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 82/85
The execution sequence would then be as follows:
X_1 = AES128(B0, Key)
X_1 = AES128(49B819000015E25D0400000000000000, 3DDA31AD44767AE3CE56DCE2B3CE2ABB)
X_1 = 41ef09792ae152ae52c671435c1f247d
X_1A = XOR(X_1, B_1)
X_1A = XOR(41ef09792ae152ae52c671435c1f247d, 00090CFFDA035D040000110000000000)
X_1A = 41e60586f0e20faa52c660435c1f247d
X_2 = AES128(X1A, Key)
X_2 = AES128(41e60586f0e20faa52c660435c1f247d, 3DDA31AD44767AE3CE56DCE2B3CE2ABB)
X_2 = 8d89e733da516ae3e08f9e30184909fc
S_0 = AES128(A0, Key)
S_0 = AES128(01B819000015E25D0400000000000000, 3DDA31AD44767AE3CE56DCE2B3CE2ABB)
S_0 = 3f736fcc8bcaf2d4aabca0260fab7976
T_0 = XOR(X_2, S_0)
T_0 = XOR(8d89e733da516ae3e08f9e30184909fc, 3f736fcc8bcaf2d4aabca0260fab7976)
T_0 = b2fa88ff519b98374a333e1617e2708a
The calculated signature is formed by the first four bytes of
T_0
, i.e. it is
B2 FA 88 FF
.
The calculated signature matches the signature that was transmitted as part of the pay-
load. This proves that the telegram originates from a sender that possesses the same secu-
rity key and the telegram content has not been modified.