Aligning privacy incentives in P2MR

Antoine raises concerns about the effectiveness of using a P2MR (Pay-to-Migration-Request) approach compared to the P2TRv2 (Pay-to-Taproot-Version2) strategy in the context of Bitcoin's migration strategies in response to potential cryptographic risks posed by CRQC (Cryptographically Relevant Quantum Computing). He argues that although the P2MR strategy might address certain issues, it inadvertently introduces higher transaction costs, which could discourage individual users from opting into this system. Antoine points out that these additional costs do not justify the supposed long-range protection offered by P2MR, emphasizing that systemic migration is crucial and should not be hindered by barriers that discourage user participation.

The discussion also highlights an essential aspect of user behavior and incentives in the Bitcoin ecosystem. Antoine notes that while there is a collective benefit for all users to migrate to a new output type that includes an "escape hatch" to counter potential threats from quantum computing advancements, individual incentives do not align with this collective need. This misalignment suggests that without sufficient individual incentives, expecting widespread voluntary migration is unrealistic. This scenario is supported by data indicating that a significant majority of Bitcoin transactions still utilize single-key spending policies, suggesting a conservative approach to adopting new transaction types among users.

Overall, Antoine advocates for the adoption of P2TRv2 over P2MR, citing lower costs and better alignment with user behaviors and incentives. His analysis underscores the importance of designing cryptographic migration strategies that not only address theoretical risks but also align closely with real-world user behaviors and economic realities, ensuring both practicality and broad adoption within the community.