# sodium_crypto_aead_xchacha20poly1305_ietf_encrypt

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_aead_xchacha20poly1305_ietf_encrypt — (Preferred) Encrypt then authenticate with XChaCha20-Poly1305

### Descripción

sodium_crypto_aead_xchacha20poly1305_ietf_encrypt(
string `$message`,
string `$additional_data`,
string `$nonce`,
string `$key`
): string

Encrypt then authenticate with XChaCha20-Poly1305 (eXtended-nonce variant).

Generally, XChaCha20-Poly1305 is the best of the provided AEAD modes to use.

### Parámetros

`message`

  The plaintext message to encrypt.

`additional_data`

  Additional, authenticated data. This is used in the verification of the authentication tag appended to the ciphertext, but it is not encrypted or stored in the ciphertext.

`nonce`

  A number that must be only used once, per message. 24 bytes long. This is a large enough bound to generate randomly (i.e. random_bytes()).

`key`

  Encryption key (256-bit).

### Valores devueltos

Returns the ciphertext and tag on success, o `false` en caso de error.