Malicious Hashing: Eve's Variant of SHA-1 [chapter]

Ange Albertini, Jean-Philippe Aumasson, Maria Eichlseder, Florian Mendel, Martin Schläffer
2014 Lecture Notes in Computer Science  
We present collisions for a version of SHA-1 with modified constants, where the colliding payloads are valid binary files. Examples are given of colliding executables, archives, and images. Our malicious SHA-1 instances have round constants that differ from the original ones in only 40 bits (on average). Modified versions of cryptographic standards are typically used on closed systems (e.g., in pay-TV, media and gaming platforms) and aim to differentiate cryptographic components across
more » ... or services. Our proof-of-concept thus demonstrates the exploitability of custom SHA-1 versions for malicious purposes, such as the injection of user surveillance features. To encourage further research on such malicious hash functions, we propose definitions of malicious hash functions and of associated security notions.
doi:10.1007/978-3-319-13051-4_1 fatcat:qpzc4drqw5fkxbz25qnobr62fi