We deal with the problem of a center sending a secret message to
a group of users such that some subset of the users is considered
revoked and should not be able to obtain the content of the
message. We concentrate on the stateless receiver case, where
the users do ... more >>>

We revisit the question, originally posed by Yao (1982), of whether encryption security may be characterized using computational information. Yao provided an affirmative answer, using a compression-based notion of computational information to give a characterization equivalent to the standard computational notion of semantic security. We give two other equivalent characterizations. ... more >>>