Bean Counter

Tricky challenge. The description is trying to throw me off from “My counter can go both upwards and downwards to throw off cryptanalysts”, which is not the case. The given code for encryption given is trying to simulate AES-CTR mode by doing AES-ECB block-by-block with the given IV. However, in the code of increment(), the method for changing the IV, there is a very sneaky bug: 1 2 3 4 5 6 7 def increment(self): if self....

December 7, 2022 · 2 min · qvinhprolol