New Bitcoin Smart Contract Scheme: Similarities and Differences between OP_NET and Arch

Recently, OP_NET and Arch, two smart contract implementations of the Bitcoin mainnet, have sparked extensive discussion. While OP_NET name is similar to OP_CAT, the two are very different in nature.

OP_CAT is a Bitcoin opcode that is used for string concatenation operations. Its resurrection involves a soft fork of the Bitcoin network, and the proposal is still ongoing. While it has been resurrected on BCH and BSV for many years, there are still limited real-world use cases. The resurrection of OP_CAT could be the first step in unlocking the potential of Bitcoin's smart contracts.

In contrast, OP_NET belong to the protocol category and have nothing to do with Bitcoin opcodes. Its technical framework includes the Bitcoin mainnet as the "behavior initiation layer" and "final confirmation layer", and the "execution layer" consisting of OP_VM and OP_NET nodes. Users initiate transactions through the Bitcoin mainnet, and the execution layer completes contract operations and status updates, and the final results are submitted to the Bitcoin mainnet.

! [A brief analysis of the two latest Bitcoin smart contract implementations: What is the difference between OP_NET and Arch?] ](https://img-cdn.gateio.im/webp-social/moments-59cf3f7b914cee1bd0f1ea692704899e.webp)

A unique feature of OP_NET is its "burn Bitcoin" mechanism. The transaction fees consist of the basic Bitcoin network fees and OP_NET transaction fees, which are further divided into execution fees and priority fees. When OP_NET transaction fees exceed 0.0025 Bitcoin, 330 Satoshis will be "burned", and the remaining portion will serve as a reward for node operators.

Arch is positioned as the "Bitcoin 1.5 layer" and aims to build a smart contract layer based on the Bitcoin mainnet. The workflow consists of users initiating transactions from the Bitcoin mainnet, Arch nodes processing and validating them, and leader nodes that are responsible for establishing Arch network blocks and submitting confirmed transactions back to the Bitcoin mainnet.

! [A brief analysis of the two latest Bitcoin smart contract implementations: What is the difference between OP_NET and Arch?] ](https://img-cdn.gateio.im/webp-social/moments-44a50b57b38116f954ef220dfd1f954b.webp)

Arch uses the "FROST + ROAST" signature scheme, which ensures network stability as long as 51% of network members cooperate honestly. Although Arch has its own token as a network gas fee, users can still use Bitcoin for contract interactions, and the backend will automatically complete the fee conversion.

Although these two projects have similarities in technical implementation, their positioning is completely different. OP_NET is more inclined towards the "new protocol, new asset" model, while Arch is dedicated to becoming a smart contracts extension layer for Bitcoin.

The long block generation time of the Bitcoin mainnet may limit the efficiency of the applications developed by these two schemes. Still, these explorations are significant for the development of the Bitcoin ecosystem.

It is worth noting that Arch plans to conduct a token generation event (TGE) in the first quarter of next year. Those who are interested in this can follow the related testing activities and applications developed on top of Arch. However OP_NET there is no clear token incentive mechanism at present, and its development may be more dependent on the overall heat of the ecosystem.

! [A brief analysis of the two latest Bitcoin smart contract implementations: What is the difference between OP_NET and Arch?] ](https://img-cdn.gateio.im/webp-social/moments-0a96c028a51cf64523f436b60087736d.webp)