import { Signer, PublicKey } from '@mailchain/crypto';

/**
 * Signs a message using the Mailchain username with the identity private key.
 * @param key
 * @param username
 */
declare function signMailchainUsername(signer: Signer, username: Uint8Array): Promise<Uint8Array>;
/**
 * Verifies a message linking a username with an identity key is valid.
 * @param key
 * @param username
 * @param signature
 * @returns
 */
declare function verifyMailchainUsername(key: PublicKey, signature: Uint8Array, username: Uint8Array): Promise<boolean>;

export { signMailchainUsername, verifyMailchainUsername };