AG 1, AG 2, AG 3, AG 4, AG 5, SWS, RG1, MMCI   Info

Expert Audience

English

60 Minutes

Saarbrücken

Ubiquitous electronic transactions give us efficiency and convenience, but
introduce security and reliability issues and affect user privacy.
Consider for example how much more private information is revealed during
online shopping compared to what leaks in physical transactions that are
paid in cash. Luckily, cryptographic research gives us the tools to
achieve efficient and secure electronic transactions that at the same time
preserve user privacy. Anonymous credentials is one such tool that allows
users to prove possession of credentials while revealing the minimum
amount of information required.
In the first part of this talk, we present "Anonymous Credentials Light":
the first provably secure construction of anonymous credentials that is
based on the DDH assumption and can work in the elliptic group setting
without bilinear pairings. Our construction requires just a few
exponentiations in a prime-order group in which the DDH problem is hard,
which makes it suitable for mobile devices, RFIDs and smartcards.

In the second part of the talk we explain how we can get secure e-cash
with attributes from our construction and we show implementation results
in an NFC enabled smartphone. The efficiency of our scheme is comparable
to Brands e-cash, which is known to be the most efficient e-cash scheme in
the literature but as a recently work of us shows it is impossible to
prove it secure under the currently known techniques.

Brigitta Hansen

0681 93039102

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