Protecting privacy in e‐cash schemes by securing hidden identity approaches against statistical attacks

Abstract

Purpose

To enhance security and privacy of e‐cash systems that apply revocable anonymity by presenting a statistical attack that reveals the hidden ID and suitable protection means against this kind of attack.

Design/methodology/approach

The feasibility of a statistical attack that reveals the ID of user of e‐cash schemes with revocable anonymity is shown. To avoid such attacks the application of modulo operations while constructing e‐cash coins is proposed. Measurement results are used to back up the suitability of this approach.

Findings

Revocable anonymity systems can successfully be attacked. Applying modulo operations can prevent such attacks.

Practical implications

The recommendations given in this paper should be applied whenever an e‐cash scheme or similar system with revocable anonymity is designed. Otherwise the promised feature may be compromised very easily.

Originality/value

The paper identifies a formerly unknown attack against systems with revocable identities, and presents a mathematical solution to protect such systems against the attack presented.

Citation

Piotrowski, K., Langendörfer, P., Maye, O. and Dyka, Z. (2006), "Protecting privacy in e‐cash schemes by securing hidden identity approaches against statistical attacks", Internet Research, Vol. 16 No. 2, pp. 159-169. https://doi.org/10.1108/10662240610656492