Fair Non-repudiation Protocol Research Articles

Assume-guarantee synthesis for digital contract signing

Abstract We study the automatic synthesis of fair non-repudiation protocols, a class of fair exchange protocols, used for digital contract signing. First, we show how to specify the objectives of the participating agents and the trusted third party as path formulas in linear temporal logic and prove that the satisfaction of these objectives imply fairness ; a property required of fair exchange protocols. We then show that weak ( co-operative ) co-synthesis and classical ( strictly competitive ) co-synthesis fail, whereas assume-guarantee synthesis ( AGS ) succeeds. We demonstrate the success of AGS as follows: (a) any solution of AGS is attack-free ; no subset of participants can violate the objectives of the other participants; (b) the Asokan–Shoup–Waidner certified mail protocol that has known vulnerabilities is not a solution of AGS; (c) the Kremer–Markowitch non-repudiation protocol is a solution of AGS; and (d) AGS presents a new and symmetric fair non-repudiation protocol that is attack-free. To our knowledge this is the first application of synthesis to fair non-repudiation protocols, and our results show how synthesis can both automatically discover vulnerabilities in protocols and generate correct protocols. The solution to AGS can be computed efficiently as the secure equilibrium solution of three-player graph games.

A Fair Non-repudiation Protocol without TTP on Conic Curve over Ring n Z

A Fair Non-repudiation Protocol without TTP on Conic Curve over Ring n Z

Fair non-repudiation for web services transactions

To safeguard the interests of transacting parties, non-repudiation mechanisms need to assure fairness and timeliness. The non-repudiation service currently implemented usually does not consider the requirement of fairness and the fair non-repudiation protocols to date can not be suitably applied in real environment due to its complex interaction. This paper discusses the transaction-oriented non-repudiation requirement for Web services transaction, analyzes the constraints of the traditional model for the available fair non-repudiation protocols and designs a new Online-TTP fair non-repudiation protocol. The new protocol provides a fair non-repudiation solution to secure Web services transactions and can be embedded into a single Web service call. The protocol adopts evidence chained to decreasing the overhead of evidence verification and management and alleviates the overhead of certificate revocation checking and time-stamp generation for signatures. The protocol has strong fairness, timeliness, efficiency and practicability.

An Extended Payment Model for M-Commerce with Fair Non-Repudiation Protocols

Non-repudiation in e-commerce has recently gained a lot of interest but its successor brother, non-repudiation in m- commerce, is still at the start. In this paper, we propose an extension of existing mobile payment models to introduce an extended mobile payment service (EMPS) model, which is based on assumptions about the cooperation between mobile network operators and financial institutions to deal with different payment amounts ranging from micro to macro payment. The novel model focuses on enhancement of non-repudiation problem. Fair non-repudiation protocols are developed for not only payment phase but also other phases in a typical m- commerce transaction, including price negotiation and content delivery. Joint signatures method is used in protocols to overcome the limitations in mobile handheld device capability and to reduce the trust dependence totally on the payment service. As with the proposed non-repudiation protocols, EMPS plays the role of a semi-trusted third party and is an indispensable factor for creating the fairness property. Non- repudiation analyses of these protocols are also conducted besides some guidelines for ensuring non-repudiation in m- commerce.

Design and verification of a non-repudiation protocol based on receiver-side smart card

All the existing non-repudiation protocols ensuring strong fairness have to assume that the communication channel between trusted third party (TTP) and each player is resilient at least. Where only unreliable channel can be guaranteed, all these protocols become impractical. In this study, based on smart card on the receiver side, the authors design a fair non-repudiation protocol that needs no assumptions on the communication channel. The smart card takes over the role of an online TTP server. Without a dedicated TTP server, this protocol is ideal for some ad hoc scenarios where no infrastructure is available. This protocol can also be easily modified to support fair exchange of time-sensitive data. Compared with other traditional security protocols, automatic formal verification of fair non-repudiation protocols is much harder to achieve. The authors use meta-reasoning method to prove that the fair exchange property of this protocol can be reduced to three secrecy properties that fall into the scope of today's most automatic verification tools and therefore can be easily verified. The authors also use a recently proposed automatic method to verify the non-repudiation properties and fairness property of our protocol.

