Ian Bicking: the old part of his blog

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Remember that (A XOR C) XOR (B XOR C) is A XOR B, so yes, even a little bit of key reuse is bad.

Why aren't you just using HMAC? You probably already have a library for it...

I notice that I've acquired the habit of twitching violently when anyone says something like "homebrew encryption." I wonder where I picked that up.
Comment on Homebrew encryption
by Karl