A Post Quantum Migration Proposal

In the discussion about post-quantum (PQ) signature integration within the Bitcoin network, several innovative proposals are considered to ensure a smooth transition. The conversation revolves around the idea of adapting the current consensus to accommodate PQ signatures by imposing specific requirements such as formatting constraints or size limitations for DER signatures. For instance, it suggests that signatures could be required to occupy less than a certain number of bytes, with the possibility of integrating relative timelocks to favor smaller signatures through lower timelock requirements.

The dialogue also touches upon the challenges of migrating to PQ signatures due to the exposure of some public keys while others remain hidden behind hashed outputs like P2PKH (Pay to Public Key Hash). It is proposed that in scenarios where the public key is unknown to the network, committing to a proof at the time of transaction spending could be a viable solution. This approach hinges on the premise that not all details are discernible at every network level, thereby necessitating a commitment to some form of proof to facilitate transactions under these circumstances.

An intriguing aspect of the discussion centers on employing temporal mechanisms as a stopgap measure to achieve consensus on PQ signature adoption. The concept of using timelocks on OP_CHECKSIG operations as a deliberation period is suggested, implying that if consensus on migration paths remains elusive, extending the timelock could serve as a temporary solution. This proposal underscores a strategic use of time in decision-making processes, suggesting that repeated extensions could eventually lead to a consensus or, alternatively, pave the way for new methodologies based on Proof of Work or other consensus mechanisms to determine asset ownership.

Furthermore, the discourse acknowledges the potential for deadlock in reaching a consensus on how to migrate funds securely in a post-quantum context. It hints at an ultimate reliance on the broader community's hash power to make determinations about asset control in the absence of a clear agreement. This perspective highlights a pragmatic approach to governance and decision-making within the Bitcoin ecosystem, recognizing the utility of hash rate as a decisive factor in the interim period of technological transition.