Based on the analysis of several typical zero-knowledge proof authentication protocols,this paper presents an authentication protocol with key-exchange function based on self-certified public key and zero-knowledge proof,which combines Girault's self-certified public key theory and the advantages of ECC.Analysis show that the scheme has higher security.Compared with the congeneric schemes,the proposed scheme is more efficient and has advantages in storage,communication overheads and computation cost.
As Zero-Knowledge proof plays a more and moreimportant role in modern cryptography, the need for formalanalysis becomes more urgent. In this paper, we make use offormal methods to establish a Zero-Knowledge result. The formalmodel is Probabilistic Applied Pi and the Zero-Knowledge proofis Hamiltonian cycle. By this example, our preliminary workshows how Zero-Knowledge can be modeled in formal modelssuch as process calculi and how to establish a Zero-Knowledgeproof by checking equivalence in the model.
A new scheme of dynamic group blind signature based on elliptic curve discrete logarithm problem (ECDLP) which extends the dynamic group blind signature and the knowledge signature to the elliptic curve cyclic group is generalized. The scheme runs in time slice manner and can be proved security with zero knowledge proof. It supports the dynamic addition and deletion of the group members freely. And the length of signature and computational effort for signing and verifying are independent on both the number of group members and the deleted members. So the security and efficiency are enhanced.
Most of the current trust models in peer-to-peer (P2P) networks are identity based, which means that in order for one peer to trust another, it needs to know the other peer's identity. In addition, the conventional access control mechanism is not suitable because the P2P networks is decentralize and dynamic one. We propose a neighborhood key method, authentication scheme base on zero-knowledge proof without leaking any sensitive information, each peer shares secrets only with authenticated neighbors, which generate verifiable pseudonym instead of their real identity from using a one-way Hash function. Security analysis proves that this method makes authentication can't be impersonated, while achieving better anonymity for peers, malicious peers cannot deduce a real identity. And also shows well defending man-in-middle attacks.
This paper presents the first type system for statically analyzing security protocols that are based on zero-knowledge proofs. We show how certain properties offered by zero-knowledge proofs can be characterized in terms of authorization policies and statically enforced by a type system. The analysis is modular and compositional, and provides security proofs for an unbounded number of protocol executions. We develop a new type-checker that conducts the analysis in a fully automated manner. We exemplify the applicability of our technique to real-world protocols by verifying the authenticity and secrecy properties of the Direct Anonymous Attestation (DAA) protocol. The analysis of DAA takes less than three seconds.
Lu Li, Jinsong Han, Yunhao Liu, Lei Hu · 7 authors
Most of the current trust models in peer-to-peer (P2P) systems are identity based, which means that in order for one peer to trust another, it needs to know the other peer's identity. Hence, there exists an inherent tradeoff between trust and anonymity. To the best of our knowledge, there is currently no P2P protocol that provides complete mutual anonymity as well as authentication and trust management. We propose a zero-knowledge authentication scheme called pseudo trust (PT), where each peer, instead of using its real identity, generates an unforgeable and verifiable pseudonym using a one-way hash function. A novel authentication scheme based on zero-knowledge proof is designed so that peers can be authenticated without leaking any sensitive information. With the help of PT, most existing identity-based trust management schemes become applicable in mutual anonymous P2P systems. We analyze the security and the anonymity in PT, and evaluate its performance using trace-driven simulations and a prototype PT-enabled P2P network. The strengths of our design include (1) no need for a centralized trusted party or CA, (2) high scalability and security, (3) low traffic and cryptography processing overheads, and (4) man-in-middle attack resistance.
