[Bitcoin Researchers Focus on Adopting 'Hash-Based Signatures' for Quantum-Resistant Upgrades] According to DL News, in a revised paper published on December 5, Blockstream researchers Mikhail Kudinov and Jonas Nick explored various methods to upgrade the Bitcoin blockchain to make it quantum-resistant. The two researchers believe that hash-based signatures are a highly attractive post-quantum solution because their security relies solely on hash function assumptions, which are similar to the foundational design of Bitcoin. Kudinov introduced their research findings in an email sent to the Bitcoin developers' mailing list, stating: 'These schemes have undergone extensive cryptanalysis during the post-quantum standardization process by the National Institute of Standards and Technology (NIST), which has increased confidence in their robustness.' Hash-based signatures rely on hash functions, a mathematical algorithm considered quantum-resistant. Unlike the public key encryption technology used by Bitcoin, quantum algorithms find it difficult to break hash functions. Hash functions can ensure the security of applications like digital signatures by simply increasing the output size to counter brute-force searches by quantum computers, making the search space too large. However, how developers will implement hash-based signatures is still under discussion. Decisions need to be made on issues such as keeping verification costs low, whether to standardize multiple implementations of hash-based signatures, and whether the entire network's historical records are required to verify transactions.