Bitcoin's covenant debate often fixates on what the protocol lacks. Developer Adi Man flipped the script with MCCV, a proof-of-concept vault built using only CheckTemplateVerify (CTV).
His design treats unspent transaction outputs as states in a machine. Since CTV cannot natively create cycles, the implementation unrolls the logic into a massive tree of millions of pre-computed states. This enables about a thousand operations, including reactive security measures like clawing back funds if a hot key is compromised.
"Covenant debates usually focus on what Bitcoin lacks. Adi Man built a proof of concept called MCCV to see how far basic CheckTemplateVerify (CTV) can go."
- Bitcoin Optech
The complexity is significant, a point noted by developer Murch. Adi Man views it as a baseline, suggesting a more expressive opcode like CheckSigFromStack would allow for actual cycles and a smaller state machine.
Separately, developers are mapping a post-quantum future. One proposal secures node-to-node traffic by combining current encryption with modular lattice-based math, avoiding a consensus change. For the Lightning Network, the challenge is more fragmented. A single quantum-resistant solution doesn't exist, requiring separate keys for transport, gossip, and on-chain scripts.
A routing node with 1,000 channels updating every 10 minutes would exhaust a leading post-quantum signature scheme's lifetime limit in about four months. The consensus is to run classical and post-quantum systems in parallel for a long transition.
Finally, work continues on usability for advanced setups. A new proposal from Pyth seeks to standardize the payload for air-gapped signing of complex Miniscript policies via QR codes, solving a critical pain point for multisig users.
