# How Marble’s Layer 2 solution secures on-chain transactions Marble Layer2 adopts a multi-layer architecture design, completing data services, data submission, data sorting, and data validation through execution nodes. It achieves data synchronization and payment operations with BTC execution nodes through the on-chain EVM, Bitcoin light node contracts, and deposit-withdrawal contracts. External services are provided through Remote Procedure Call (RPC), multi-language SDKs, API interfaces, and on-chain data display queries via browsers. To ensure the security of Layer2 chains and the security of cross-chain transactions from Bitcoin chain to Layer2, Marble employs a series of technical means to achieve comprehensive decentralized security verification. Compared to other projects using centralized cross-chain or centralized verification methods, the technical implementation difficulty is higher, and the security level is greater. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://marblechain.gitbook.io/marble-whitepaper/marble-chain-btc-layer2/how-marbles-layer-2-solution-secures-on-chain-transactions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.