Basic Hi Roy example of PHP encryption/decryption. #ApexSecurity

encrypted-hi-roy.php

<?php

$key = random_bytes(SODIUM_CRYPTO_SECRETBOX_KEYBYTES);

$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
$ciphertext = sodium_crypto_secretbox("Hi Roy", $nonce, $key);

$plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, $key);
if ($plaintext === false) {
    throw new Exception("Bad ciphertext");
}

echo $plaintext; // "Hi Roy"