Specification of the Identity Mixer Cryptographic Library (Revised version 2.3.0)*

As we are transforming into a digital society, it is vital that we protect our data in all of our transactions. This requires that transactions are securely authenticated, and that we protect privacy by not revealing more about ourselves than necessary. Anonymous credentials promise to address both of these seemingly opposing requirements at the same time. Anonymous credentials are essentially a privacy-enhancing public-key infrastructure which require standardization to be widely used. Anonymous credential systems are far more complex than ordinary signature schemes since they provide more functionality in order to address all of the requirements of a public-key infrastructure with privacy protection. Unfortunately, the descriptions of these features are spread over many research papers and it is often not clear how they could all be securely integrated into a single system. This paper describes the Identity Mixer anonymous credential system that integrates cryptographic techniques from many sources to build an anonymous credential system with a rich feature set. The aim of this paper is to stimulate standardization efforts towards a privacy-enhancing public-key infrastructure.

*The first version of this Research Report was entitled "Cryptographic Protocols of the Identity Mixer Library"
**Correspondence should be addressed to Jan Camenisch, jca@zurich.ibm.com
Revised version 2.3.0 of RZ Report: April 29, 2010

By: Security Team**, Computer Science Department, IBM Research - Zurich, 8803 Rüschlikon, Switzerland

Published in: RZ3730 in 2009

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rz3730_revised.pdf

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