/**
 * Encode bytes to standard Base64 (RFC 4648).
 *
 * @param data - Bytes to encode
 * @returns Base64-encoded string with padding
 */
export declare function toBase64(data: Uint8Array): string;
/**
 * Decode standard Base64 string to bytes.
 *
 * @param str - Base64-encoded string
 * @returns Decoded bytes
 */
export declare function fromBase64(str: string): Uint8Array;
/**
 * Encode bytes to Base64url (RFC 4648 Section 5).
 * Uses URL-safe characters (-_ instead of +/) and no padding.
 *
 * @param data - Bytes to encode
 * @returns Base64url-encoded string without padding
 */
export declare function toBase64Url(data: Uint8Array): string;
/**
 * Decode Base64url string to bytes.
 *
 * @param str - Base64url-encoded string
 * @returns Decoded bytes
 */
export declare function fromBase64Url(str: string): Uint8Array;
