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0 pointstptacek11y ago0 comments

What actual MAC is that?

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3 comments · 1 top-level

owenmarshall11y ago· 2 in thread

What actual MAC is what?

Sorry, I'm a bit confused by the question :)

It's been awhile since I looked at anything in Telegram and I forget what MAC they use. That diagram makes it look like instead of a MAC, they're using a simple digest of the message --- which is not a MAC.

owenmarshall11y ago

Heh. I just looked again and had misread their specs: I thought the shared secret went into their SHA-1. You are correct, they just take a digest.

So I can make any message look OK just by hashing the plaintext. Heh. Wonder what that KDF looks like...

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