> For the complete documentation index, see [llms.txt](https://docs.orbisprotocol.com/orbis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.orbisprotocol.com/orbis/technology/halo-2.md). # Halo 2 Halo 2 is the name of both a leading-edge zk-SNARK theory and its implementation. It was developed by the team behind Electric Coin Co., the inventors of Zcash. Halo 2 is a successor to Halo, and both systems are inspired partly by the zk-SNARK theories PLONK and Sonic, among others. Orbis Labs chose Halo 2 as the basis for our zk-SNARK implementations due to the following considerations. In no particular order: * Relatively stable and mature. It is audited, production ready, and used at scale in production. * Efficient proving algorithm. * Relatively small proofs which are not very computationally difficult to verify. * Rich ecosystem of tooling, SDKs, and reusable circuit code. * Does not require a trusted setup process and has no trust assumptions. Verifiers need not trust provers or any third party. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## 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, and the optional `goal` query parameter: ``` GET https://docs.orbisprotocol.com/orbis/technology/halo-2.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. 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.