Public-Key Steganography with Active Attacks

A complexity-theoretic model for public-key steganography with active attacks is introduced. The notion of steganographic security against adaptive chosen-covertext attacks (SS-CCA) and a relaxation called steganographic security against publicly-detectable replayable adaptive chosencovertext attacks (SS-PDR-CCA) are formalized. These notions are closely related to CCA-security and PDR-CCA-security for public-key cryptosystems. In particular, it is shown that any SS-(PDR)CCA stegosystem is a (PDR-)CCA-secure public-key cryptosystem and that an SS-PDR-CCA stegosystem can be realized from any PDR-CCA-secure public-key cryptosystem with pseudorandom ciphertexts.

• Type: Conference
• Year: 2005
• Where: TCC
• Authors: Michael Backes, Christian Cachin
• Keywords: Cryptography, PDR-)CCA-secure Public-key Cryptosystem, Public-key Cryptosystem, Steganographic Security, TCC 2005