harvest now, decrypt later: the attack that's already running.

an attacker doesn't need a quantum computer today. they need a tape recorder and patience. record the traffic, store the ciphertext, and wait for the machine that cracks it.

that's harvest-now-decrypt-later, and it's not hypothetical. nation-states are already doing it against traffic they expect to matter in a decade. your chain's elliptic-curve signatures are exactly the kind of thing that gets harvested.

a lattice signature has no known quantum shortcut. when the machine arrives, the harvested ciphertext is still gibberish. that's the whole reason Lattice exists.