提出了一种从3轮公开掷币的对任何NP语言的诚实验证者零知识证明系统到纯公钥模型下4轮(轮最优)对同一语言的具有并发合理性的并发零知识证明系统.该转化方法有如下优点:1) 它只引起O(1)(常数个)额外的模指数运算,相比Di Crescenzo等人在ICALP 05上提出的需要((n)个额外的模指数运算的转化方法,该系统在效率上有着本质上的提高,而所需的困难性假设不变;2) 在离散对数假设下,该转化方法产生一个完美零知识证明系统.注意到Di Crescenzo等人提出的系统只具有计算零知识性质.该转化方法依赖于一个特殊的对承诺中的离散对数的3轮诚实验证者零知识的证明系统.构造了两个基于不同承诺方案的只需要常数个模指数运算的系统,这种系统可能有着独立价值.;This paper shows how to efficiently transform any 3-round public-coin honest verifier zero knowledge argument system for any language in NP into a 4 round (round-optimal) concurrent zero knowledge argument for the same language in the bare public-key model. The transformation has the following properties: 1) incurs only O(1) (small constant, about 20) additional modular exponentiations. Compared to the concurrent zero knowledge protocol proposed by Di Crescenzo and Visconti in ICALP 2005, in which their transformation requires an overhead of ((n), the protocol is significantly more efficient under the same intractability assumptions; 2) yields a perfect zero knowledge argument under DL assumption. Note that the Di Crescenzo, et al.'s argument system enjoys only computational zero knowledge property. The transformation relies on a specific 3-round honest verifier zero knowledge proof of knowledge for committed discrete log. Such protocols that require only O(1) modular exponentiations based on different kinds of commitment scheme are developed and they may be of independent interest.
Richard Sinnott, David Chadwick, T. Doherty, David Martín · 8 authors
Grids allow for collaborative e-Research to be undertaken, often across institutional and national boundaries. Typically this is through the establishment of virtual organizations (VOs) where policies on access and usage of resources across partner sites are defined and subsequently enforced. For many VOs, these agreements have been lightweight and erred on the side of flexibility with minimal constraints on the kinds of jobs a user is allowed to run or the amount of resources that can be consumed. For many new domains such as e-Health, such flexibility is simply not tenable. Instead, precise definitions of what jobs can be run, and what data can be accessed by who need to be defined and enforced by sites. The role based access control model (KBAC) provides a well researched paradigm for controlling access to large scale dynamic VOs. However, the standard RBAC model assumes a single domain with centralised role management. When RBAC is applied to VOs, it does not specify how or where roles should be defined or made known to the distributed resource sites (who are always deemed to be autonomous to make access control decisions). Two main possibilities exist based on either a centralized or decentralized approach to VO role management. We present the advantages and disadvantages of the centralized and decentralized role models and describe how we have implemented them in a range of security focused e-Research domains at the National e-Science Centre (NeSC) at the University of Glasgow.
This article focuses on a kind of MP2P(Mobile P2P)network,a hybrid architecture,based on mobile computing,where the mobile terminals with Ad Hoc connections can communicate with each other via the P2P technology.The paper mainly makes a study on the secure communication in the mobile P2P network,with One-Round Zero-Knowledge Proofs for the identity authentication.Also the relative performances and efficiency of the system are discussed.
The recent development in the mobile technology (mobile phones, middleware, wireless networks, etc.) created a need for new methods of protecting the code transmitted through the network. The oldest and the simplest mechanisms concentrate more on integrity of the code itself and on the detection of unauthorized manipulation. The newer solutions not only secure the compiled program, but also the data, that can be gathered during its “journey,” and even the execution state. Some other approaches are based on prevention rather than detection. In this chapter we present a new idea of securing mobile agents. The proposed method protects all components of an agent: the code, the data, and the execution state. The proposal is based on a zero-knowledge proof system and a secure secret sharing scheme, two powerful cryptographic primitives. Next, the chapter includes security analysis of the new method and its comparison to other currently more widespread solutions. Finally, we propose a new direction of securing mobile agents by straightening the methods of protecting integrity of the mobile code with risk analysis and a reputation system that helps avoiding a high-risk behavior.Request access from your librarian to read this chapter's full text.
