Daniel J. Bernstein and Tanja Lange
There is a flaw in the standard security definitions used in the literature on provable concrete security. The definitions are frequently conjectured to assign a security level of 2^128 to AES, the NIST P-256 elliptic curve, DSA-3072, RSA-3072, and various higher-level protocols, but they actually assign a far lower security level to each of these primitives and protocols. This flaw undermines security evaluations and comparisons throughout the literature.
We have written a paper  analyzing the magnitude of the flaw in detail, showing how it varies across cryptosystems and across cost metrics, and discussing several strategies for fixing the definitions. We also wrote  to show how small DLPs can be solved more efficiently (with non-free precomputation) if there are many of them.
This talk will present some highlights.