USER MANUAL PREVIEW
PTM 535BZ
–
BLUETOOTH AND ZIGBEE GREEN POWER PUSHBUTTON TRANSMITTER
© 2021 EnOcean | www.enocean.com
F-710-017, V1.0
PTM 535BZ User Manual | v1.0 | May 2021 | Page 107/112
D.1.3
Obtaining the security key
All required parameters except the security key can be directly extracted from the received
message that shall be authenticated.
The security key
–
the common secret shared between sender and receiver
–
has to be ob-
tained via specific mechanisms.
There are three different ways to obtain the security key used by a PTM 535BZ module
when it is transmitting BLE telegrams:
◼
Via NFC (by reading SECURITY_KEY1 or by writing SECURITY_KEY2)
◼
Via the product label (which might provide information about SECURITY_KEY1)
◼
Via a commissioning telegram as described in
Chapter 3.4.3
D.1.4
Internal parameters
The RFC3610 implementation in PTM 535BZ derives a set of internal parameters for further
processing from the provided input parameters.
Again, there are two types of internal parameters:
◼
Constant internal parameters
These parameters are based on the high-level algorithm and telegram properties and
are the same for any PTM 535BZ telegram
◼
Variable input parameters
These parameters are based on the telegram-specific parameters and therefore de-
pend on the specifics of the transmitted telegram