基于同态加密的移动代理主动保护算法

发布时间：2018-11-10 21:23

【摘要】：移动代理是一种新的适合大规模分布式应用的智能程序,在主动网络、网络管理、电子商务等领域有着广阔的应用前景。目前,移动代理的安全性是一个亟需解决的问题,如何保护移动代理不被恶意主机篡改及其所携带的信息不被泄漏是研究的难点。同态加密是基于数学难题,计算复杂性理论的密码学技术。它不同于传统的数据加密,允许在没有解密算法和解密密钥的条件下对加密的数据进行运算,解密后的结果和在明文状态下直接计算的结果相同。基于同态加密的移动代理保护方法是移动代理主动保护技术的一个有效手段。假设移动代理是由算术运算构成,如果有一个安全的同态加密方案能够实现所有运算的加密计算,则移动代理的保密计算问题将得到有效解决。目前,对同态加密的研究还处于起步阶段,存在以下不足:同态加密只限于对整数进行加密;对加密后的密文小数、大小和正负信息进行分析,有可能判断出明文小数、大小和正负信息,导致明文信息的泄漏。本文针对以上不足进行了研究,取得研究成果如下:提出基于ElGamal的实数定义域公钥同态加密算法。引入整数向实数同态映射的表示方法,实现了初等运算的保密计算,克服了加密后的密文会泄漏明文的小数、符号和大小关系的不足。该算法解决了EIGamal同态加密算法只能加密正整数的问题,可以抵抗已知明文攻击,不会泄漏小数和正负的信息,实现了非交互保密计算;提出了基于组合函数和加乘同态加密技术的移动代理保护策略。研究策略起源于由Sander和Tschudin提出的同态密码学思想,本文用组合函数和加乘同态方案来加密移动代理,加密的移动代理能够在任何主机上运行而不需解密,真正达到了移动代理的保护目的,并对方案的安全性进行了验证,证明了方案的可行性和有效性。
[Abstract]:Mobile agent is a new intelligent program suitable for large-scale distributed applications, which has a broad application prospect in active network, network management, electronic commerce and other fields. At present, the security of mobile agent is an urgent problem to be solved. How to protect mobile agent from malicious host tampering and the information it carries is difficult to be studied. Homomorphic encryption is a cryptographic technique based on mathematical problems and computational complexity theory. It is different from traditional data encryption and allows the operation of encrypted data without decryption algorithm and decryption key. The result after decryption is the same as that calculated directly in plaintext state. The method of mobile agent protection based on homomorphic encryption is an effective method for mobile agent active protection. Assuming that the mobile agent is composed of arithmetic operations, if there is a secure homomorphic encryption scheme that can realize the encryption computation of all operations, the secure computing problem of mobile agents will be solved effectively. At present, the research on homomorphic encryption is still in its infancy, which has the following shortcomings: homomorphic encryption is limited to integer encryption; By analyzing the decimal number, size and positive and negative information of encrypted ciphertext, it is possible to determine the decimal number, size and positive and negative information of plaintext, which leads to the leakage of plaintext information. The research results are as follows: a real number domain public-key homomorphic encryption algorithm based on ElGamal is proposed in this paper. The representation of integer to real homomorphism mapping is introduced to realize the secret calculation of elementary operation, which overcomes the deficiency that encrypted ciphertext will leak the decimal number, symbol and size relation of plaintext. This algorithm solves the problem that the EIGamal homomorphic encryption algorithm can only encrypt positive integers, can resist the known plaintext attacks, does not leak the information of decimal and positive and negative, and realizes the non-interactive security calculation. A mobile agent protection strategy based on combination function and multiplicative homomorphism encryption is proposed. The research strategy originates from the homomorphic cryptography thought proposed by Sander and Tschudin. In this paper, we use combination function and multiplicative homomorphism scheme to encrypt mobile agent, which can run on any host without decryption. The protection of mobile agent is achieved, and the security of the scheme is verified, which proves the feasibility and effectiveness of the scheme.
【学位授予单位】：沈阳航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP309.7

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