export declare const SIGNATURE_LENGTH = 64;
/**
 * Produce a detached XEdDSA signature over `message` using a 32-byte X25519
 * secret key (a Carrier identity secret key). Returns a 64-byte signature.
 */
export declare function signDetached(secretKey: Uint8Array, message: Uint8Array): Uint8Array;
/**
 * Verify a detached XEdDSA signature against a 32-byte X25519 public key
 * (decode the userid to get it). Returns false on any malformed input rather
 * than throwing, so callers can treat it as a plain predicate.
 */
export declare function verifyDetached(publicKey: Uint8Array, message: Uint8Array, signature: Uint8Array): boolean;