Functional Safety and Cyber Security: what’s the link between them?

Functional safety is an essential criterion for complex industrial plants. The aim is always to ensure that all the safety systems are operating properly, in line with their SIL. But what happens when a SIL device is also network connected?

Functional Safety Certification

A device can be subjected to a third-party assessment, to certify its SIL and so show that it meets the requisite functional safety standards, thus ensuring its compliance with the requirements of standard IEC 61508.

SIL certification is globally valid and is the most direct and authoritative way to demonstrate the complete reliability of a product in terms of its functional safety for the user, wherever a third party has specific accreditation for evaluating functional safety.

Reliability of network-connected devices

We can extend the idea of reliability to various objects vulnerable to hacking, for example, a SIL item that involves a network protocol, or certain accessory or diagnostic functions that communicate with a field network, or an SIL item that is connected via Bluetooth or Wi-Fi. These all need to be protected against malicious attacks, and so should also be fully reliable in relation to OT cyber security, in line with standard IEC 62443.

OT Cyber Security Certification

ISASecure® certification is the most frequently used official assessment scheme for certifying compliance with the requirements of standard IEC 62443, ensuring resilience in the face of attacks and based on values such as security, helpfulness, integrity, and confidentiality.

Cyber security certification is often required for functional safety (e.g. in the case of sensors that communicate with controllers via network protocols), but it is even more important for components that form part of an automation and control network designed to protect the system from external attacks.

The future of Functional Safety

So should a SIL item also be certified in terms of cyber security?

Most definitely. The future of functional safety is certainly moving towards a merger between compliance and the digitalization of safety devices.

Dual certification for an item to meet the requirements of both IEC 61508 and IEC 62443 ensures an even higher level of reliability, improves overall safety, and certainly increases the sales potential of the product. Although this system may appear rather novel, it is in fact readily accessible, and can create an immediate competitive advantage for many manufacturers.