Cryptanalysis and improvement of an ID-based ad-hoc anonymous identification scheme at CT-RSA 05

An ad-hoc anonymous identification scheme is a new multi-user cryptographic primitive that allows participants from a user population to form ad hoc groups, and then prove membership anonymously in such groups. Recently, Nguyen \cite{Lan05} proposed an ID-based ad-hoc anonymous identification scheme from bilinear pairings. However, in this paper, we propose an attack on Nguyen\u27s ID-based ad-hoc anonymous identification scheme. We show that any one can impersonate a valid group member to perform the anonymous identification protocol successfully. Furthermore, we propose a solution to improve this scheme against our attack

Critical Perspectives on Provable Security: Fifteen Years of Another Look Papers

We give an overview of our critiques of “proofs” of security and a guide to our papers on the subject that have appeared over the past decade and a half. We also provide numerous additional examples and a few updates and errata

Performances of Cryptographic Accumulators

International audienceCryptographic accumulators are space/time efficient data structures used to verify if a value belongs to a set. They have found many applications in networking and distributed systems since their in- troduction by Benaloh and de Mare in 1993. Despite this popularity, there is currently no performance evaluation of the different existing de- signs. Symmetric and asymmetric accumulators are used likewise without any particular argument to support either of the design. We aim to es- tablish the speed of each design and their application's domains in terms of their size and the size of the values

Security of Ubiquitous Computing Systems

The chapters in this open access book arise out of the EU Cost Action project Cryptacus, the objective of which was to improve and adapt existent cryptanalysis methodologies and tools to the ubiquitous computing framework. The cryptanalysis implemented lies along four axes: cryptographic models, cryptanalysis of building blocks, hardware and software security engineering, and security assessment of real-world systems. The authors are top-class researchers in security and cryptography, and the contributions are of value to researchers and practitioners in these domains. This book is open access under a CC BY license