sodium_crypto_box_open

(PHP 7 >= 7.2.0, PHP 8)

sodium_crypto_box_open — Authenticated public-key decryption

sodium_crypto_box_open(string $ciphertext, string $nonce, string $key_pair): string|false

Decrypt a message using asymmetric (public key) cryptography.

ciphertext: The encrypted message to attempt to decrypt.
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_pair: See sodium_crypto_box_keypair_from_secretkey_and_publickey(). This should include the sender's public key and the recipient's secret key.

Returns the plaintext message on success, or false on failure.