USER MANUAL
PTM 215B – BLUETOOTH
®
PUSHBUTTON TRANSMITTER MODULE
© 2019 EnOcean | www.enocean.com
F-710-017, V1.0
PTM 215B User Manual | v1.9 | June 2019 | Page 72/85
B.
Address resolution for resolvable private addresses (RPA)
PTM 215B provides the option to obfuscate its identity by means of using resolvable private
addresses (RPA) as described in chapter 4.4.2. The following chapters describe how to re-
solve such addresses.
B.1.1
RPA resolution flow
The execution flow for resolving private addresses (RPA) is shown in Figure 42 below.
0000000...0000000
prand
104 Bit Padding (all zero)
24 Bit prand
Identity Resolution Key (IRK)
128 Bit Identity Resolution Key (IRK)
AES128
Don
t Care
hash
104 Bit Don
t Care
24 Bit hash
Figure 42 – Execution flow for resolving private addresses (RPA resolution)
The input to the RPA resolution flow are the
prand
part of the resolvable private address
field of the received telegram together with one (or several) locally stored IRK.
The receiver will then try for each locally stored IRK if the
hash
generated using the execu-
tion flow above matches the
hash
part of the resolvable private address field of the received
telegram. If it does then the IRK identifies the device from which this telegram originated.