BITCOIN’S FIRST QUANTUM-PROOF SIGNATURE PLAN HITS PAPER — 13X SMALLER THAN THE GOVERNMENT’S VERSIONS — THE FINE PRINT SAYS “SECURITY PROOF: TODO”

Blockstream researchers Jonas Nick and Mikhail Kudinov published the first concrete post-quantum signature proposal written for Bitcoin. SHRINCS is hash-based — it leans on SHA-256, the same assumption Bitcoin’s mining already rests on — supports normal seed-phrase recovery, and has run on the Liquid sidechain since March. The size math is the sales pitch: about 13 times smaller than the government-standardized post-quantum schemes, which keeps Bitcoin near 3 transactions per second instead of dropping it below one. The Technologist read: this is exactly what a serious protocol answer looks like, and exactly why nobody should call it finished. The document itself says the formal security proof is a TODO. The compact signing path is stateful — the device must remember which one-time keys it has used, reusing state can compromise those keys, and restoring a seed to a new device falls back to a much bigger signature. There is no assigned BIP number yet; Taproot took 22 months with nearly no opposition, and a realistic activation window runs to 2028 at the earliest. The protocol moves at the speed of review, not the speed of headlines. That is a feature.