/**
 * Helper function to generate a unique requestId (UUID).
 * This uses the browser's crypto API for random UUID generation.
 */
export declare function generateUUID(): string;
/**
 * Helper function to get username from user object
 * @param nameObj the user object
 */
export declare function getNameString(nameObj: any): string;
/**
 * Helper function to decode an ArrayBuffer payload into a UTF-8 string.
 * @param data the array data to decode
 */
export declare function uint8ArrayToUtf8String(data: Uint8Array): string;
/**
 * Helper function to decode a CardKeyBlob v1 payload.
 * @param blob the v1 key blob payload
 */
export declare function decodeCardKeyBlobV1(blob: {
    seed: number;
    obf: number[];
}): Uint8Array;