Quantum-Safe Bitcoin Transaction Successfully Executed on Mainnet
The first quantum-safe Bitcoin transaction has been successfully executed on the mainnet without requiring any changes to the base protocol. This milestone was achieved through a method called Quantum-Safe Bitcoin (QSB), which adds an extra layer of security using hash functions rather than elliptic curve cryptography.
According to StarkWare, the confirming transaction was routed through MARA Slipstream, a service run by Marathon Digital that allows for direct submission of non-standard transactions. The QSB method uses signature grinding, where the sender searches for a spending transaction whose hash is a validly formatted signature, allowing Bitcoin to accept it.
The security of the resulting output rests on the difficulty of reversing a hash, not on the secrecy of a private key. Shor's algorithm does not break hash functions in the same way, making QSB a viable option for protecting against quantum attacks.
However, the current cost of using QSB is several hundred dollars per transaction, which limits its accessibility to wealthy users. This has raised concerns about security inequality among crypto participants and centralization risks due to reliance on a single miner service.