/**
 * PDF decryption for reading encrypted PDFs.
 *
 * Supports:
 * - Standard Security Handler (V1/V2/V4/V5, R2/R3/R4/R5)
 * - RC4 encryption (40-bit and 128-bit)
 * - AES-128 encryption (PDF 1.6+)
 * - AES-256 encryption (PDF 2.0, V=5, R=5)
 *
 * @see PDF Reference 1.7, §3.5 - Encryption
 * @see PDF 2.0 (ISO 32000-2), §7.6 - Encryption
 */
import type { PdfDocument } from "./pdf-document.js";
/**
 * Initialize decryption for a PDF document.
 * Returns true if decryption was successfully initialized, false if
 * the password was incorrect.
 *
 * @param doc - The PDF document
 * @param password - User or owner password (empty string for no password)
 */
export declare function initDecryption(doc: PdfDocument, password?: string): boolean;
/**
 * Check if the document is encrypted.
 */
export declare function isEncrypted(doc: PdfDocument): boolean;