Oracle Attacks and Covert Channels

In this paper, well-known attacks named oracle attacks are formulated within a realistic network communication model where they reveal to use suitable covert channels, we name oracle channels. By exploiting information-theoretic notions, we show how to modify detection/authentication watermarking algorithms in order to counteract oracle attacks. We present three proposals, one based on randomization, another one based on time delay and a third one based on both randomization and delay.