Bitcoin’s ‘last resort’ quantum-safe solution just got 79% cheaper: StarkWare

The estimated computational cost to prepare a quantum-resistant Bitcoin transaction has fallen below $67 after a week of optimization, down from the roughly $320 spent on the first such mainnet transaction in August, according to StarkWare. 

The results came after participants in the Quantum-Safe Bitcoin Optimization Challenge found ways to push down the GPU computation needed to build a quantum-safe Bitcoin transaction. 

The reduction could make the experimental defense (which doesn’t require changes to the network’s consensus rules) against future quantum attacks more practical for Bitcoin holders. However, the latest optimizations have only been demonstrated in benchmark tests. 

“A construction that costs a few hundred dollars per transaction is a demo. One that costs $67 is closer to something a holder with a large unexposed balance might reach for in an emergency,” StarkWare wrote in its Sept. 23 update. The dashboard now shows the estimated cost has dropped to $66.

Quantum-Safe Bitcoin an “emergency” solution

StarkWare researcher Avihu Levy published the Quantum-Safe Bitcoin (QSB) design in April, outlining a way to add hash-based protection against quantum attacks without changing Bitcoin’s consensus rules. At the time, he described it as a “last resort measure” due to costs, complexity and limited applicability, while continuing to advocate for protocol-level changes.