Oral Messages vs Signed Messages
With unauthenticated (oral) messages, Byzantine agreement needs 3f+1 nodes even under synchrony because a traitor can relay altered claims; with unforgeable digital signatures, synchronous agreement works for any number of faults because tampering with a relayed message is detectable. Signatures change what a liar can get away with, not whether he can lie.
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With unauthenticated (oral) messages, Byzantine agreement needs 3f+1 nodes even under synchrony because a traitor can relay altered claims; with unforgeable digital signatures, synchronous agreement works for any number of faults because tampering with a relayed message is detectable. Signatures change what a liar can get away with, not whether he can lie.
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