Glossary · Automation software engineering and architecture
Secure software update
Also known as: Secure update
German: Sichere Softwareaktualisierung
In OT security, a secure software update is an update process that ensures only authentic, unmodified and authorized software is installed, typically by digital signatures, integrity checks, access control and protection against unauthorized downgrades.
- Software engineering
- OT security
In one sentence
A secure software update installs only authentic, unmodified and authorized software, using signatures, integrity checks and access control.
Example
The controller accepts a firmware file only if its signature verifies against the vendor's key, and the installation is logged with user and time.
How it applies
- Engineering: Components verify signatures before installation, protect keys, keep a fallback image and optionally prevent downgrades to vulnerable versions. IEC 62443 includes component requirements for update integrity and authenticity.
- Operation: Asset owners decide when updates are installed, test them where possible and keep records, as part of Patch management.
- Documentation: Describe how customers obtain updates, verify authenticity, install and roll back, and how long security updates are provided. The Cyber Resilience Act (CRA) makes such information a legal topic for products placed on the EU market.
Secure software update vs. software update
Any update changes software. A secure update adds guarantees about origin, integrity and authorization. The security mechanisms support, but do not by themselves prove, the security of the product.