Potential projects on BTC’s second layer that have not yet been launched

Most of the second-layer projects that have been launched are sidechain architectures, which use various technical solutions to achieve cross-chain asset security and chain security. Most of the following projects have special solutions, so they are basically still under development. Stark announced his entry into the BTC ecosystem yesterday, making this ecosystem more lively! But it seems that many projects depend on whether OP-CAT can pass.

In addition to these second layers, there are actually many protocols related to the BTC ecosystem (staking; DA, etc.). Due to space constraints, we will talk about it next time.

Botanix @BotanixLabs should be a Western second layer that many people pay attention to. Now the test network is in progress, and I know that many projects are ready to build on it. BTC assets are protected by the decentralized multi-signature network Spiderchain. Botanix uses the Bitcoin block hash value as the source, randomly selects nodes to participate in PoS block generation, and finally confirms that the block header is engraved in the BTC block. All L2 assets on BTC are protected by the multi-signature network Spiderchain. Nodes randomly form multi-signature groups to control the BTC in the multi-signature address. The cost of doing evil is high because the BTC pledged can be fined. Testnet address: https://botanixlabs.xyz/en/testnet

Citrea @citrea_xyz ZK-Rollup, dedicated to exploring and researching BitVM implementation. The Citrea network processes transactions in zkVM and generates zk proofs, which are engraved into BTC blocks. Optimistic verification is implemented on the BTC mainnet through BitVM to ensure that Citrea's settlement and data availability are handled by the Bitcoin mainnet. The project will soon open a public testnet, which should be the second layer that is most closely related to BitVM.

Fractal Bitcoin is Unisat's expansion solution. There is relatively little information available, and it has the following characteristics.

Virtualized Bitcoin Core: Encapsulates Bitcoin Core into a deployable and runnable software package, allowing multiple instances to run independently and recursively anchor on the Bitcoin mainnet.

Recursive expansion: Through a hierarchical structure, each layer is implemented using Bitcoin, maintaining consistent fractal characteristics and achieving unlimited computing processing power.

Multi-layer system: Without introducing other blockchain structures, the native engineering structure of Bitcoin is used to expand the system to ensure the robustness and scalability of the network.

Summary of recent Q&A content:

Security: Fractal can resist 51% attacks and ensure network stability through joint mining and dynamic difficulty adjustment algorithm.

Parallel chain: Fractal runs in parallel with the Bitcoin main chain, is compatible with all main chain protocols, and can be settled on the main network through inscriptions.

Native expansion: Fractal does not introduce additional structures and is a native Bitcoin expansion solution.

Innovation: The virtualization strategy is innovative in Bitcoin expansion and different from traditional expansion methods.

Implementation method: By customizing the Bitcoin core, a simplified BCSP is formed to achieve flexible customization and deployment.

UTXO Stack RGB++ expansion solution. RGB++ issues assets on the BTC main network and has a binding relationship with Bitcoin UTXO. Users can choose to "jump" RGB++ assets to the Nervos network for use. The jumped BTC transaction will output a specific UTXO on the main network, trigger related shadow transactions in the Nervos network, and the RGB++ asset information will be written into the Nervos UTXO. The unlocking condition is a specific BTC UTXO. Users can enjoy smart contract capabilities, lower fees, and higher performance in Nervos, and can also jump assets back to the BTC main network through isomorphic binding. Based on the above isomorphic binding ideas, Nervos also released the UTXO Stack application chain architecture, which is similar to Ethereum's OP Stack, and is developing its own lightning network. The performance of the Nervos network itself is not enough to support large-scale applications, so there is a Stack solution. The Stack chain should be a POS mechanism, and network security is provided by the pledged BTC and CKB. Recently, many applications based on RGB++ have been launched. You can pay attention to the following participation angles.

Rooch @RoochNetwork (Global State Machine) Rooch's solution looks very large, and many tools are made in the move language. In summary, there are the following features:

1 Verifiable Application Container (VApp Container): The Rooch team has developed a VApp container based on the Move language, including MoveOS, Move standard library and development tools, providing application execution environment and state maintenance functions.

2 Root to Bitcoin: Execute Bitcoin blocks in the VApp container, verify UTXO and convert it into Move objects, and provide Bitcoin's off-chain smart contract solution.

3 Distributed State Tree Protocol (DSTP): Through the distributed state tree protocol, different subtrees are distributed in the P2P network to achieve parallel processing and interoperability between applications.

4 Asset Leap Protocol: Design a cross-layer asset migration protocol to solve the high transaction cost and long confirmation time problems on Bitcoin L1 and realize asset flow between L1 and L2.

They are currently holding a developer event: Rooch Network Early Builders Program. Interested developers can go and have a look.

ZKM @ProjectZKM Metis is a development; Bridgeless Bridge is very interesting. Many people are optimistic about it, probably because it has some unique features in ZK. The zkMIPS white paper has just been released: