# Tag Info

There's an easy attack against public keys with $e=3$. Here's how it works; the attacker selects an arbitrary message $M$ that hashes to an odd value $H$ (or, more generally, a $H$ of the form $k8^n$ for odd $k$). Since half of the potential messages hash this way, this is not a severe limitation to the attacker. Then, the attacker looks for a perfect ...