Quantum-safe bitcoin now possible without a soft fork, but costs $200 a pop

A recent breakthrough in quantum-safe bitcoin transactions has been introduced by a StarkWare researcher, Avihu Levy. This method, known as Quantum Safe Bitcoin (QSB), aims to secure bitcoin transactions against potential quantum attacks without requiring any changes to the existing Bitcoin protocol. The innovative scheme utilizes hash-based proofs instead of traditional signature-based security assumptions, making it resistant to quantum computing threats.

In the traditional system, digital signatures act as a form of authorization for transactions, similar to a handwritten signature on a cheque. However, the current ECDSA signatures used in Bitcoin could be vulnerable to attacks from future quantum computers. QSB addresses this vulnerability by implementing a hash-based design that creates a unique mathematical digest of data, making it extremely difficult to forge or reverse, even for powerful quantum computers.

One of the key advantages of QSB is that it operates within Bitcoin’s existing consensus rules for legacy transactions, eliminating the need for any protocol upgrades or changes. This sets it apart from other proposals like BIP-360, which require significant governance processes and implementation timelines. QSB builds upon an earlier concept known as Binohash, which added an additional layer of computational work to enhance transaction security.

However, the implementation of QSB comes at a cost. Generating a valid transaction using QSB requires significant computational power, estimated to cost between $75 and $200 using commodity cloud GPUs. This is a stark contrast to the current average transaction fee of around 33 cents on the Bitcoin network. Additionally, QSB transactions may need to be sent directly to miners for processing, bypassing the traditional blockchain pathway.

While QSB offers a temporary solution for quantum-safe transactions, it is considered a “last resort measure” due to its high cost and complexity. Long-term solutions like BIP-360, which aim to introduce quantum-resistant signature schemes through a soft fork, remain the preferred option but may take years to activate. The activation timeline for BIP-360 is uncertain, with low odds of implementation this year.

Overall, QSB provides a unique approach to addressing quantum threats in the Bitcoin network using existing rules and protocols. It offers users a way to safeguard their transactions against potential quantum attacks, albeit at a higher cost. As the industry continues to evolve, innovations like QSB will play a crucial role in ensuring the security and integrity of the Bitcoin network.