Vote for Pedro

First, the modulus is big (2048 bits) and the public exponent e is small (3), hence we may use a small number and the arithmetic operation under the modulo N is the same as in $\mathcal Z$ Pedro is not exactly careful with the padding, indeed: 1 2 3 4 5 6 7 8 vote = int(your_input['vote'], 16) verified_vote = long_to_bytes(pow(vote, ALICE_E, ALICE_N)) # remove padding vote = verified_vote.split(b'\00')[-1] if vote == b'VOTE FOR PEDRO': return {"flag": FLAG} Anything in the verified_vote variable before the null byte is discarded, hence a message of the form <SOME RANDOM STUFF>\x00VOTE FOR PEDRO is still valid....