export interface MultipassData {
    created_at?: string;
    [key: string]: unknown;
}
export declare class Multipass {
    private _encryptionKey;
    private _signingKey;
    private _initialized;
    constructor(secret: string);
    private _initializeKeys;
    encode(obj: MultipassData): Promise<string>;
    generateUrl(obj: MultipassData, domain: string | URL): Promise<string>;
    sign(data: ArrayBuffer): Promise<ArrayBuffer>;
    encrypt(plaintext: string): Promise<ArrayBuffer>;
    private _arrayBufferToBase64Url;
}