A transaction method capable of defending against quantum attacks without a Bitcoin soft fork (protocol change) has been introduced. The QSB transaction method, disclosed in a paper by Avihu Levy, Chief Product Officer (CPO) of StarkWare, adopts a structure that complements existing security vulnerabilities and upgrades the existing structure that allows limited transaction lookups in Bitcoin scripts without consensus changes. Furthermore, it provides about 118 bits of preimage resistance even in a Shor's algorithm environment, making it require immense computational power for quantum computers to reverse-trace original data from hash values.