UK government planning a database of every phone call and email by the public -- in the name of fighting terror....

[mawilson 2,133]

With large values of n, yes. With small, maybe not. That's my only point. Even if there are multiple meaningful cleartexts in a scenario with 2^8 possible values, it's still a small enough number where each can be investigated/pursued independently.

Well, basically, the only thing you know about the message is its length. Does that help you decipher it? Not really.

P.S. I sorta see your point - but even with length=5, you end up with a list of all 5-letter words. How useful is that? Not useful at all.

Edited May 21, 2008 by mawilson

[w¡n9Nµ7 §£@¥€r 123]

With large values of n, yes. With small, maybe not. That's my only point. Even if there are multiple meaningful cleartexts in a scenario with 2^8 possible values, it's still a small enough number where each can be investigated/pursued independently.

Well, basically, the only thing you know about the message is its length. Does that help you decipher it? Not really.

Well, you know two things. You know the length. And you know the set of possible cleartexts. Depending on the size of the set, you can go through it easily or not at all.

[mawilson 2,133]

With large values of n, yes. With small, maybe not. That's my only point. Even if there are multiple meaningful cleartexts in a scenario with 2^8 possible values, it's still a small enough number where each can be investigated/pursued independently.

Well, basically, the only thing you know about the message is its length. Does that help you decipher it? Not really.

Well, you know two things. You know the length. And you know the set of possible cleartexts. Depending on the size of the set, you can go through it easily or not at all.

Fine, they should always pad their messages with spaces to a full Meg, then apply the pad and send it.