Math

The other day I was working on a proof to show that there is a polynomial transformation from SUBSET-SUM-ZERO to SUBSET-SUM-ONE where the two problems are decision problems and are defined as follows: SUBSET-SUM-ZERO: Given a list of integers, if there exists a non-empty subset of those integers that sum to $0$, return YES. Otherwise return FALSE. SUBSET-SUM-ONE: Given a list of integers, if there exists a non-empty subset of those integers that sum to $1$, return YES....

Many people are familiar with the PS3 exploit discovered in 2010 by the fail0Overflow group. This exploit was the result of Sony reusing the value $k$ in their implementation of the Elliptic Curve Digital Signature Algorithm. By reusing the value for $k$, the private key can be directly calculated (the details of which can be seen here) But the answer to “how do you detect $k$ being reused” isn’t as prevalent....