Case Study: Establishing trust in M2M communications

The emergence of the Internet of Things and communication using wireless machine-to-machine (M2M) equipment (M2ME) promises to drastically increase the number of devices operating on any given wireless network. Because of fundamental deployment characteristics – such as highly distributed unmanned devices on decentralized networks – the deployment of M2ME demands a special emphasis on the security and trustworthy operation of the M2ME on the networks they connect to.
Let’s look at a few practical M2M uses.
Consider traffic cameras installed on highways and in intersections across the United States. These cameras require secure wireless local area network (WLAN) connectivity to the next camera to – for example – measure speed or relay traffic information. Or, for example, imagine that water utilities replace the monthly meter reader with a smart meter that collects data both to monitor monthly water usage and to raise a red flag on a remote monitoring device any time the usage fluctuates in a telltale way that suggests a potential water leak.
In each of the cases above, the M2M device is itself meant for unattended operation and remote functionality management. The device is also faced with natural, unpredictable connectivity to the core network that introduces security vulnerabilities for the M2ME and the wireless networks over which they communicate. Attacks might include physical attacks or tampering; falsifying meter readings; or data privacy and identity attacks, among others.
So with the opportunity for compromise at various intervals in the M2M communications, how can we be certain that information remains secure with the use of M2ME? InterDigital Inc. – a designer of advanced wireless technologies for data and voice communications – in collaboration with ETSI, 3GPP and other IEEE member organizations, is defining the two most important building blocks of deploying M2ME systems through the use of a trusted environment (TrE): first, by establishing local trust state control; and second, by conveying trust information to the network.
The first – local state control – occurs when establishing a secure system boot that includes all components and programs including operating system and security-sensitive software.This process includes verification and validation – meaning that the system can measure to verify its secure state supported by the TrE’s cryptographic capabilities. Such local state control, further supplemented with the communication of the state information to external parties, thereby provides verification of quantifiable measures for trustworthiness of the M2ME. The TrE also provides secure storage for its identity keys, credentials and authentication data. Protected interfaces additionally provide integrity and/or confidentiality protection to the data carried across them.
With these security systems simultaneously active, a verifiable “wireless fingerprint” is created. That fingerprint – the evidence for trust in a M2ME communication – is conveyed via a protocol called Semi-Autonomous Validation (SAV), which allows the network to validate the M2ME’s security state based on both the content of validation messages it receives from the M2ME and additional information from trusted third parties. This interplay of local and remote enforcement actions occurring during the processes of local verification and network validation opens up the doors for new security solutions protecting application-specific and value-added M2M communications.
Ultimately, given the nature of M2M scenarios involving unguarded and distributed devices, new security threats will continue to emerge and define new requirements that are best addressed by a balanced mix of device-centric trust and traditional enforcement of security properties to keep information safe and to establish human confidence in M2ME.