Avihu Levy: StarkWare Confirms Quantum-Safe Bitcoin Transaction on Mainnet

StarkWare Proves Bitcoin Ownership Can Be Shielded From Quantum Threats

StarkWare has shown that Bitcoin holders can move coins into storage a quantum computer cannot open. The company announced on August 26 that the first quantum-safe Bitcoin transaction was mined on mainnet in block 964199. The transaction used the QSB method developed by Avihu Levy and required no changes to Bitcoin consensus rules.

The method relies on hash-based locks combined with off-chain signature grinding known as Binohash. Engineer Tomer Giladi turned Levy’s April 2026 research into a working mainnet transaction. Because the transaction is nonstandard it could not enter the ordinary mempool and was submitted directly through MARA Slipstream. The spend moved a 10,000-satoshi output and paid a 5,179-satoshi fee.

CEO Eli Ben-Sasson described the work as an after-hours passion project that demonstrates Bitcoin holdings can be protected before any future soft fork. The transaction offers reassurance that coins whose public keys remain unpublished can be moved with quantum-resistant protection. StarkWare noted that the approach does not make the entire Bitcoin network quantum-safe and cannot protect addresses whose public keys have already been revealed.

Ownership and Utility in Practice

Bitcoin ownership today rests on the ability to spend coins without exposing them to future quantum attacks. The QSB transaction shows a practical path for holders who keep public keys hidden. The off-chain computation cost several hundred dollars, yet the result proves the method works on live Bitcoin without altering protocol rules. This utility matters because roughly 30 percent of Bitcoin supply sits in addresses that could become exposed if quantum computing advances.

The transaction stands apart from unrelated roadmaps discussed elsewhere in the industry. It focuses solely on a working mainnet spend rather than long-term protocol upgrades. Holders now have a concrete example that coins can be secured with hash-based conditions before any soft fork occurs.

Market Context on August 30

On CoinGecko at approximately 9:31 a.m. ET the majors showed modest gains. Bitcoin traded at $78,714, up 1.4 percent. Ethereum sat at $2,466.39, up 1.3 percent. XRP moved to $1.40, up 0.9 percent. Solana reached $106.34, up 2.5 percent. Dogecoin traded at $0.085385, up 0.6 percent. These candles reflect steady price action while the quantum-safe development adds a new layer of utility discussion around Bitcoin ownership.

Limits That Keep the Method Opt-In

QSB remains an opt-in tool rather than a network-wide fix. It cannot help addresses that have already published public keys. The nonstandard format means every future use will likely require direct miner submission. StarkWare continues to favor a soft fork for broader protection while this transaction serves as an immediate proof of concept.

The successful mainnet run in block 964199 gives holders a concrete reference point. Ownership can be exercised today with quantum-resistant safeguards even if full protocol changes arrive later. This story centers on that demonstrated utility rather than speculation about future price moves.