StarkWare Signals New Bitcoin Era With Quantum-Resistant Transaction

• StarkWare said researcher Avihu Levy has demonstrated an experimental quantum-resistant Bitcoin transaction on mainnet. The transaction spent a 10,000-satoshi output in block 964,199 without requiring any changes to Bitcoin’s consensus mechanism.
• According to StarkWare, the transaction represents the first example of its kind. MARA Pool mined it after receiving the transaction directly through its Slipstream platform because its nonstandard structure prevented regular Bitcoin nodes from broadcasting it through the public mempool.
• StarkWare spokesperson Nathan Jeffay estimated the computational expense at roughly $150 to $200. The company said the process took several hours, illustrating both the potential of the technology and the significant computing and operational resources currently required to protect an individual Bitcoin output.

How StarkWare’s Quantum-Safe Bitcoin Transaction Works

• Levy’s Quantum-Safe Bitcoin (QSB) framework, proposed in April, combines hash-based one-time signatures with computational searches that bind spending authorization to a particular transaction. The design aims to prevent fraudulent transactions even if future quantum computers become capable of cracking Bitcoin’s elliptic-curve cryptography.
• Google researchers estimated in March that a sufficiently advanced quantum computer could theoretically derive a Bitcoin private key in nine to 12 minutes once its associated public key is exposed. If achieved, that capability could allow an attacker to interfere with transactions during the confirmation period.
• Rather than replacing Bitcoin’s cryptographic system across the network, QSB focuses on securing individual transactions. The approach lets users move coins into specially protected outputs without modifying Bitcoin’s protocol. However, funds connected to public keys that were already exposed would not receive protection until they are moved to a secure output.
• QSB also faces a relay limitation because its transaction format is considered nonstandard under Bitcoin Core’s default policies. Standard nodes will not propagate it before confirmation, meaning users must transmit the transaction directly to a compatible miner through infrastructure such as MARA’s Slipstream.
• StarkWare CEO Eli Ben-Sasson said the system could serve as a safety layer while developers work toward broader protocol-level defenses against quantum attacks. The technology therefore provides a way to improve transaction security without immediately changing Bitcoin’s underlying cryptography.
• Developers are separately exploring BIP-360, a proposed soft fork that would introduce Pay-to-Merkle-Root outputs and remove Taproot’s vulnerable key-path spending. Such a solution would require coordination across the Bitcoin network before it could be activated.
• Unlike a network-wide upgrade, QSB works within Bitcoin’s existing consensus framework. StarkWare’s mainnet demonstration shows that quantum-resistant spending is possible today, although scaling the approach would require overcoming its current computational and operational limitations.