User's Manual

USER MANUAL PREVIEW
PTM 535BZ – BLUETOOTH AND ZIGBEE GREEN POWER PUSHBUTTON TRANSMITTER
© 2022 EnOcean | www.enocean.com F-710-017, V1.0 PTM 535BZ User Manual | v1.2 | July 2021 | Page 115/121
D.1.5 Constant internal parameters
The RFC3610 implementation in PTM 535BZ derives two internal parameters – M’ and L’ –
based on the input data and uses them to construct A0_Flag and B_0_Flag which – together
with the iteration counter i – are required for subsequent processing.
The value of these internal parameters - listed in Table 36 below - is the same for all PTM
535BZ telegrams.
Parameter Comment / Description Example
M’
Binary encoded output length
M’ = (Output length / 2) - 1
0b001 (always)
L’
Binary encoded length field size
L’ = length field size - 1
0b001 (always)
A0_Flag L’ 0x01 (always)
B0_Flag (0b01<<6) + (M’<<3) + L’ 0x49 (always)
i Iteration counter 0x0000 (always)
Table 36 – Constant internal parameters
D.1.6 Variable internal parameters
The RFC3610 implementation in PTM 535BZ derives four internal parameters – Nonce, A0,
B0 and B1 – based on the telegram specific input data and the constant internal parameters.
These variable internal parameters - listed in Table 37 below - are then used together with
the security key to calculate the actual signature.
Parameter Comment / Description Example
Nonce
13 byte initialization vector formed as concatenation of
source address, sequence counter and 0x00 padding
0600001015E240000000000000
A0 A0_Flag followed by Nonce followed by 2 byte 0x00 010600001015E2400000000000000000
B0 B0_Flag followed by Nonce followed by 2 byte 0x00 490600001015E2400000000000000000
B1
Input Length followed by Input Data followed by 5 byte
of 0x00 padding
00090CFFDA0340000000010000000000
Table 37 – Variable internal parameters