超前向安全数字签名理论及其应用的研究

The problem of key exposure threatens the security of digital signatures greatly. Reducing the damage of key exposure for digital signatures is an important research. Designing digital signatures beyond forward security is an effective method to deal with this problem. Digtial signatures beyond forward security can keep the security of signatures not only previous to key exposure, but also after key exposure. This project will research on the theory of digital signatures beyond forward security and their application. Our researches include the following aspects. In order to deal with the problem that key-insulated signatures greatly depend on the security of external device, we will research on new methods of defending the key exposure of external device. Based on new methods and strategies, design intrusion-resilient signature schemes in which all performance parameters are not more than O(logT) and prove their security in the standard model. Considering key leakage and key exposure simultaneously, we will introduce the leakage resilient property into signatures beyond forward security to construct leakage-resilient signature schemes beyond forward security, and give the formal security model and security proof. Research on how to apply the intrusion-resilient property to all kinds of digital signatures with special properties and their generic constructions.

密钥泄露问题严重威胁着数字签名的安全性，减小密钥泄露对数字签名的危害是一项重要的研究工作。超前向安全数字签名是一种有效的解决方法，它不仅能保护密钥泄露之前，还能保护密钥泄露之后签名的安全性。本课题将对超前向安全数字签名理论及其应用进行研究，具体包括：针对密钥隔离签名过多依赖外围设备安全性的问题，在不增加外围设备数量的条件下，研究可抵御外围设备密钥泄露的新方法；基于新的方法、策略，设计各性能参数复杂性均不超过O(logT)的入侵容忍签名方案，并在标准模型下证明其安全性；同时考虑密钥泄漏(leakage)和密钥泄露(exposure)问题，将泄漏容忍性质引入到超前向安全签名体制中，构造泄漏容忍超前向安全签名方案，给出形式化的安全性模型和安全性证明；研究入侵容忍性质在各类特殊性质数字签名中的应用，并研究其通用的构造方法。

密钥泄露问题严重威胁着数字签名的安全性，减小密钥泄露对数字签名的危害是一项重要的研究工作。超前向安全数字签名是一种有效的解决方法，它不仅能保护密钥泄露之前，还能保护密钥泄露之后签名的安全性。本课题将对超前向安全数字签名理论及其应用进行研究，具体包括：针对密钥隔离签名过多依赖外围设备安全性的问题，在不增加外围设备数量的条件下，研究可抵御外围设备密钥泄露的新方法；基于新的方法、策略，设计各性能参数复杂性均不超过O(logT)的入侵容忍方案，并在标准模型下证明其安全性；构造抵御密钥泄露的超前向安全签名方案，给出形式化的安全性模型和安全性证明；研究各类特殊性质超前向安全数字签名，以及在云计算中的应用。