New Exploration of Bitcoin Smart Contracts: Comparison of OP_NET and Arch Solutions

Recently, the two solutions OP_NET and Arch for implementing smart contracts on the Bitcoin mainnet have sparked widespread discussion. Although the name OP_NET is similar to OP_CAT, the two are fundamentally different.

OP_CAT is a Bitcoin opcode that functions to concatenate strings. Since its removal by Satoshi Nakamoto in 2010, there has been a call to restore it. Currently, the related proposal BIP-347 is still in the early stages. Although BCH and BSV have re-enabled OP_CAT, actual use cases remain somewhat abstract. Restoring OP_CAT may just be the first step in unlocking the potential of Bitcoin smart contracts.

In contrast, OP_NET is more similar to protocols like RUNE and BRC-20. Its framework consists of two main parts: the Bitcoin mainnet as the layer for transaction initiation and final confirmation, and the execution layer composed of OP_VM and OP_NET nodes.

The workflow of OP_NET is as follows: users initiate transactions containing the "BSI" identifier from the Bitcoin mainnet, the execution layer detects and processes these transactions, updates the contract status, and finally feeds the results back to the application. This process is somewhat similar to the off-chain indexer model.

One characteristic of OP_NET is that it "burns" a certain amount of Bitcoin. The transaction fees include network fees and OP_NET fees, which are further divided into execution fees and priority fees. When OP_NET fees exceed 0.0025 Bitcoin, 330 Satoshi will be "burned", and the remaining portion will serve as a reward for node operators.

It is worth noting that the team behind OP_NET is related to MotoSwap, and the project also includes the OP_20 and OP_721 standards, indicating a tendency for "new protocols, new assets."

On the other hand, the Arch project has secured $7 million in seed round funding, with participation from several well-known investment institutions. Arch will issue its own coin to be used as Gas fees and validator staking.

Arch is positioned as "Bitcoin Layer 1.5", which is a smart contracts layer built on the Bitcoin mainnet. Its workflow involves initiating transactions on the Bitcoin mainnet, Arch nodes processing verification, and leader nodes responsible for block transactions and submitting confirmation results back to the Bitcoin mainnet.

In terms of technical details, Arch provides more information about network stability and the execution layer. For example, by adopting the "FROST + ROAST" signing scheme, network security can be guaranteed as long as 51% of the network members cooperate honestly.

Although Arch has its own token as gas fees, users can still pay with Bitcoin, and the backend will automatically convert it, simplifying the user experience.

Overall, OP_NET and Arch have similarities in their technical implementation, both using the Bitcoin mainnet as the transaction initiation and confirmation layer, while serving as the execution layer. However, their positioning is different: OP_NET is more like a protocol, while Arch is a "Bitcoin 1.5 layer" solution.

Both solutions face the challenge of longer confirmation times on the Bitcoin mainnet, which may affect the efficiency of dApps. However, these explorations are still of significant importance for the development of the Bitcoin ecosystem.

For investors and users, Arch plans to conduct a token generation event (TGE) in the first quarter of next year, and may launch related testing activities or dApps based on Arch. OP_NET currently does not have clear participation opportunities, and its development may depend on the overall enthusiasm of the ecosystem.