基于访问结构的数据加密与共享协议的研究

发布时间：2018-04-01 21:40

本文选题：秘密共享　切入点：星拓扑加密　出处：《北京邮电大学》2017年博士论文

【摘要】：随着开放式网络环境的发展,用户信息泄露的风险不断增加。其安全威胁主要来源于未经授权的用户对隐私数据的非法访问。因此,在数据加密系统中完善对用户访问权限的控制是解决用户隐私泄露问题的关键。本文主要围绕基于访问结构的数据加密与共享协议展开研究:针对密钥管理问题提出秘密共享方案;针对数据本身的保密性提出不同访问结构下的加密方案,其中主要研究方案的构造思想、数学平台及相应的难题假设。通过分析已有的经典攻击算法和量子攻击算法,将交换代数结构下的加密体制推广到了非交换代数领域中得到一些抵抗量子攻击算法的加密方案。本文主要取得如下研究成果:(1)针对密钥管理构造了一种无可信第三方的秘密共享方案,该方案无需借助可信第三方来完成秘密分发,同时支持任意分发者的多秘密分享。方案实现了门限结构和敌手结构,在实际应用中可以规定某些参与者集合为非授权子集,提供了访问秘密的灵活性。进一步,参与者在生成秘密重构份额的同时构造了秘密验证份额,利用拉格朗日插值算法的加法同态性使得方案具有预验证功能。即参与者在重构秘密前能够验证彼此份额的真实性。最后,基于抗碰撞哈希函数实现了方案的动态性,即方案允许参与者动态地加入和退出而不影响安全性。(2)针对局域网数据保密需求,基于非交换代数结构设计了一个新的对称加密框架——星拓扑加密,该体制涉及到一个中心服务器和多个用户,用户可以独立地与中心服务器进行交互。方案中每个用户只需持有一个解密密钥,该方案实现了高效的多对一对称加密模式。方案具有匿名性、可验证性以及不可否认性,其安全性依赖于非交换群分解难题。该方案可以应用于商务对话、医疗服务等系统。(3)针对Cramer-Shoup公钥加密体制的非交换模拟,Vasco M等人在TCC'05年会上提出一个公开问题,即如何基于非交换代数结构设计选择密文攻击模型下可证明安全的加密方案。本文首先定义了作用可换集族的概念,并结合Cramer-Shoup密码体制提出新加密框架,同时给出该框架在标准模型自适应选择密文攻击下的安全性证明方法。进一步,对非交换代数结构中的判定型难题假设进行研究,定义了判定型非交换群分解问题及共辗搜索问题。此外,利用该框架构造了基于切比雪夫多项式的混沌加密方案,即方案达到了自适应选择密文攻击模型下不可区分性,从而回答了 Liao X等人提出的问题。(4)针对多对多的加密模式,本文围绕属性基加密体制展开分析,以提高属性基加密方案的效率为目标,提出一个高效的外包属性基加密方案。该方案利用一种盲化技术对加密算法中的秘密随机数进行盲化。加密用户持有外包密钥(即加密转换密钥)将加密过程中高复杂度的模指数运算外包给云服务器,解密算法利用了 Green外包解密技术来实现。方案的优势在于同时将加、解密算法的模指数运算降低到常数级。此外,方案利用哈希函数实现了可验证性,即解密用户能够检验云服务器行为的诚实性以及消息的真实性。(5)针对密文的可操作性,本文重点研究了全同态加密体制。通过噪声管理机制对已有全同态方案进行分类,讨论了基于噪声的构造技术和无噪声构造技术。进一步提出一个新的无噪声全同态加密框架,同时给出安全性分析。最后深入研究了几类典型的无噪全同态加密方案并得出结论:多数无噪声全同态方案均受到线性攻击。
[Abstract]:With the development of the open network environment, the risk of disclosure of user information is increasing. The main source of security threats from illegal access by unauthorized users of data privacy. Therefore, the data encryption system to improve access to the user is the key to solving the problem of the leakage of user privacy. This paper mainly focuses on the access structure data encryption and sharing protocol research for key management problems based on secret sharing scheme; according to the confidentiality of the data itself encryption scheme is proposed under different access structure, the idea of constructing research program in which the assumption of mathematical platform and the corresponding problems. Through the classical attack algorithm and quantum attack algorithm for the analysis of existing switching algebra the structure of the encryption system to get some resistance quantum attack algorithm encryption scheme for non commutative algebra field in this paper. Research results are as follows: (1) to construct key management secret sharing scheme without a trusted third party, the scheme without the trusted third party to complete the secret distribution, and support multi secret sharing scheme. The arbitrary distribution of threshold structure and adversary structure, can provide some set of participants for non authorized subset in the practical application, provides access to secret flexibility. Further, the participants constructed the secret authentication share in the generation of secret reconstruction share at the same time, using the addition of homomorphic Lagrange interpolation algorithm which makes the scheme has pre verification function. The participants can verify the authenticity of each share in secret before reconstruction. Finally, a collision resistant hash function of the realization of the dynamic scheme based on the scheme allows participants to dynamically join and exit without compromising security. (2) according to the LAN data security needs For non commutative algebraic structure to design a new symmetric encryption framework based on star topology, the system relates to a central server and a plurality of users, users can independently interact with the central server. For each user only needs to hold a decryption key, the scheme achieves more efficient for a symmetric encryption scheme with anonymity model., verifiable and non repudiation, its security depends on the non commutative group decomposition problem. The scheme can be applied to business conversation, medical service system. (3) for non commutative Cramer-Shoup public key encryption system simulation, Vasco M proposed an open the problem at the TCC'05 annual meeting, which is how to exchange encryption scheme based on non chosen ciphertext attack model algebraic structure design provably secure. This paper defines the role for family concept, and combined with Cramer-Sho Up cryptosystem proposed a new encryption framework, and gives the framework selection of safety proof method of ciphertext attack in the standard model of non adaptive. Further, to determine the type of algebraic structure in the problem of exchange hypothesis research, defines the decision type non commutative group decomposition problem and rolling search problem. In addition, the use of the framework is constructed chaotic encryption scheme based on Chebyshev polynomial, the scheme can achieve the adaptive chosen ciphertext attack model indistinguishability, which answer the Liao proposed by X et al. (4) based on multi encryption mode, this paper analyzes the attribute based encryption system, the encryption scheme to improve the efficiency of attribute based as the goal. An efficient encryption scheme is proposed. The scheme of outsourcing attribute based blind random number of secret encryption algorithm using a blind encryption technology. The user holds the key of outsourcing (i.e. encryption conversion key) encryption process will be highly complex modular exponentiation of outsourcing to the cloud server, decryption algorithm using Green outsourcing decryption technology to achieve. The advantage of the scheme, reduce the modular exponentiation decryption algorithm to a constant level. In addition, the scheme using hash function verification, the user can decrypt the validation of cloud server behavior and message integrity. (5) according to the ciphertext operability, this paper focuses on the research of fully homomorphic encryption system. The noise management mechanism of existing schemes for fully homomorphic classification, discusses the construction technology of noise and no noise. Based on further construction technology a new noise free fully homomorphic encryption framework, and give the security analysis. Finally, in-depth study of the noise free fully homomorphic encryption scheme and concludes several typical noise: most of all the same The state schemes are all subjected to linear attacks.

【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TP309.7

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