Transition to Wireless M-bus encryption mode 7
Stockholm, August 10, 2025 – In connection with the new radio directives from the EU, we will primarily transition to encryption mode 7 (from 5 previously) for wireless M-bus.
The change was already implemented in 2025 Q1 but has been voluntary until the new radio directive.
The Wireless M-Bus standard (EN 13757-4/EN 13757-3) defines several encryption modes that control how the payload in the telegram is protected. In more modern versions, they are mainly based on AES-128 (previously, simpler CRC protection or no encryption was also available).
Here are the main differences:
Differences in practice
- Encryption only (e.g. Mode 5) protects against eavesdropping but not against data modification.
- Encryption + authentication (e.g. Mode 7) protects against both eavesdropping and manipulation.
- The choice of mode is often governed by national requirements (e.g. MID, security profiles) and compatibility.
