import { Cipher } from '../../crypto/types.js';
import { PdfCryptFilter, CryptFilterOptions } from './base.js';
/**
 * Identity crypt filter that passes data through without encryption.
 * Used when no encryption is needed for specific content types.
 *
 * @example
 * ```typescript
 * const filter = new IdentityCryptFilter({ authEvent: 'DocOpen' })
 * const output = await filter.encrypt(data) // Returns data unchanged
 * ```
 */
export declare class IdentityCryptFilter extends PdfCryptFilter {
    /**
     * Creates a new identity crypt filter.
     *
     * @param options - Configuration options with authentication event.
     */
    constructor(options: {
        authEvent: CryptFilterOptions['authEvent'];
    });
    /**
     * Gets a passthrough cipher that returns data unchanged.
     *
     * @returns A cipher that performs no encryption or decryption.
     */
    getCipher(): Promise<Cipher>;
}