【摘要】 数字签名技术作为信息安全领域内的重要技术手段,为其他领域内的许多应用提供着身份认证、数据完整性保护以及数据不可否认性等服务,是在整个信息领域内建立完整的安全机制所不可缺少的基本手段。而随着基于公钥密码体制的数字签名技术的发展,对密钥的管理已经成为推动数字签名技术广泛应用的关键,如何能够简化密钥的管理已成为数字签名技术发展的一个方向。所以,基于身份的数字签名技术被提出。基于身份的数字签名技术可以看成是基于公钥密码体制的数字签名技术的扩展,是基于身份的密码体制与传统的数字签名技术的结合体。与基于公钥密码体制的数字签名技术相比,基于身份的数字签名技术简化了密钥的管理工作。目前,如何安全地把基于公钥密码体制的数字签名方案转换到基于身份的密码体制下或者提出新的基于身份的数字签名方案已成为学者研究数字签名技术的一个热点。因此,根据目前基于身份的数字签名技术研究现状,本文主要研究在标准模型下基于身份的数字签名方案及其变种方案,包括标准的基于身份的签名方案,基于身份的代理签名方案,基于身份的多代理签名方案以及基于模糊身份(属性)的签名方案。具体工作如下：(1)在Paterson方案的基础上,提出一个在标准模型下更高效的基于身份的签名方案。该方案采用转变原方案中的群元素乘法运算为整数加法运算的方法来提高计算效率,而且利用在线／脱线处理预先计算的方法来改进方案的在线计算性能。与现有的在标准模型下基于身份的签名方案相比,本文方案的计算效率更高。(2)提出一个基于身份的代理签名框架以及一个详细的安全模型,同时提出一个在标准模型下基于身份的代理签名方案。比较于已有的基于身份的代理签名安全模型,本文引入了Boldyreva等人最近提出的代理签名安全模型和Schuldt等人的工作到安全模型中,本文提出的安全模型考虑了自我代理签名的情况和暴露代理签名私钥的情况。同时,本文提出的基于身份的代理签名方案是在标准模型下被构建,比较于其他的在标准模型下基于身份的代理签名方案,本文提出的方案更加有效。(3)在已经提出的多代理签名可证安全模型的基础上,针对n+1个用户提出一个基于身份的多代理签名框架和一个广义的可证安全模型(n为参与签名的代理者数目)。在本文的安全模型中,敌手的优势被最大化的定义,用户间的交互行为能被完整的分析,并且引入了Boldyreva等人最近关于代理签名的研究工作以及Schuldt等人的工作。同时,对Paterson等人提出的基于身份的签名方案进行扩展,提出一个在标准模型下基于身份的多代理签名方案。此外,本文在基于身份的多代理签名方案和安全模型的基础上,提出一个在标准模型下基于身份的门限代理签名方案和一个相应的安全模型。(4)在Maji等人提出的签名框架基础上,提出一个简化的基于属性的签名框架,同时展示一个详细的安全模型。并且,在本文的签名框架下,提出一个完全安全的(适应性的选择谓词不可伪造性和完全隐私性)在标准模型下基于属性的签名方案,该方案能够在访问结构上支持单调的谓词逻辑。相比较Maji等人在通用群模型下提出的方案,本文的方案构建在标准模型下,同时比较Okamoto等人提出的方案,本文的方案通过减少计算消耗使得方案更有效。更多还原

【Abstract】 As an important technology of information security, digital signature may provide many services for other applications, which include identity authentication, data integrity protection, data non-repudiation and so on. Also, with the development of digital signature based on public key cryptography, key management has been an important basis for promoting the application of digital signature. Thus, based on identity-based cryptography, identity-based signature (IBS) is proposed. IBS is a variant of digital signature based on public key cryptography, which is a combination of digital signature and identity-based cryptography. Comparing with digital signature based on public key cryptography, IBS can simplify key management and be more easily used for many applications.Then, how to convert a public-key-based signature scheme to an identity-based signature scheme or construct a new identity-based signature scheme has been a hot research orientation. According to the current research about IBS, we focus on identity-based signature schemes and variant schemes in this paper, which include identity-based signature schemes, identity-based proxy signature schemes, identity-based multi-proxy signature schemes and attribute-based (fuzzy identity-based) signature schemes. Our works are as follows:(1)We show a more efficient identity-based signature scheme based on Paterson’s scheme in the standard model. The scheme improves computational efficiency by changing multiplicative operation to addition operation. Comparing with Paterson’s scheme, our scheme decreases the number of multiplicative operation. Also, comparing with other identity-based signature schemes in the standard model, our scheme is more efficient.(2)We present a framework for identity-based proxy signature (IBPS), and show a detailed security model for IBPS. Comparing with the existing security models for IBPS, we introduce Boldyreva’s model and Schuldt’s work to our security model. We further strengthen our security model by considering self-proxy signing and exposure arbitrary proxy signing keys. Also, we present a fully secure (adaptive-identity unforgeable) IBPS scheme in the standard model. Comparing with other IBPS schemes in the standard model, the proposed scheme decreases the computation cost.(3)Based on the existing security models for multi-proxy signature, we present a generalized signature framework and a complete security model for identity-based multi-proxy signature on n+1users, where n is the number of proxy signers participating in signing. In our security model, adversary’s ability is maximized. Also, Boldyreva’s model and Schuldt’s work are introduced to our security model. Additionally, a new identity-based multi-proxy signature scheme is proposed in the standard model, which is based on Paterson’s scheme. Then, based on the proposed identity-based multi-proxy signature scheme and its security model, we presenet an identity-based threshold-proxy signature scheme in the standard model and a corresponding security model.(4)We present a framework for attribute-based signature (ABS), which is based on Maji’s framework, and show a detailed security model for ABS. In our framework for ABS, we present a fully secure (adaptive-predicate unforgeable and perfectly private) ABS scheme for monotone predicates over access structure. Comparing with Maji’s third instantiation in the generic group model, the proposed scheme is constructed in the standard model and is efficient. Furthermore, comparing with the simple form of Okamoto’s scheme in the standard model, the proposed scheme is more efficient by employing more simple standard assumption and decreasing the computation cost.更多还原