Category: Cryptography Points: 50 Description:

John was messing with RSA again… he encrypted our flag! I have a strong feeling he had no idea what he was doing however, can you get the flag for us? flag.txt


The file we’re provided lists N, E, and C. The thing that stands out the most is that E is only 0x01. Low values of E are frowned upon, but this one takes it to a new level.


In RSA, when e is 0x01, we can simply convert the hex value we’re given for the ciphertext (c) to ascii and get the flag.