import type { CipherSuite } from '../stream/types.js';
/**
 * `CipherSuite` implementation for the stream construction using XChaCha20-Poly1305.
 *
 * Each chunk is encrypted with ChaCha20-Poly1305 using a HChaCha20 subkey
 * derived via HKDF-SHA-256 + HChaCha20. This is the recommended cipher suite
 * for `SealStream` / `OpenStream` / `SealStreamPool`.
 *
 * Pass to `SealStream` / `OpenStream` / `SealStreamPool` instead of constructing
 * this object directly. Use `XChaCha20Cipher.keygen()` to generate a 32-byte key.
 */
export declare const XChaCha20Cipher: CipherSuite & {
    keygen(): Uint8Array;
};