BIP-119 (OP_CHECKTEMPLATEVERIFY) (no activation)

The discussion centers around the evolution and implications of implementing covenants in the Bitcoin network, particularly through proposals like OP_CHECKTEMPLATEVERIFY (OP_CTV) and its historical precedents such as OP_CHECKOUTPUTHASHVERIFY and OP_SECURETHEBAG. The original motivation behind OP_CTV, as articulated by Jeremy Rubin, was to introduce covenants into Bitcoin with reduced expressivity, aiming for a gradual integration. This approach has evolved over time, including adjustments to template commitments and sizes to mitigate potential disruptive effects.

The conversation shifts to concerns about combining OP_CTV with other primitives, which some argue represents a regression from the strategy of cautious, progressive enhancement. The specific worry is that such combinations could reintroduce vulnerabilities to costless bribe attacks, exemplified by the concept of TxWithhold, as detailed in a blog post by Gleb Naumenko. These attacks could exploit time-sensitive protocols within Bitcoin's Layer 2 solutions or even impact miner incentives by affecting COINBASE_MATURITY. The original analysis of TxWithhold drew from academic work on Miner Extractable Value (MEV) in Ethereum, adapting it to Bitcoin's unique context to assess risks and similarities.

Critics of expanding Bitcoin script primitives without careful consideration argue that the potential for TxWithhold-style attacks needs to be more thoroughly evaluated. They suggest that possible mitigations for key Bitcoin protocols, such as Lightning Network or mining processes, should be prioritized before introducing new script capabilities that could facilitate such exploits. There's also a speculative note on how future developments, like an OP_CSFS-powered TxWithhold contract, could enable trust-minimized bribes to miners, further complicating the security and reliability of the Bitcoin network.

The underlying concern is that ill-considered enhancements to Bitcoin’s scripting capabilities might pave the way for unforeseen MEVs, potentially destabilizing the miner incentive structure and leading to a gradual decline of the network. This scenario draws parallels with other cryptocurrencies that have experienced issues due to rapid or ill-planned consensus changes. The author expresses a personal stance, highlighting their investment in Bitcoin as a novel asset class but acknowledging the risks associated with these technological uncertainties.