import type { InputUTXO, SerializedUTXO } from "./model.js";
/**
 * Compute signature for nullifier derivation.
 * Matches circuit's Signature template:
 *   signature = Poseidon(privateKey, commitment, pathIndex)
 */
export declare function computeSignature(privateKey: bigint, commitment: bigint, pathIndex: bigint): bigint;
/**
 * Derive nullifier for a UTXO.
 * Matches circuit's UTXONullifier template:
 *   signature = Poseidon(privateKey, commitment, pathIndex)
 *   nullifier = Poseidon(commitment, pathIndex, signature)
 *
 * The signature-based nullifier ensures only the private key holder can spend.
 */
export declare function deriveNullifier(utxo: SerializedUTXO, pathIndex: number, privateKey: bigint): Uint8Array;
/**
 * Convert InputUTXO to the format expected by the circuit.
 */
export declare function inputUTXOToCircuitFormat(input: InputUTXO): {
    amount: bigint;
    pubkey: bigint;
    blinding: bigint;
    pathElements: bigint[];
    pathIndex: number;
    privateKey: bigint;
};