一种基于Pairing的带有阈下信道的灵活数字签名方案

阈下信道是一种在公开信道中所建立的实现隐蔽通信的信道,它是一种典型的信息隐藏技术.通过结合数字签名和阈下信道技术,提出了一种基于双线性对的具有阈下信道的数字签名方案,并且在随机预言模型下证明该方案是安全的,其安全性是基于求解有限域上离散对数的困难性.该方案的一个主要特点是:同一个签名算法能够产生普通数字签名和具有阈下信道的数字签名,在正常情况下,签名者可以进行一般数字签名,如果需要阈下信道通信,签名者能够产生带有阈下信道的数字签名,非常方便签名者对阈下信道签名的灵活使用.     

封闭计算机网络中阈下信道的若干方案

１９８３年，Ｓｉｍｍｏｎｓ［１］提出了阈下信道的概念，并阐述了如何在一个可认证的消息中隐藏一个秘密信息。１９８５年，Ｓｉｍｍｏｎｓ［２］又指出如何利用ＥｌＧａｍａｌ签名方案建立阈下信道。本文中，我们利用零知识证明方法，尝试法和盲签名方法在一些特殊的ＥｌＧａｍａｌ型签名方案上建立了三个抗阈下信道签名方案。     

封闭阈下信道的若干新型签名方案

1983年,Simmons[1]提出了阈下信道的概念,并阐述了如何在一个可认证的消息中隐藏一个秘密信息。1985年和1994年,Simmons分别描述了如何利用EIGamal签名方案和DSS建立阈下信道并指出了阈下信道的若干应用[2-5],1998年笔者在参考文献[6]中建立了三个封闭阈下信道的签名方案。该文又利用有向签名、代理签名和多重签名方法建立了三个封闭阈下信道签名的新型方案。     

DSS数字签名在阈下信道中的应用

阈下信道是一种典型的现代信息隐藏技术,在信息安全方面有着广阔的应用前景.文章给出了数字签名标准的原理及阈下信道的概念、模型、分类等基本知识,并讨论了DSS数字签名中的阈下信道及其应用,对阈下信道及其相关信息给出了较为全面的说明.     

以图像为掩护媒体的阈下信道抗干扰性

为了增强秘密信息传输的安全性，利用阈下信道进行通信是一种可行的方法，提出了阈下信道的通信系统模型，阈下信道的分类、分析了阈下信道抗干扰性应研究的内容，并以图像为例研究了其作为阈下信道的信息载体的抗干扰性，提出了一种基于行列式计算思想的图像置乱算法，研究表明该算法用于秘密信息的嵌入，其抗干扰性较好。     

代理签名与阈下信道的封闭

1983年,Simmons1提出了阈下信道的概念,并阐述了如何在一个可认证的消息中隐藏一个秘密信息.1985年和1994年,Simmons分别描述了如何利用ElGamal签名方案和 DSS建立阈下信道并指出了阈下信道的若干应用2－3,1998年和2000年笔者分别在文献4和文献5中共建立了六个封闭阈下信道的签名方案.文章将基于代理多重签名和一次性代理签名又建立了两个封闭阈下信道的新型签名方案.     

代理签名与阈下信道的封闭

１９８３年,Ｓｉｍｍｏｎｓ＾［１］提出了阈下信道的概念,并阐述了如何在一个可认证的消息中隐藏一个秘密信息,１９８５年和１９９４年,Ｓｉｍｍｏｎｓ分别描述了如何利用ＥｌＧａｍａｌ签名方案和ＤＳＳ建立阈下信道并下阈下信道的若干应用＾［２－３］,１９９８年和２０００年笔者分别文献［４］和文献［５］中共建立了六个封闭阈下信道的签名方案,文章将基于代理多重签名和一次性代理签名又建立了两个封闭阈下信道的新型签     

一种基于CPK数字签名的阈下信道

阈下信道是一种信息隐藏技术,能够在数字签名的过程中传输秘密信息,这为认证、防伪等方面的应用提供了一种实现平台。在CPK数字签名的基础上提出一种阈下信道,加大CPK体制的应用。     

一种基于CPK数字签名的阈下信道

阈下信道是一种信息隐藏技术，能够在数字签名的过程中传输秘密信息，这为认证、防伪等方面的应用提供了一种实现平台。在CPK数字签名的基础上提出一种阁下信道，加大CPK体制的应用。     

椭圆曲线有序多重签名中阈下信道及封闭方法

阈下信道是在正常公开信道的通信模式下所建立的一种传递隐藏信息的秘密信道。以一种基于椭圆曲线密码体制的有序多重签名算法为例,对其中存在的宽带和窄带阈下信道进行了具体分析,并提出一种基于承诺掩蔽的阈下信道封闭方案,并对该方案的安全性和可行性进行了理论分析和探讨。     

A traceable E-cash transfer system against blackmail via subliminal channel

Due to the development of Internet communication technology, E-Commerce is becoming popular. Because crime is thriving, avoiding malicious behavior and protecting property becomes an important issue. To prevent malicious behavior, many proposals have been put forth. The subliminal channel is the most popular method, which notifies the designated receiver to transmit secret messages. Simmons was the first to propose this concept in 1983. Now, more and more digital signature applications use a subliminal channel to transfer secret messages. In this paper, we propose a traceable E-cash transfer system against blackmail via subliminal channel.     

