CTV-only Vault Concept v0.1.0 release

The MCCV v0.1.0, introduced as a new implementation of the More Complicated CTV Vault, utilizes the OP_CHECKTEMPLATEVERIFY for creating an advanced vault system without the need for more complex covenant opcodes. This design allows for functionalities such as deposits, delayed withdrawals, recovery options, velocity control, and multiple vault operations, which are crucial for enhancing security and operational flexibility. The vault operations are scalable with deposit and withdrawal increments predetermined and a relative timelock that scales to provide security during transactions. This setup ensures that funds can be secured or recovered to a more protected recovery key if necessary.

This initial release, described as experimental and recommended for use only on signet or regtest environments, operates with Bitcoin Inquisition v29 and supports various features like generating vaults, managing transactions through a hot wallet, and executing delayed withdrawals. The detailed functioning and protocols can be accessed through the More Complicated CTV Vault GitHub repository and the included user guide and protocol specification documents.

Despite its innovative approach, the MCCV system presents several challenges including complexity, computational demands, and trust issues regarding vault generation. The complexity may deter its use for securing large balances, while the high computational requirements stem from the granularity of transaction increments and the total number of supported operations. Additionally, the necessity for powerful and trustworthy hardware for vault generation poses significant trust challenges. Future improvements may include integration with STARK-based verification systems for enhanced security and feasibility on hardware wallets.

Further, this vault design, though not the first to use OP_CHECKTEMPLATEVERIFY, is unique in its combination with taproot, providing efficiency and expanded functionalities compared to previous designs like Bryan Bishop's Bitcoin Vaults and other simple CTV vault implementations. However, newer opcode developments like OP_VAULT and OP_CHECKCONTRACTVERIFY could potentially supersede this design by simplifying the transaction processes and reducing the need for extensive precomputation.

Feedback is sought on the overall protocol design, user experience, performance, and computational aspects to refine and enhance the MCCV project. The potential future work highlights areas such as watchtower software development, delegated recovery mechanisms, improvements in vault computation caching, CPU optimizations, and general software adaptability to support various CTV-based protocols. These enhancements aim to address user experience issues and optimize performance, making MCCV a more viable and secure option for managing digital assets.