StarkWare Deploys Quantum-Safe Bitcoin Transaction on Mainnet

A team from StarkWare has announced that it has successfully executed a Bitcoin transaction using its Quantum Safe Bitcoin (QSB) design on the mainnet. The transaction, which was mined in block 964,199 on August 26, demonstrates the feasibility of QSB but does not independently verify its quantum resistance claims.

According to StarkWare, the QSB method utilizes Bitcoin's existing legacy scripting rules and requires no soft fork. It uses a hash-based one-time signature and a 'hash-to-signature' puzzle that relies on RIPEMD-160 preimage resistance rather than elliptic curve hardness.

The design estimates that an attacker would need to attempt roughly 2^46 combinations before successfully executing the transaction, making it theoretically resistant to quantum attacks. However, StarkWare emphasizes that QSB does not make Bitcoin quantum-safe and only protects coins after they are moved into a special output. It also does not retrofit resistance onto ordinary ECDSA- or Schnorr-secured holdings.

Avihu Levy, the researcher behind the QSB design, has described it as a last-resort measure due to its complexity and onchain cost, which do not scale to Bitcoin's expected users and throughput. The transaction itself was nonstandard and required a direct path to a miner, with MARA Pool providing the mining service through its Slipstream platform.