Giving teeth to expected EC disabling: P2XX(-T)(-ML)

The discussion outlines various methods for implementing a tripwire mechanism within blockchain consensus rules to ensure all nodes simultaneously recognize proofs, specifically those related to the Elliptic Curve Discrete Logarithm Problem (ECDLP). The importance of integrating such proofs directly into the blockchain is emphasized to avoid discrepancies that might lead to forks. Different approaches are considered, including using a transaction output known to be Nothing-Up-My-Sleeve (NUMS), which is favored for its simplicity and lack of additional infrastructure requirements. Alternatively, publishing the discrete logarithm problem (DLP) solution in a transaction or a coinbase with a specific marker is proposed, though these methods raise concerns about testing and message relay reliability.

Further elaboration on the proposed mechanisms explains the potential use of an advanced proof form combining signature, message, and tweak to demonstrate key-path spends by potentially malicious parties, although the relevance of this approach is questioned given the unlikely scenario of attackers targeting specific outputs first. Concerns regarding miners' control over event ordering and their possible manipulation of trigger events are also discussed. A delay between trigger activation and enforcement is suggested as a mitigation strategy, alongside modified parameters for existing Bitcoin Improvement Proposals (BIPs).

In addition to technical proposals, the philosophical stance on not catering to self-crafted hybrid schemes is affirmed, arguing instead for simpler solutions like separate script leaf versions devoid of ECC opcodes. The notion of the tripwire not being a security feature per se but rather a means of setting user expectations around output types is also explored. The complexities associated with testing these mechanisms, including the support for fake tripwires and the need for robust DoS protection measures, are highlighted. Lastly, the inherent challenges in modifying or unfreezing such mechanisms without a hardfork, which would not be accepted by nodes operating under the original tripwire logic, are recognized, indicating the irreversible nature of these decisions once implemented.