A Formal IT-Security Model for a Weak Fair-Exchange Cooperation with Non-repudiation Proofs

Author

Grimm, Rüdiger

Author_Institution

Inst. of Inf. Syst. Res., Univ. Koblenz-Landau, Koblenz, Germany

fYear

2009

fDate

18-23 June 2009

Firstpage

49

Lastpage

56

Abstract

This article presents a formal IT-security model for the step-by-step exchange of digital items. Following the taxonomy of Asokan the model presented here addresses the security requirements for a so-called ldquoweakrdquo fair exchange. ldquoWeakrdquo refers to the fact, that third parties are used to dissolve disputes. In this model, non-repudiation proofs are used in an external dispute to establish weak fairness. It shows how many unproved steps can be tolerated by one party without loss of fairness. The model is based on the idea of a ldquocontinuous balance of obligations and their proofsrdquo. This idea was proposed 1993 by Grimm, but never since formalized properly.

Keywords

cryptographic protocols; public key cryptography; set theory; digital item; fair exchange protocol; formal IT security model; freedom-of-obligation property; nonrepudiation proof; public-key certification; set theory; step-by-step exchange; weak fair-exchange cooperation; Computer security; Electronic mail; Information security; Information systems; Internet; Law; Legal factors; Protocols; Sections; Taxonomy; IT-security model; fair exchange; non-repudiation; obligation; secure state; transition rule; trust model;

fLanguage

English

Publisher

ieee

Conference_Titel

Emerging Security Information, Systems and Technologies, 2009. SECURWARE '09. Third International Conference on

Conference_Location

Athens, Glyfada

Print_ISBN

978-0-7695-3668-2

Type

conf

DOI

10.1109/SECURWARE.2009.15

Filename

5211042