- Round: 30 (2023/01)
- Category: Crypto
- Points: 200
- Solves: 2
There are a lot of DSA challenges this month, so why not end this round with yet another (EC)DSA challenge?
You can get 3 linear equations modulo q by eliminating d from ECDSA equations, and you can get another 3 linear equations modulo p using the LCG relations. Build a lattice with these 6 equations being columns then use LLL to find k and recover d.