# Circuits Both Hinkal circuits— EVM and Solana—are built to support privacy‑preserving, multi‑token transactions in a UTXO‑style model. Hinkal treats each token deposit as a *commitment*, a cryptographic hash that conceals the amount, token address, stealth public key and timestamp. Spending a commitment requires revealing a *nullifier* (a hash of the commitment and a signature) that proves ownership without exposing the spender’s secret key or linking the spend to other transactions. The circuits allow a user to aggregate multiple inputs and produce multiple outputs across several ERC‑20 tokens, all within a single zero‑knowledge proof. --- # 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://hinkal-team.gitbook.io/hinkal/technical-description/circuits.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.