Exchange of attribute certificates is a means to establish mutual trust between strangers wishing to share resources or conduct business transactions. Automated trust negotiation (ATN) is a promising approach to regulating the exchange of sensitive information during this process. It has been a fundamental but challenging problem to preserve the privacy of the two negotiation parties during the period of ATN. We present the enhanced hidden credentials and improved concurrent zero-knowledge proof protocol. Based on the above technologies, we propose an ATN for e-business applications, named CASTLE. CASTLE can not only enable the oblivious and selective usage of an attribute or a certificate, but also be resistible for many attacks, especially conspiracy attack. We illustrate the usage of CASTLE through a typical example.
Chen Su, Tiejian Luo, Wei Liu, Jinliang Song · 5 authors
In an e-Science environment, large-scale distributed resources in autonomous domains are aggregated by unified collaborative platforms to support scientific research across organizational boundaries. In order to enhance the scalability of access management, an integrated approach for decentralizing the task from resource owners to administrators on the platform is needed. We propose an extensible access management framework to meet this requirement by supporting an administrative delegation policy. This feature allows administrators on the platform to make new policies based on the original policies made by resources owners. An access protocol that merges SAML and XACML is also included in the framework. It defines how distributed parties operate with each other to make decentralized authorization decisions.
SSO (single sign on) provides e-commerce users with easy access to applications and network resources, using a single, secure login identity. Web services (WS) based on SSO provide the potential to achieve interoperability of distributed electronic commerce (e-commerce) application integration among autonomous organizations, regardless of platforms, operating systems or languages. The most important challenge about the WS based on security SSO is the cost of implementation. After reviewing the paradigm of developing WS security standards and challenges, this paper presented a security model of JSON (JavaScript object notation) based on SSO architecture for e-commerce enterprise. The decentralized SSO security architecture is presented which is easy to integrate legacy system and new developed system.
The thesis is about a breadth-first exploration of logical concepts in cryptography and their linguistic abstraction and model-theoretic combination in a comprehensive logical system, called CPL (for Cryptographic Protocol Logic ). We focus on two fundamental aspects of cryptography. Namely, the security of communication (as opposed to security of storage ) and cryptographic protocols (as opposed to cryptographic operators ). The logical concepts explored are the following. Primary concepts: the modal concepts of belief, knowledge, norms, provability, space, and time. Secondary concepts: belief with error control, individual and propositional knowledge, confidentiality norms, truth-functional and relevant (in particular, intuitionistic) implication, multiple and complex truth values, and program types. The distinguishing feature of CPL is that it unifies and refines a variety of existing approaches. This feature is the result of our wholistic conception of property-based (modal logics) and model-based (process algebra) formalisms. We illustrate the expressiveness of CPL on representative requirements engineering case studies. Further, we extend (core) CPL (qualitative time) with rational-valued time , i.e., time stamps, timed keys, and potentially drifting local clocks, to tCPL (quantitative time). Our extension is conservative and provides further evidence for Lamport's claim that adding real time to an untimed formalism is really simple. Furthermore, we sketch an extension of (core) CPL with a notion of probabilistic polynomial-time (PP) computation. We illustrate the expressiveness of this extended logic (ppCPL) on tentative formalisation case studies of fundamental and applied concepts. Fundamental concepts: (1) one-way function, (2) hard-core predicate, (3) computational indistinguishability, (4) ( n -party) interactive proof, and (5) ( n -prover) zero-knowledge. Applied concepts: (1) security of encryption schemes, (2) unforgeability of signature schemes, (3) attacks on encryption schemes, (4) attacks on signature schemes, and (5) breaks of signature schemes. In the light of logic, adding PP to a formalism for cryptographic protocols is perhaps also simple and can be achieved with an Ockham's razor extension of an existing core logic, namely CPL.
