sodium_crypto_box

Here's a quick example on how to use sodium_crypto_box(); where you have 2 people exchanging a $message, where person 1 encrypts it so that only person 2 can decrypt it, and be sure that person 1 actually sent it (without it being tampered with).<?php$keypair1 = sodium_crypto_box_keypair();$keypair1_public = sodium_crypto_box_publickey($keypair1);$keypair1_secret = sodium_crypto_box_secretkey($keypair1);$keypair2 = sodium_crypto_box_keypair();$keypair2_public = sodium_crypto_box_publickey($keypair2);$keypair2_secret = sodium_crypto_box_secretkey($keypair2);//--------------------------------------------------// Person 1, encrypting$message = 'hello';$nonce = random_bytes(SODIUM_CRYPTO_BOX_NONCEBYTES);$encryption_key = sodium_crypto_box_keypair_from_secretkey_and_publickey($keypair1_secret, $keypair2_public);$encrypted = sodium_crypto_box($message, $nonce, $encryption_key);echo base64_encode($encrypted) . "\n";//--------------------------------------------------// Person 2, decrypting$decryption_key = sodium_crypto_box_keypair_from_secretkey_and_publickey($keypair2_secret, $keypair1_public);$decrypted = sodium_crypto_box_open($encrypted, $nonce, $decryption_key);echo $decrypted . "\n";?>