Outlets covering StarkWare's first quantum-safe Bitcoin mainnet transaction give different figures for how much the off-chain computation cost.
What all sources agree on
- StarkWare executed what it describes as the first quantum-safe Bitcoin transaction confirmed on mainnet.
- The method, Quantum-Safe Bitcoin (QSB), was designed by Avihu Levy, StarkWare's general manager of applications, who published the research in April 2026.
- StarkWare engineer Tomer Giladi helped bring the method to a working mainnet transaction.
- The transaction required no change to Bitcoin's consensus rules, soft fork, or new opcode.
- QSB uses signature grinding to produce a valid Bitcoin signature relying on hash pre-image resistance rather than elliptic-curve cryptography, making it resistant to attacks using Shor's algorithm.
- Because the transaction used a nonstandard format, it could not travel through the ordinary mempool and was sent directly to a miner via MARA's Slipstream service.
- QSB cannot protect an address whose public key has already been exposed on-chain.
- StarkWare CEO Eli Ben-Sasson and Avihu Levy both said a Bitcoin soft fork remains the preferred long-term solution to quantum risk.
Where the reports disagree
1Cost of the off-chain computation required per QSB transaction
StarkWare says the approach currently costs several hundred dollars in off-chain computation
The QSP currently requires $75 to $150 in off-chain GPU computation per transaction
In Levy’s studies, the cost of off-chain GPU computation necessary to produce a transaction is about $75 to $200, while the abstract of the study says that the amount involved would be a few hundred dollars.
StarkWare put the cost of the completed mainnet spend at several hundred dollars and hours of computation.
The transaction takes between $75 and $150 in cloud GPU compute, so the computational costs are way too high for QSB to be sustainable.
StarkWare says the approach currently costs several hundred dollars in computation. Supplementary reporting by Cointelegraph said StarkWare described the process as taking hours of computation and estimated a completed-transaction cost of roughly $150 to $200.
What would settle it: StarkWare's own published cost figures for the completed mainnet transaction, or Avihu Levy's underlying research paper.
What to make of it
Treat the existence of the mainnet transaction, its method, and its no-soft-fork requirement as established across all sources; do not rely on any single dollar figure for the computation cost, since reports range from about $75 up to several hundred dollars and were not reconciled.
Treat the existence of the mainnet transaction, its method, and its no-soft-fork requirement as established across all sources; do not rely on any single dollar figure for the computation cost, since reports range from about $75 up to several hundred dollars and were not reconciled.