Near field communication (NFC) is vulnerable to numerous networking attacks such as tag manipulation. In this work, a security protocol for the NFC chip is introduced to protect the NFC devices and associated data from several attacks. In addition, the NFC data exchange format (NDEF) message is modified with a certificate record and the alert mechanism is improved to enhance security. The modified secure protocol in the NFC system checks the authenticity of the incoming NDEF messages sender (by checking the signature record) and validity of the message/data (by checking the certificate), then if appropriate, stores the incoming NDEF messages in the device's memory for further processing. Matrix laboratory (MATLAB) simulation results suggest that the proposed protocol offers better security by detecting certificate modification, message modification, etc. The proposed secure technique for NFC can be extended to enhance security in mobile IoT devices.