We construct two new multiparty digital signature schemes that allow multiple signers to sequentially produce a compact, fixed-length signature. First, we introduce a new primiti...
Alexandra Boldyreva, Craig Gentry, Adam O'Neill, D...
At TCC 2005, Backes and Cachin proposed a new and very strong notion of security for public key steganography: secrecy against adaptive chosen covertext attack (SS-CCA); and posed ...
Abstract. Whereas encryption schemes withstanding passive chosenplaintext attacks (CPA) can be constructed based on a variety of computational assumptions, only a few assumptions a...
Ronald Cramer, Goichiro Hanaoka, Dennis Hofheinz, ...
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...
In this paper we define and provide a general construction for a class of policies we call dynamic policies. In most existing systems, policies are implemented and enforced by ch...
Prasad Naldurg, Roy H. Campbell, M. Dennis Mickuna...