Bitcoin Thunderbolt Network: Reconstructing the off-chain Interaction Paradigm

Bitcoin, as a decentralized and immutable cryptocurrency, faces issues of long transaction confirmation times and high fees in everyday payment scenarios. The original design intention of the Bitcoin main chain was not to handle high-frequency small payments, which creates a contradiction with people's real demand for convenient use of Bitcoin.

To solve this problem, the Lightning Network has emerged. It establishes payment channels off-chain to achieve high-frequency bookkeeping, ultimately synchronizing only the fund status at the time the channel is closed to the blockchain. This model is similar to settling accounts in one go after accumulating expenses among friends. However, the Lightning Network has also exposed many issues in practical applications: high thresholds for channel construction, complex routing, and security risks. These structural defects have made it difficult for its application to break through bottlenecks, with the total locked amount in the entire network being only about 100 million USD, which is negligible compared to the trillion-level market capitalization of Bitcoin.

In this context, the Thunderbolt protocol was born. It is a soft fork upgrade based on the Bitcoin main chain, directly enhancing Bitcoin's scalability, transaction performance, and programmability at the protocol level. Thunderbolt leverages UTXO Bundling technology to increase transaction speed by approximately 10 times; by reintroducing the OP_CAT opcode, it achieves smart contract functionality; and it also introduces the Goldinals asset issuance standard and the BitMM on-chain automated market maker system.

The core mechanism of Thunderbolt includes:

1. Flexible and adjustable multi-signature: Split and encrypt the signatures to achieve non-interactive transfers.

2. Asynchronous fault-tolerant committee ledger: A service group composed of multiple nodes is responsible for bookkeeping, enhancing system robustness.

3. Atomic Swap Finalization: Ensure off-chain reconstruction and on-chain redemption are completed in one go through three-step atomic swaps.

Compared to existing Lightning Network solutions, Thunderbolt has significant advantages in security and theoretical completeness. Its protocol design can be proven to be secure, and malicious users cannot profit unilaterally under any circumstances. However, Thunderbolt also faces challenges such as complex deployment, limited compatibility with the main chain, and lack of ecological support.

The emergence of Thunderbolt may have a significant impact on BTCFi. It may be integrated as a Rollup, becoming the DeFi engine on the Bitcoin side; it could also form an independent standard ecosystem, developing its own network, nodes, and application system; of course, if simpler and more efficient solutions emerge in the future, Thunderbolt could also be replaced.

The greatest significance of Thunderbolt lies in enabling Bitcoin assets to possess "off-chain contract composability" for the first time. By introducing the two features of UTXO Bundling and OP_CAT, it brings native programmability and higher transaction throughput to the Bitcoin network. This makes it possible to unify the Bitcoin ecological protocol and accommodate various assets. Although Thunderbolt is still in the theoretical research stage, it undoubtedly opens up new pathways for the future development of Bitcoin.