26
Feb
2012

CODEGATE 2012 – Misc-2

Challenge Description

Alice wants to send a message to Bob in secure way. Alice encrypted a plaintext PA = ¡°IMISSYOU¡± = 0x494D495353594F55 by using DES and obtained ciphertext CA = 0xFA26ED1833264435.
Alice sent the ciphertext CA and the secret key to Bob. The secret key was encrypted by converting each of its letters to a pair of digits giving its position in the typewriter keyboard.

{Read More}