Messing around on cyberchef I stumbled on some weird DES behavior. Encrypting a message with a key of “password” could also be decrypted with the key “passwosd” example. After some further investigation the following keys were also able to decrypt the message correctly:
- passwosd
- passwose
- password
- passwore
- pasrwosd
- pasrwose
- pasrword
- pasrwore
- parswosd
- parswose
- parsword
- parswore
- parrwosd
- parrwose
- parrword
- parrwore
The same behavior was observed with different plaintexts, IVs, and operating modes. Additionally, when different IVs were used substantial portions of the message were still decrypted successfully example.
I know that DES is old and outdated for a number of reasons, but does anyone know why it's possible for multiple keys to decrypt a message?
