Online PHP editor | output for Z6jTA

<?php $algo = 'aes-256-gcm'; $iv = random_bytes(openssl_cipher_iv_length($algo)); $key = random_bytes(32); // 256 bit //$data = random_bytes(1024); // 1 Kb of random data $data = "well hello there"; $ciphertext = openssl_encrypt( $data, $algo, $key, OPENSSL_RAW_DATA, $iv, $tag ); // Change 1 bit in ciphertext // $i = rand(0, mb_strlen($ciphertext, '8bit') - 1); // $ciphertext[$i] = $ciphertext[$i] ^ chr(1); echo(base64_encode($ciphertext)); echo("\n"); echo(base64_encode($tag)); $i = rand(0, mb_strlen($tag, '8bit') - 1); $tag[$i] = $tag[$i] ^ chr(1); echo("\n"); echo(base64_encode($tag)); $decrypt = openssl_decrypt( $ciphertext, $algo, $key, OPENSSL_RAW_DATA, $iv, $tag ); if (false === $decrypt) { throw new Exception(sprintf( "OpenSSL error: %s", openssl_error_string() )); } printf ("Decryption %s\n", $data === $decrypt ? 'Ok' : 'Failed');