IoT Device Security in MQTT
Different Levels of security in MQTTSecurity in MQTT is divided in multiple layers. Each layer prevents different kinds of attacks. The goal of MQTT is to provide a lightweight and easy-to-use communication protocol for the IoT.
Here is a high-level summary of security levels in MQTT
- Network Level – One way to provide a secure and trustworthy connection is to use a physically secure network or VPN for all communication between clients and brokers. This solution is suitable for gateway applications where the gateway is connected to devices on the one hand and with the broker over VPN on the other side.
- Transport Level – When confidentiality is the primary goal, TLS/SSL is commonly used for transport encryption. This method is a secure and proven way to make sure that data can’t be read during transmission and provides client-certificate authentication to verify the identity of both sides.
- Application Level – On the transport level, communication is encrypted and identities are authenticated. The MQTT protocol provides a client identifier and username/password credentials to authenticate devices on the application level.
- Authentication with Username and Password – The MQTT protocol provides username and password fields in the CONNECT message for authentication. The client has the option to send a username and password when it connects to an MQTT broker.
- Authentication with Client Identifier and X.509 Certificate – Every MQTT client has a unique client identifier. The client provides this unique ID to the broker in the MQTT CONNECT message.
Another possible authentication method is using the X.509 client certificate. The client presents this certificate to the broker during the TLS handshake.
- TLS / SSL – MQTT relies on the TCP transport protocol. By default, TCP connections do not use encrypted communication. To encrypt the whole MQTT communication, many MQTT brokers allow the use of TLS instead of plain TCP.
- Payload Encryption – This is done at the application level and not by the broker. This means that you can have encrypted data without having to configure the broker. It also means that data is encrypted end to end and not just between the broker and the client. However, this doesn’t involve any broker configuration or support this is likely to be a very popular method of protecting data.