The recently proposed universally composable (UC) security framework for analyzing security of cryptographic protocols provides very strong security guarantees. In particular, a p...
Cryptographic computations are often carried out on insecure devices for which the threat of key exposure represents a serious concern. Forward security allows one to mitigate the...
A classical construction of stream ciphers is to combine several LFSRs and a highly non-linear Boolean function f. Their security is usually analysed in terms of correlation attack...
ded abstract of this paper appears in Advances in Cryptology – EUROCRYPT ’03, Lecture Notes in Computer Science Vol. 2656, E. Biham ed., Springer-Verlag, 2003. This is the full...
We introduce captcha, an automated test that humans can pass, but current computer programs can’t pass: any program that has high success over a captcha can be used to solve an u...
Luis von Ahn, Manuel Blum, Nicholas J. Hopper, Joh...