the size of a post-quantum key, explained.

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by the lattice team · 02 september 2026

a classical secp256k1 public key is 33 bytes. a ML-KEM-1024 public key is around 1.5 kilobytes. people see that and panic.

but the size isn't waste — it's the proof of the guarantee. every byte of a lattice key is doing cryptographic work that a quantum computer can't undo. you're trading kilobytes for a problem with no quantum shortcut.

a few kilobytes per handshake, handled by the sdk, invisible to users. that's a bargain for a chain that outlives the quantum.

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