import { Sr25519CryptoClient } from '@airgap/coinlib-core/protocols/Sr25519CryptoClient';
export declare class SubstrateCryptoClient extends Sr25519CryptoClient {
    constructor();
    signMessage(message: string, keypair: {
        publicKey: string;
        privateKey: string;
    }): Promise<string>;
    verifyMessage(message: string, signature: string, publicKey: string): Promise<boolean>;
}