At the Quantum Bitcoin Summit held in San Francisco, experts engaged in a comprehensive and pragmatic discussion on the current state of quantum computing and its potential implications for Bitcoin. The dialogue encompassed ongoing research into various quantum computing architectures, including neutral atoms, trapped ions, superconducting circuits, and photonics. A central challenge identified is the error correction in quantum bits, or qubits, which are highly susceptible to disturbances caused by environmental noise. Presently, maintaining a single logical qubit requires thousands of physical qubits, and scaling such systems to larger, practical sizes remains an unresolved and significant hurdle.
A primary quantum threat to Bitcoin arises from Shor’s algorithm, capable of breaking elliptic curve cryptography that underpins Bitcoin’s security. Addresses that have already revealed their public keys are particularly vulnerable to so-called “long-range attacks,” while those that have not yet disclosed their public keys face risks of “short-range attacks.” It is estimated that approximately 2 million Bitcoins—around 10% of the total supply—are held in addresses vulnerable to long-range attacks. Some experts advocated for the proactive “burning” or deactivation of these at-risk coins should quantum computing reach sufficient power, aiming to mitigate adverse market impacts. As a more balanced alternative, proposals like “Ourglass” were introduced, which seek to limit coin transfers to reduce potential losses without drastic measures.
The summit also examined two principal families of quantum-resistant cryptographic approaches: lattice-based and hash-based schemes. While hash-based cryptography is considered more secure against quantum attacks, it generates larger signature sizes, which may impair blockchain performance. In terms of facilitating secure coin transfers, two methods are under consideration: commit-reveal and zero-knowledge proof schemes. These approaches would enable users to migrate their holdings safely to new quantum-resistant addresses.
Although the threat posed by quantum computing is real, it has yet to manifest as an immediate practical concern. The consensus among attendees emphasized the importance of discontinuing the use of vulnerable addresses and preparing proactively for potential risks. However, there is no need for alarm or premature resource expenditure at this stage. Instead, the community should focus on implementing existing security measures and closely monitoring advancements in quantum computing, adjusting safeguards accordingly as the technology evolves.
Source: bitcoinmagazine
