Algorithm substitution attacks on symmetric encryption: a survey

Abstract

In 2014, Bellare, Paterson, and Rogaway suggested formalizing Algorithm Substitution Attacks (ASAs), a new type of attack against symmetric encryption methods. These attacks replace the conventional encryption algorithm with a subverted one, enabling the attacker, known as Big Brother, to decrypt messages without the user's collaboration. The formal definitions of these attacks highlight the user's capacity to identify the subversion (i.e., the replacement of regular encryption with a malicious one) and the Big Brother's capacity to gather data about encrypted messages. In recent years, the cryptographic community has developed several definitions, attacks, and possible defenses to increase its awareness of this potential issue.In this paper, we will explore the algorithm-substitution attack concepts and assaults available in the literature, comparing them with a critical eye.