Hash-Based Signatures for Bitcoin's Post-Quantum Future

The recent paper introduced a new variant of the Dilithium algorithm, named DilithiumRK (Randomized Keys), which incorporates BIP-32-like functionality. This enhancement is achieved by eliminating a public key compression step found in the original Dilithium algorithm, which was responsible for the loss of homomorphic properties. This modification necessitates several changes to the algorithm, including the introduction of a new public network parameter that is crucial for seed and key generation processes. However, this adaptation from the standard FIP 204 protocol comes with its set of trade-offs. Notably, the size of signatures increases due to the inclusion of an error hint. Furthermore, the process of signing becomes significantly slower, with a reported 2.7 times increase in duration, and verification times also suffer, becoming 1.75 times slower.

Additionally, the email mentions a BIP-32-like scheme developed for Falcon signatures. While the sender admits to having limited familiarity with this particular scheme, they highlight a significant increase in the size of signatures — from approximately 666 bytes for standard Falcon signatures to about 24KB under the new scheme. This information underscores the ongoing efforts and challenges in the development of cryptographic protocols that balance functionality with performance and security considerations.

Relevant sources include a paper on the proposed DilithiumRK algorithm (link 1) and another on the BIP-32-like scheme for Falcon signatures (link 2). These contributions to the field of cryptography reflect the dynamic nature of research aimed at enhancing the security and functionality of digital signature schemes within the context of cryptocurrency technologies, such as those used in Bitcoin development.