网络秘密信道机理与防范

阐述了网络秘密信道的通信系统模型，提出了秘密信道的分类方法，深入研究了建立网络秘密信道的机理，并指出了基于数字水印技术和阈下通道技术建立网络秘密信道的可行性。对典型的建立网络秘密信道的工具作了仔细剖析，并在此基础上给出了有效的应对策略。     

面向无人机空地通信的无线信道密钥生成技术研究

无人机(unmanned aerial vehicles,UAVs)部署为空中通信节点为地面用户提供服务是未来非常具有吸引力的通信手段,基于信道密钥生成的方式可用于解决无线通信的安全问题.但空地信道的信道特征在短时间内互易性不佳的特点,会导致信道密钥生成性能急剧下降.针对这一问题,本文针对无人机测控单载波频域均衡(si...     

未知信道中的信息隐藏容量

随着计算机技术和网络的不断发展，人们对于版权保护和身份认证的需求不断增长，信息隐藏技术的重要性日渐显现。如果把信息隐藏看作通信过程，由于信道错误和恶意攻击的存在，信息的发送方和接收方通常均无法完全了解这一通信信道的所有特性，这为估计信息隐藏的容量带来了不少困难，从而影响了信息隐藏技术的进一步发展。该文针对信道错误和恶意攻击提出了一种估算信息隐藏容量的数学模型，该模型可以较好地抵抗一般的攻击和信道错误对信息传输造成的影响，从而为信息隐藏提供了理论依据。该文分析了信息隐藏容量的上下界，仿真结果表明这一方法具有较好的实用性。     

Observable behavior of distributed systems: Component reasoning for concurrent objects

Distributed and concurrent object-oriented systems are difficult to analyze due to the complexity of their concurrency, communication, and synchronization mechanisms. Rather than performing analysis at the level of code in, e.g., Java or C++, we consider the analysis of such systems at the level of an abstract, executable modeling language. This language, based on concurrent objects communicating by asynchronous method calls, avoids some difficulties of mainstream object-oriented programming languages related to compositionality and aliasing. To facilitate system analysis, compositional verification systems are needed, which allow components to be analyzed independently of their environment. In this paper, a proof system for partial correctness reasoning is established based on communication histories and class invariants. A particular feature of our approach is that the alphabets of different objects are completely disjoint. Compared to related work, this allows the formulation of a much simpler Hoare-style proof system and reduces reasoning complexity by significantly simplifying formulas in terms of the number of needed quantifiers. The soundness and relative completeness of this proof system are shown using a transformational approach from a sequential language with a non-deterministic assignment operator.     

Algorithm substitution attacks against receivers

This work describes a class of Algorithm Substitution Attack (ASA) generically targeting the receiver of a communication between two parties. Our work provides a unified framework that applies to any scheme where a secret key is held by the receiver; in particular, message authentication schemes (MACs), authenticated encryption (AEAD) and public key encryption (PKE). Our unified framework brings together prior work targeting MAC schemes (FSE’19) and AEAD schemes (IMACC’19); we extend prior work by showing that public key encryption may also be targeted. ASAs were initially introduced by Bellare, Paterson and Rogaway in light of revelations concerning mass surveillance, as a novel attack class against the confidentiality of encryption schemes. Such an attack replaces one or more of the regular scheme algorithms with a subverted version that aims to reveal information to an adversary (engaged in mass surveillance), while remaining undetected by users. Previous work looking at ASAs against encryption schemes can be divided into two groups. ASAs against PKE schemes target key generation by creating subverted public keys that allow an adversary to recover the secret key. ASAs against symmetric encryption target the encryption algorithm and leak information through a subliminal channel in the ciphertexts. We present a new class of attack that targets the decryption algorithm of an encryption scheme for symmetric encryption and public key encryption, or the verification algorithm for an authentication scheme. We present a generic framework for subverting a cryptographic scheme between a sender and receiver, and show how a decryption oracle allows a subverter to create a subliminal channel which can be used to leak secret keys. We then show that the generic framework can be applied to authenticated encryption with associated data, message authentication schemes, public key encryption and KEM/DEM constructions. We consider practical considerations and specific conditions that apply for particular schemes, strengthening the generic approach. Furthermore, we show how the hybrid subversion of key generation and decryption algorithms can be used to amplify the effectiveness of our decryption attack. We argue that this attack represents an attractive opportunity for a mass surveillance adversary. Our work serves to refine the ASA model and contributes to a series of papers that raises awareness and understanding about what is possible with ASAs.

     

三维统计信道中的多普勒效应及其信号分析

在三维(3 Dimensional,3D)空间域无线通信信道建模中,针对不同环境中仰角(Elevation Angle,EA)分布的复杂性,提出一种指数型概率分布,然后对这种分布下的无线信道进行建模,最后对接收端的多普勒功率谱密度(Power Spectral Density,PSD)和信号特性进行分析与仿真。采用近似算法推导出多普勒PSD的解析式,同时对Rayleigh 衰落信道中接收信号包络、平方包络的功率谱及时延相位差的概率密度函数进行研究。实验结果表明,所提出的三维无线信道模型在进行参数估计时符合相关理论与实际经验,同时指数函数模型的单变量特性使其在适应不同实际信道环境时非常灵活,因此可以对多种无线信道环境下的信道特征进行参数估计。