Protocols and Systems for Privacy Preserving Protection of Digital Identity

Bhargav-Spantzel, Abhilasha Ph.D., Purdue University, December, 2007. Protocols and Systems for Privacy Preserving Protection of Digital Identity. Major Professor: Elisa Bertino. To support emerging online activities within the digital information infrastructure, such as commerce, healthcare, entertainment and scientific collaboration, it is increasingly important to verify and protect the digital identity of the individuals involved. Identity management systems manage the digital identity life cycle of individuals which includes issuance, usage and revocation of digital identifiers. Identity management systems have improved the management of identity information and user convenience; however they do not provide specific solutions to address protection of identity from threats such as identity theft and privacy violation. One major shortcoming of current approaches is the lack of strong verification techniques for issuance and usage of digital identifiers. In the absence of verification mechanisms, digital identifiers can be misused to commit identity theft. Another shortcoming is the inability of individuals to disclose minimal data while satisfying strong identity verification requirements. The extraneous data collected can potentially be aggregated or used in a manner that would lead to violation of an individual’s privacy. Finally, current identity management systems do not consider biometric and history-based identifiers. Such identifiers are increasingly becoming an integral part of an individual’s identity. Such types of identity data also need to be used with other digital identifiers and protected against misuse. In this thesis we introduce a number of techniques that address the above problems. Our approach is based on the concept of privacy preserving multi-factor identity verification. The technique consists of verifying multiple identifier claims of an individual, without revealing extraneous identity information. A distinguishing feature of our approach is that