Nathaniel E. Baughman, Marc Liberatore, Brian Neil Levine
We explore exploits possible for cheating in real-time, multiplayer games for both client-server and serverless architectures. We offer the first formalization of cheating in online games and propose an initial set of strong solutions. We propose a protocol that has provable anti-cheating guarantees, is provably safe and live, but suffers a performance penalty. We then develop an extended version of this protocol, called asynchronous synchronization, which avoids the penalty, is serverless, offers provable anti-cheating guarantees, is robust in the presence of packet loss, and provides for significantly increased communication performance. This technique is applicable to common game features as well as clustering and cell-based techniques for massively multiplayer games. Specifically, we provide a zero-knowledge proof protocol so that players are within a specific range of each other, and otherwise have no notion of their distance. Our performance claims are backed by analysis using a simulation based on real game traces
Based on the assumption that only weak-trusted relation exists among the participants,designated confirmer signatures in weak-trusted relation has the following security requirements: Process separated between signature construction and verification,zero-knowledge proofs,un-transformability and fakery prevention.A confirmer signature algorithm based on RSA public-key cryptography is proposed,and verification processes are presented,described both in non-formal method and in Camenisch-Michels model.The security of this algorithm is proved to be equivalent to RSA cryptographic functions.
A Publicly Verifiable Secret Sharing(PVSS) scheme is a verifiable secret sharing scheme with the property that the validity of the shares distributed by the dealer can be verified by any party,hence verification is not limited to the respective participants receiving the shares.So there are more application fields than a verifiable secret sharing.A non-interactive and information-theoretic PVSS scheme based on public cryptography and the zero-knowledge proof of knowledge were presented.It is very simple to implement,extend and renew this scheme,which especially fits the publicly verifiable secret sharing for general access structure.
This paper describes an idea of securing mobile agents. The presented method protects all the code, the data and the execution state. The proposal is based on a zero-knowledge proof system and a secure secret sharing scheme. The paper also gives security analysis of the new method.
In this paper, we describe a new zero-knowledge proof procotol based on the discrete logarithm and higherorder non-linear variable coefficient differential transformation. By using the high order differential state sequence, the casuality of the system and the capability of resistance to identity deception and differential attacks is enhanced. By introduction of differential transformation method and input-output table into zero-knowledge proof protocol, a new research field for cryptography of zero-knowledge proof identity authentication is thus opened up.
Zero-knowledge proof has been one of the key technologies to be applied in identity authentication in the fields of information security.To avoid the use of the graph isomorphism problem in the known zero-knowledge proof systems,an efficient computational zero-knowledge proof of knowledge whose security relies on the NP-Completeness of the independent set problem is presented here.The proposed logarithm is constructed from a bit commitment scheme based on the hardness of the discrete logarithm problem,which guarantees the fulfillment of soundness,completeness and computational zero-knowledge properties.The system and its logarithm parameter choice were analyzed from two aspects of computational complexity and communication complexity.It was proved theoretically that the system is feasible and effective.
Biometric Identification and Security
Access Control and Trust
Advanced Steganography and Watermarking Techniques
Access control in decentralised collaborative systems present huge challenges especially where many autonomous entities including organizations, humans, software agents from different security domains seek to access and share resources in a secure and controlled way. Automated trust negotiation (ATN) is one approach that has been proposed for trust discovery and realisation, which enables entities viz. strangers to access resources across autonomous boundaries through iterative exchange of credentials. Various negotiation strategies have been proposed to protect credential disclosure during trust negotiations. However in some domains such as e-health, not all entities are willing to negotiate credentials or disclose access policies directly to strangers regardless of negotiation strategies and instead prefer to negotiate and disclose sensitive information only to strangers within what we refer to as a circle of trust. In this paper, we introduce a formal model to describe how locally trusted intermediary parties can provide multiple negotiation and delegations hops to protect credentials and access policies. We propose a dynamic trust negotiations (DTN) model that not only protects sensitive information from disclosure but also reduces semantic issues that exist with credentials in decentralized systems. This work is currently being explored and implemented within the e-health domain: specifically in the MRC-funded Virtual Organisation for Trials of Epidemiological Studies (VOTES) project