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 108/112
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
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
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