A New Fair Non-repudiation Protocol for Secure Negotiation and Contract Signing

A New Fair Non-repudiation Protocol for Secure Negotiation and Contract Signing

Smart card-based agents for fair non-repudiation

Non-repudiation protocols are of great importance for electronic interactions. Different protocols have been proposed in this field, progressively relaxing the requirements on the computing power of both parties, and on the load and involvement of a trusted third party (TTP). Besides, there is a need to provide mobile users with a protocol adequate for ad hoc scenarios, where only unreliable channels can be guaranteed, and where the CA may not be reachable. In this paper we propose a new version of the fair non-repudiation protocol proposed by Gurgens et al. in [Sigrid Gurgens, Carsten Rudolph, Holger Vogt, On the security of fair non-repudiation protocols, in: Colin Boyd, Wenbo Mao (Eds.), ISC, Lecture Notes in Computer Science, vol. 2851, Springer, 2003, pp. 193-207]. We show unfair scenarios that can appear if one party controls the communication among the TTP and the other party. We introduce notary agents, which play the TTP role, and run our fair non-repudiation protocol. Notary agents execute inside the smart card, and sign the protocol messages with the user's private key on his behalf. Our approach enables the protocol to run on unreliable channels, disconnected from the CA.

Formal Analysis of Timeliness in Non-Repudiation Protocols

While SVO logic has been widely used in the analysis of non-repudiation protocols for its simplicity, its lack of the ability in time description makes it helpless in the analysis of timeliness, which is one of the most important properties of non-repudiation protocols. SVO logic is extended by adding a simple time expression and analysis method into it. Then a widely discussed fair non-repudiation proposed by Zhou and Gollmann in 1996 and one of its improvements are analyzed with the newly extended logic. The result shows that Zhou-Gollmann's fair non-repudiation protocol does not provide timeliness while its improvement does. Therefore, the new logic is able to analyze timeliness of non-repudiation protocols. In addition, the new logic can be used to analyze other time-related properties of cryptographic protocols.

Security analysis of efficient (Un-) fair non-repudiation protocols

Abstract An approach to protocol analysis using asynchronous product automata (APA) and the simple homomorphism verification tool (SHVT) is demonstrated on several variants of the well known Zhou–Gollmann fair non-repudiation protocol and on two more recent optimistic fair non-repudiation protocols. Attacks on all these protocols are presented and an improved version of the Zhou–Gollmann protocol is proposed.

On the security of fair non-repudiation protocols

We analyzed two non-repudiation protocols and found some new attacks on the fairness and termination property of these protocols. Our attacks are enabled by several inherent design weaknesses, which also apply to other non-repudiation protocols. To prevent these attacks, we propose generic countermeasures that considerably strengthen the design and implementation of non-repudiation protocols. The application of these countermeasures is finally shown by our construction of a new fair non-repudiation protocol.

Fair multi-party non-repudiation protocols

In this paper we introduce the concept of multi-party non-repudiation protocols. We define the aims of multi-party non-repudiation protocols, compare them to multi-party fair exchange and show some fundamental differences. We present two protocols, the first one using an online trusted third party and the second one using an offline trusted third party. We also show how to modify each of these protocols in order to provide confidentiality. The definitions and the resulting protocols are more general than the only comparable work, a multi-party certified e-mail protocol.

An intensive survey of fair non-repudiation protocols

With the phenomenal growth of the Internet and open networks in general, security services, such as non-repudiation, become crucial to many applications. Non-repudiation services must ensure that when Alice sends some information to Bob over a network, neither Alice nor Bob can deny having participated in a part or the whole of this communication. Therefore a fair non-repudiation protocol has to generate non-repudiation of origin evidences intended to Bob, and non-repudiation of receipt evidences destined to Alice. In this paper, we clearly define the properties a fair non-repudiation protocol must respect, and give a survey of the most important non-repudiation protocols without and with trusted third party (TTP). For the later ones we discuss the evolution of the TTP's involvement and, between others, describe the most recent protocol using a transparent TTP. We also discuss some ad-hoc problems related to the management of non-repudiation evidences.

Achieving Fair Nonrepudiation in Electronic Transactions

The fast development of computer networks has facilitated electronic commerce. Meanwhile, some security problems may arise in such a new business environment. Nonrepudiation services, in which evidence is generated, collected, and maintained to enable dispute resolution, protect the transacting parties against any false denial that a particular event or action has taken place. In addition, fairness is a desirable requirement such that neither party can gain an advantage by quitting prematurely or otherwise misbehaving during a transaction. In this article, I investigate the techniques and protocols that use a (trusted) third party to achieve fair nonrepudiation in electronic transactions, and I discuss some applications of these fair nonrepudiation protocols.

On the efficient implementation of fair non-repudiation

Due to the explosive growth of electronic businesses carried on the Internet, non-repudiation services turn out to be increasingly important. Non-repudiation services protect the transacting parties against any false denial that a particular event or action has taken place, in which evidence will be generated, collected and maintained to enable the settlement of disputes. Several fair non-repudiation protocols have been proposed, which support non-repudiation of origin and non-repudiation of receipt while neither the originator nor the recipient can gain an advantage by quitting prematurely or otherwise misbehaving during a transaction. However, a critical issue on how to maintain the validity of non-repudiation evidence efficiently during and after a transaction was not considered. This paper uses the idea of evidence chaining to address such a problem.