New Post Quantum Bitcoin Proposal using WInternitz + Lamport auth chains

The project aims to utilize the Lamport + Winternitz method, which is recognized for its efficiency and minimal quantum signature size, thus being highly suitable for integration through Taproot by adjusting parameters to enhance compactness and practicality.

The core of this system lies in a Lamport authorization chain that secures the use of Winternitz one-time signatures, starting from a seed phrase and proceeding through a hash chain sequence. This setup ensures that each Winternitz public key can authenticate only one transaction, thereby maintaining robust security protocols. Further details on this innovative approach are available in a detailed security essay and a Bitcoin proposal outline hosted on block_opuslux.ar.io.

However, there have been concerns regarding potential challenges such as the scalability of nullifier sets, privacy implications due to address reuse upon spending, and limitations in multi-user transactions or fee adjustments when using this method exclusively. Opus Lux has clarified these issues, noting optimization strategies to bound live state growth and maintain function without compromising the existing UTXO set. A significant upgrade proposed involves decoupling key derivation from UTXO outpoints to ensure privacy, aligning with traditional Bitcoin operations.

In response to feedback, further revisions are planned to refine the protocol's design to be more Bitcoin-native, prioritizing privacy and simplicity. These improvements aim to address the complexities of integrating post-quantum cryptographic methods into Bitcoin's existing framework while preserving user flexibility and network functionality.