Finding Hash Collisions

Hash functions play an important role in information technology. They are incorporated in many security protocols and security-critical applications and ensure essential security properties for the overall systems. To verify their current status of security, hash functions are regularly exposed to new attacks from the scientific community. Almost all of these attacks are executed on standard PCs. However, the relevance of such attacks is limited: real attackers are not confined to the use of standard PCs. Instead they could develop specialized hardware that executes attacks much faster or cost-efficient. In this book we examine which alternative hardware technologies are suited for developing specialized architectures for the execution of attacks on hash functions. As a proof-of-concept, we develop a very cost-efficient microprocessor with a specialized instruction set and corresponding assembler software. Based on this, we implement a full hardware unit to search for collisions in hash functions. We show that executing attacks on our architecture is, given a fixed amount of money, multiple times faster than on standard PCs.