查询词典 cryptographic

Provable Security is a formal method for proving the security of cryptographic schemes, in which the difficulty of breaking a particular scheme is formally related to that of solving a widely believed computational hard problem. Provable security has already become an important theme of theoretical researches in modern cryptography. This dissertation investigates the provable security of public-key encryptions and hybrid encryptions of asymmetric and symmetric encryptions. This includes the various formal security notions and the constructions can be proved to achieve them. Among the constructions, hybrid encryptions are themselves an important way to obtain public-key encryption schemes with chosen ciphertext security. The main results are as follows:(1) The one-wayness of the trapdoor one-way function in NTRU depends on the randomness of the session key, which is different from previous ones. Based on this observation, a new kind of trapdoor one-way function, trapdoor one-way functions with an auxiliary random variable is proposed.

可证明安全性是一种证明密码学方案安全性的形式化方法，它将密码学方案的安全性归约为公认的计算难题，已成为现代密码学领域中理论工作的主线，本文主要研究公钥加密与单双钥混合加密的可证明安全性，这包括它们的各种形式化安全性定义以及达到这些安全性定义的方案构造，而单双钥混合加密本身也是一种构造选择密文安全公钥加密的重要方法，本文得到的主要结果如下：(1)在研究NTRU公钥加密的特殊性基础上，对于公钥加密的陷门单向函数加密模型进行了扩展，提出了具有辅助陷门单向函数的概念，并将其扩展到多元的情况，讨论了可能的密码学用途。

Arxan Technologies, Inc., of Bethesda, Maryland, has launched a new cryptographic key protection technology.

Arxan技术公司开发了一个新的密码钥匙保护技术。

In this paper, we propose a new visual cryptographic method for gray-level and chromatic images without pixel expansion. We simultaneously encrypt m successive pixels (called an "encryption sequence") each time in accordance with two basis matrices. In every m encryption sequences with b blacks, we make sure that b encryption sequences are encoded by black basis matrix, and the other ones are encoded by white basis matrix.

本研究提出一种不需要像素扩展的灰阶和彩色视觉密码的技术；我们的方法利用多点同时加密的概念，每次取连续的 m 个点做为加密序列进行加密，我们的方法可以确保在 m 个具有 b 个黑点的加密序列中，一定会有 b 个加密序列是使用黑点基础矩阵加密，另外的个则使用白点基础矩阵加密，因此在叠合影像上黑与白的变化很规律。

Bounded one-way function is a new cryptographic primitive proposed for the foundation of practical cryptography.

有界单向函数是一个新的密码学概念。有界单向函数是为了研究设计更为灵活、更实用的密码系统的基础而提出的。

The braid group is infinite non-commutative group, and it has many hard problems that can be utilized to design cryptographic primitives, such as the word problem, conjugacy problem and root problem.

辫群是一种非交换的无限群，该群中有许多困难问题是不可解的，如字问题、共轭问题和根问题等，利用这些困难问题可以去设计一些密码协议。

However, one of the key of the art on cipher is the security analysis on cryptographic functions.

而密码技术的关键性问题之一在于密码函数的安全性分析。

After deeply analyzing the universally composable security, we defined the level of different ideal functionalities for the same cryptographic task, and pointed out the rationality in defining the levels of ideal functionalities.

针对以上问题，在对任意组合安全理论进行深入分析后，本文给出了同一密码原语不同理想功能之间安全等级的定义，并说明了这种定义的合理性，从而刻画了同一密码原语的不同理想功能之间的关系。

Cryptographic algorithm and key are the very important part of cryptogram technology.

密钥和密码算法的安全是密码卡的核心和关键。

This paper proposes the research situation of the programmable cryptographic technique and the charac teristics of the programmable cryptograph,including the aspects to be concerned about in the development of the programmable cryptograph.

文中给出了可编程密码技术的研究现状，可编程密码的特点，及在开展可编程密码研究时应注意的问题。

In fact, standards working groups such as the one that produced the WEP standard often include a lot of very smart technologists, but not a single cryptographer, despite the fact they intend to develop security standards that rely explicitly on cryptographic algorithms.

事实上，在标准工作组，如一个产生了WEP标准的，往往包括了很多很聪明的技术人员，而不仅仅有一个译解密码者，尽管事实上他们打算制定的安全标准，很晃显地依赖加密算法。

Bob Eckert has been chairman and chief executive of Mattel for eight years.

美泰董事长兼首席执行官鲍勃·埃克尔特在任已8年。

The outlook for honors and disgraces carries on and surpasses the traditional outlook for honors and disgraces theoretically, and carries on and develops the theory of construction of socialist mora...

社会主义荣辱观的提出在理论上是对传统荣辱观的一次继承和超越，是对社会主义道德建设理论的继承和发展，在实践上有利于形成良好的社会风尚。