function public_encrypt($plaintext){
                $fp=fopen("./mykey.pub","r");
                $pub_key=fread($fp,8192);
                fclose($fp);
                openssl_get_publickey($pub_key);
                openssl_public_encrypt($plaintext,$crypttext, $pub_key );
                return(base64_encode($crypttext));
        }
        
        function private_decrypt($encryptedext){
                $fp=fopen("./mykey.pem","r");
                $priv_key=fread($fp,8192);
                fclose($fp);
                $private_key = openssl_get_privatekey($priv_key);
                openssl_private_decrypt(base64_decode($encryptedext), $decrypted, $private_key);
                return $decrypted;
        }