A transaction using the Quantum-Safe Bitcoin (QSB) method has been identified on the Bitcoin main network. StarkWare stated that this was the first time that the programme had been validated on the main web site and that the Bitcoin Consensus Rules had not been amended and that no soft fork had been required.

This is more like a demonstration of technical feasibility. It shows that the existing bitcoin rules are acceptable for such trading structures, but does not mean that the bitcoin network is already fully resistant to quantum attacks.

The rule of consensus is finished.

Traditional bitcoin transactions rely on elliptical curve signatures. Theoretically, if there are sufficiently strong faulty quantum computers in the future, the assailant may use the Shor algorithm to push the private key from the public key.

QSB attempts to shift the safety base from the elliptical curve to the Hash function. According to StarkWare and the researcher Avihu Levy, this method uses the Hashi commitment and specific signature structures to complete the transaction validation under the existing ECDSA certification framework and therefore does not require new codes or nodal upgrades.

Higher generation costs

However, such transactions are not suitable for daily use. Each time a QSB transaction is generated, a large number of calculations are made under the chain to find the transaction parameters that meet the conditions.

According to the study, the calculation cost of GPU for a single QSB expenditure is in the range of US$ 75 to US$ 150, with a partial reduction to US$ 200. These costs do not include the cost of miners on the Bitcoin chain and are recalculated for each transaction.

In addition, QSB transactions are not consistent with the Bitcoin conventional trunking strategy and are usually not disseminated through open memory pools and need to be submitted directly to miners willing to pack. The first main network deal was delivered to the miners via MARA's Slipstream service.

Still unable to cover all bitcoin scenes

The transaction was confirmed only as proof that the current Bitcoin consensus accepted the QSB structure and did not indicate that all addresses, wallets or existing funds were protected against quantum.

As currently designed, QSB is used primarily for the traditional pre-SegWit script output, which for the time being does not directly protect the Taproot output and does not cover lightning network channels. More crucially, funds are transferred to QSB for export through an ordinary transaction before such Hashi protection is obtained.

This means that if the transfer of the pre-public key has been revealed and the quantum attacker has the capacity at that time, the funds may still be attacked before confirmation. Addresses that have been spent before, and therefore made public, are not directly protected by QSB.

The protocol level is still under study.

The researchers described QSB as a “last resort” rather than a large-scale alternative to ordinary bitcoin transactions. Its computational costs, the size of the script and the dependence on the miners ' network all limit its practical application.

Developers are also currently discussing longer-term agreement-level upgrades, such as BIP-360. The proposal seeks to reduce the exposure of bitcoin to long-term quantum attacks through new output designs. Unlike QSB, this type of programme would need to drive changes in the Bitcoin agreement to land.

Next, outside attention will focus on independent review of the QSB code, more master network testing and the development of a more extended back-quant signature programme. At this stage, the transaction is more like a back-up routing, rather than a bitcoin antiquantified signal.