On Sat, 2 Jul 1994, Eli Brandt wrote:
It boils down to this: I can't remember as many bits as the TLAs can crack by brute force.
Have you *tried* to memorize these long passphrases? I pick ones that are substantially too complex for me to memorize in one trial. So I write the candidate passphrase on paper until I have a grasp on it, then burn the paper, scatter the ashes (yes, literally), and begin to use the passphrase. My experience is that once I've successfully remembered a phrase two or three times, I will not forget it. ...
I have actually tried memorizing truly random passwords of 8 characters or longer (generated with a paranoid program similar to PGP 2.6's excellent technique). I've found that if I review it enough, that I find patterns and mnemonic clues in such passwords that help me to remember them. I don't imagine too many people will go through that effort, so I still think that a longer pass phrase that sort of "makes sense" is better for a PGP key. Still, I do use the truly random passwords on publicly accessible Unix systems like CSN, since that makes dictionary attacks improbable.