Non-uniform Security: Limits on the Power of Pre-Computation (Siyao Guo)


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