Comment Re:This is more of authentication than encryption. (Score 1) 106
Think of it as ROT-n encryption of random data, where n is the key
If you choose the wrong n, you'll still get blob of random data back, just not the correct one.
Now, the tricky part is in making sure the incorrect keys returns data that's hard to distinguish (meaning it can't be done automatically and/or quickly) from the correct plain text, when the plain text ISN'T random looking, but something like passwords, SSN, credit card numbers.