Oracle channels

Abstract

The paper is structured into three main parts. In the first part, we focus on information leakage through new covert channels, we term oracle channels, which occur in case oracle attacks are performed on watermarked digital media or multimedia. In the second part, we show how to counteract oracle channels without resorting to protection tools that are quite demanding for communication networks. In the third part, we follow the information-theoretic approach to show that the countermeasures proposed in the second part do reduce the secret information leakage that flows through oracle channels, without sensibly compromising the detector reliability in case no oracle attack is performed. © 2008 Springer-Verlag Berlin Heidelberg.