Ensuring Data Security and Individual Privacy in Health Care Systems

Ph.DDOCTOR OF PHILOSOPH

A new hardware-assisted PIR with O(n) shuffle cost

Ministry of Education, Singapore under its Academic Research Funding Tier

A study of content authentication in proxy-enabled multimedia delivery systems: Model, techniques, and applications

Singapore Management Universit

Privacy-Preserving Credentials Upon Trusted Computing Augmented Servers

Abstract. Credentials are an indispensable means for service access control in electronic commerce. However, regular credentials such as X.509 certificates and SPKI/SDSI certificates do not address user pri-vacy at all, while anonymous credentials that protect user privacy are complex and have compatibility problems with existing PKIs. In this pa-per we propose privacy-preserving credentials, a concept between regular credentials and anonymous credentials. The privacy-preserving creden-tials enjoy the advantageous features of both regular credentials and anonymous credentials, and strike a balance between user anonymity and system complexity. We achieve this by employing computer servers equipped with TPMs (Trusted Platform Modules). We present a detailed construction for ElGamal encryption credentials. We also present XML-based specification for the privacy-preserving credentials.

Fortifying Password Authentication in Integrated Healthcare Delivery Systems

Singapore Management Universit

CCA-secure unidirectional proxy re-encryption in the adaptive corruption model without random oracles

Proxy re-encryption (PRE), introduced by Blaze, Bleumer and Strauss in Eurocrypt\u2798, allows a semi-trusted proxy to convert a ciphertext originally intended for Alice into an encryption of the same message intended for Bob. PRE has recently drawn great interest, and many interesting PRE schemes have been proposed. However, up to now, it is still an important question to come up with a chosen-ciphertext secure unidirectional PRE in the adaptive corruption model. To address this problem, we propose a new unidirectional PRE scheme, and prove its chosen-ciphertext security in the adaptive corruption model without random oracles. Compared with the best known unidirectional PRE scheme proposed by Libert and Vergnaud in PKC\u2708, our schemes enjoys the advantages of both higher efficiency and stronger security