SITP: Sealer Inscription Transfer Protocol

1. SITP Protocol

let's delve into the SITP (Sealer Inscription Transfer Protocol) for inscription transactions:

1. From and To Fields: Represent the source and destination addresses of the inscription transaction, respectively.

2. Protocol Field: Indicates which inscription protocol is being used.

3. Index Field: Represents the sequence number of the inscription.

4. Payload: The content encoding of the inscription transaction.

5. Proof Field: The proof data for the authenticity of the inscription transaction.

6. Version Field: The version number of the inscription protocol, used for future maintenance and upgrades.

The key features of the SITP protocol mainly include inscription services and the proof of inscription transactions. Inscription transactions are the basic units of the inscription protocol. Through the SITP, differences across various inscription protocols can be resolved. This not only facilitates integration into the Bitcoin inscription ecosystem but also allows for integration with other chains' inscription ecosystems, such as Solana and Avalanche.

To further ensure the effectiveness of inscription transactions, the SITP adopts an inscription message proof mechanism, which better implements the legitimacy verification of inscription transactions.

2. Verification Enginer

The design of the verification engine adopts a plug-and-play approach for validators, meaning different cross-chain transactions use different verification rule strategies. The verification engine determines which validator to use based on the rule address. Currently, the verification engine supports Go built-in validators and WASM virtual machine validators. Below, we introduce these two types of validators:

1. Go Built-in Validator: This validator is a conveniently callable validator provided by default rules. It's natively integrated into Sealer nodes. For example, for Ordinals inscription transactions, the node provides a default rule address, and the Relayer directly calls this default Ordinals verification rule to validate the cross-chain transaction.

2. WASM Validator: This validator uses the WASM virtual machine as an executor to perform validations. Thanks to the characteristics of WASM, this validator allows users to write verification rules in different languages, such as C, Rust, or Go. Additionally, WASM's performance is generally higher than many blockchain contract virtual machines, like EVM. Users can write the verification rules in their preferred language, compile them into WASM bytecode, and then deploy them on Sealer.

3. Validation Runtimes

A highly efficient and pluggable verification engine has been designed to support the trustworthy verification of inscription transactions submitted by Relayers. This engine validates proofs submitted by the corresponding application chains based on dynamically injected verification rules. Before integrating an inscription protocol, it is necessary to write and register verification rules and deploy them to the verification engine. In the Sealer Network, each inscription transaction must be validated by the network to prevent forgery or tampering. The verification engine manages multiple verification rules through smart contracts, checks the legality of different inscription transactions, and supports online upgrading and modification of verification rules. The workflow of the verification engine mainly includes the following three steps:

1. Protocol Parsing: Internal parsing of inscription transactions by the verification engine. Since all inscription transactions follow the SITP protocol, this step allows for parsing transaction information and verification proofs as input for the subsequent verification engine.

2. Rule Matching: The verification engine matches the corresponding verification rule script based on the inscription protocol type parsed in the above step.

3. Rule Execution: The core of the verification engine, mainly involving the dynamic loading of rule scripts through the WASM virtual machine, and then verifying the inscription transactions to determine their legality.

In summary, the Sealer Network's inscription transaction verification engine has several advantages:

1. Efficiency: The use of the WASM virtual machine ensures the high efficiency of rule execution.

2. Updatability: Verification rules can be quickly and cost-effectively updated in response to changes in different inscription rules.

3. Comprehensiveness: It meets the verification system of various types of blockchain inscriptions.

4. Security: Security restrictions are set on the WASM virtual machine, allowing it to only call functions and libraries permitted by the engine itself.