post-quantum: solution ideas to "tripwire"game-theory issues + a certificate-based rescue protocol

The exploration of solutions to mitigate the risks associated with game-theory difficulties in blockchain technology, specifically related to "tripwire" issues, is vital as quantum computing threats loom. One proposed method involves utilizing a New UTXO Model Space (NUMS) point spend as a standalone proof of work equivalent. This approach suggests that by hardcoding a NUMS point into a coinbase output, it could serve as an intrinsic proof of work, thus potentially increasing the chain work of the included block significantly (e.g., 20 times the last period's difficulty). This would shift the consensus mechanism amongst network nodes to a new chain ordering that does not rely solely on having the majority of hash power, thereby diluting the power of potentially malicious majorities.

Another alternative focuses on group signatures from a set of post-quantum upgraded coins, incorporating a novel Merkle tree of these signatures within the commitment structure of blocks. This method assigns a "weight" to the block based on the amount of post-quantum coins signed, which could exceed a predefined threshold to enhance the block’s proof of work order and activate the "tripwire." This system is designed to be resistant to the capabilities of a cryptographic quantum computer (CRQC), as forging these signatures would require significant coin ownership beforehand. However, it also introduces the risk of social manipulation, where a majority could meet the threshold to influence the "tripwire" activation unfairly.

On a more technical note, addressing the issue of EC coin owners who might become vulnerable due to CRQCs involves leveraging the Bitcoin blockchain itself as a timestamped publication medium for certificates of discreet log knowledge. These certificates would provide a historical proof of ownership, crucial when traditional cryptographic methods are compromised by quantum capabilities. The certificate format is simple and includes a signature committing to all fields, allowing a zero-knowledge proof to verify the owner knew the discreet log at a specific time block. This preemptive measure enables coin transfers aligned with post-quantum policies even after "tripwire" activation, although it acknowledges the uncertainty around the timing and impact of CRQC emergence.

These discussions underscore the complexity and urgency of developing robust, quantum-resistant blockchain mechanisms to safeguard against potential adversarial actions in a future where quantum computing is feasible. Each solution offers a strategic but distinct approach to enhancing blockchain security in anticipation of new technological advancements.