Cryptographic hash functions are widely used in practice for a variety of applications, including password hashing, digital signatures, bitcoin and more. The fact that hash functions are public allows attackers to perform pre-computation before attacking the system. However, the traditional security bounds for the above applications either do not apply at all, or do not give accurate security bounds when pre-computation is allowed.
In this talk, we focus on non-uniform attackers, which can obtain arbitrary (but bounded-length) pre-computed advice about the hash function before attacking the system. We introduce optimal and generic tools for analyzing the non-uniform security of hash-function-based applications. Furthermore, we give simple compilers that transform any secure scheme (in the traditional sense) into one that is secure against non-uniform attackers.
2018-03-16 15:30 ~ 16:30
Siyao Guo, Northeastern University
Room 602, School of Information Management & Engineering, Shanghai University of Finance & Economics