抗泄漏密码学关键技术研究

发布时间：2018-11-09 10:23

【摘要】：密码系统在实际环境中运行时通常会受到攻击者的物理攻击,为了抵抗这类攻击所带来的危害,抗泄漏密码学应运而生。在它所考虑的场景中,敌手可以额外的获取关于密码系统内部执行状态的泄漏信息,因此构造在此环境下安全的密码学方案与构造传统密码学方案比起来更具挑战性。尤其是当敌手可以持续的获得有关内部状态的泄漏信息时,也就是说模型中并不对敌手可以获得的总信息量做预先限制时,构造相应的密码方案的任务将变得非常困难。因此,我们需要发展新的技术来解决这个问题。在本文中,我们将重点关注于哈希证明系统这一技术手段,并研究如何发展并利用这一技术,以达到在连续内存泄漏场景中构造公钥加密方案的目的。哈希证明系统是无泄漏场景和有界泄漏场景中构造公钥加密方案的一个最基本的工具。然而,目前还不清楚如何利用哈希证明系统去在连续泄漏场景下构造公钥加密方案。在本文中,我们将引入哈希证明系统的一个变形——可更新哈希证明系统,并利用这个新的工具来解决连续泄漏场景下公钥加密方案的构造问题。顾名思义,可更新哈希证明系统即为拥有私钥更新能力的哈希证明系统,除此之外,我们还要求其在连续内存泄漏场景下可以保持哈希证明系统的一些良好的性质。可以看到,可更新哈希证明系统非常适合于在连续内存场景下构造具有不同安全等级的公钥加密方案,并且可以基于一些常见的假设实例化。我们的贡献主要包括以下三个方面：首先,我们提出的新工具,可更新哈希证明系统,为连续内存泄漏场景下公钥密码学的构造带来了新的视角,并为一些已有的方案带来了新的解读。其次,我们发现,对几乎所有已知的基于哈希证明系统的公钥加密方案来说,仅仅通过简单的将方案中的哈希证明系统替换为可更新哈希证明系统,就可以在保持方案原有安全属性不降低的情况下将方案升级为可以抵抗连续内存攻击的方案。这里需要指出的是,连续内存泄漏的抵抗完全来自与可更新哈希证明系统本身,而且整个方案的结构保持不变,这也为密码系统的升级带来了极大的便利。最后,我们发现,可以基于双线性群上的常用假设对可更新哈希证明系统进行实例化。而且,实例化后的方案具有很高的效率。特别的,就连续内存泄漏场景下选择密文安全的公钥加密方案来说,本文中所提出方案的效率要远远的优于已有的方案。
[Abstract]:In order to resist the harm caused by this kind of attack, the anti-disclosure cryptography comes into being in order to resist the physical attack of the cryptosystem when it runs in the real environment. In the scenario under consideration, the enemy can obtain additional information about the internal execution state of the cryptographic system, so it is more challenging to construct a secure cryptographic scheme in this environment than to construct a traditional cryptographic scheme. Especially when the enemy can continuously obtain information about the internal state, that is, the model does not pre-limit the total amount of information the enemy can obtain, the task of constructing the corresponding cryptographic scheme will become very difficult. Therefore, we need to develop new technology to solve this problem. In this paper, we will focus on the hashing proof system as a technical means, and study how to develop and utilize this technique to construct a public-key encryption scheme in a continuous memory leak scenario. The hash proof system is a basic tool for constructing public key encryption schemes in undisclosed and bounded leak scenarios. However, it is not clear how to use the hash proof system to construct a public key encryption scheme in a continuous leak scenario. In this paper, we will introduce a variant of the hash proof system, the updatable hash proof system, and use this new tool to solve the problem of constructing a public-key encryption scheme in a continuous leak scenario. As the name implies, the updatable hash proof system is a hash proof system with the ability to update the private key. In addition, we also require it to maintain some good properties of the hash proof system in a continuous memory leak scenario. It can be seen that the updatable hash proof system is very suitable for constructing public key encryption schemes with different security levels in continuous memory scenarios and can be instantiated based on some common assumptions. Our contributions mainly include the following three aspects: firstly, our new tool, the updatable hash proof system, provides a new perspective for the construction of public key cryptography in a continuous memory leak scenario. And for some of the existing programs to bring a new interpretation. Secondly, we find that for almost all known public key encryption schemes based on hash proof systems, we simply replace the hash proof system in the scheme with an updatable hash proof system. The scheme can be upgraded to a scheme that can resist continuous memory attack without lowering the original security properties of the scheme. It should be pointed out here that the resistance to continuous memory leakage comes entirely from the updatable hash proof system itself, and the structure of the whole scheme remains unchanged, which also brings great convenience to the upgrade of the cryptographic system. Finally, we find that we can instantiate the updatable hash proof system based on the common assumptions on bilinear groups. Moreover, the instantiated scheme has a high efficiency. In particular, the efficiency of the scheme proposed in this paper is far better than that of the existing scheme for the selection of ciphertext secure public key encryption schemes in continuous memory leak scenarios.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN918.1

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