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[Ethernull]

Brute Forcing and Frequency Analysis?

[Ciaran_H]

Vignere ciphers are immune to frequency analysis if done well - that's the point.

I wouldn't consider frequency analysis on standard substitution ciphers as "brute forcing", unless of course there's something in-game to tell us what it is. But even then, I wouldn't consider it as such because that's really the only realy way to start decoding one of those.

"Brute forcing" is the wrong phrase for this anyway. Brute forcing is trying all possible combinations until one happens to work, which bypasses the method of actually trying to work it out.

I don't know about Playfair ciphers so I can't comment on them.

[Ethernull]

Cool, thanks for the quick answer!

For what its worth, given enough cypher text, you can crack a Vigenere up to a key length of 20 letters or so using a frequency analysis on repeating patterns in the cypher text, without knowing the key length.
(I'd be hap to crack a vigenere and explain how I did it as an example if you want)

Playfair uses paired letter substitution with a key and pairing fomula, fairly strong but not as good as vigenere.

[aliendial]

Actually we've never had a problem with people crashing through a cipher any way they want. If it can be broken in a nonstandard way, the PMs have learned a lesson. All of this done on your own computer or with other tools you have access to.

When we speak of brute forcing (the bad kind) we are referring to massive resource-sucking attacks on something like a password box on a game site with a dictionary bot (or whatever) where you are actually costing the PMs bucks and perhaps crashing their site by submitting every 2 seconds all day every day looking for the answer. That's the no-no.