You will hear a bit of comfort noise in the speaker, fol-
lowed by the normal ringing tone. It may take a bit
longer than normal before the connection is made, so
please let it ring. After your partner has pressed the
Talk button on his end, you will hear a ditt-dutt ditt-dutt
sound that signals to you that the ‘key setup’ procedure
for the secure connection is in progress. Key setup may
take from 3 to 30 seconds, but typically 8 seconds, de-
pending on line quality. Once key setup is completed
you hear a »Ping« sound and can start talking to your
partner. In order to verify the authenticity of the key,
Please take a look at the display and read the three let-
ters under »you say« to your partner and verify the
three letters under »partner says«. The green SECURE
indicator is only visible when a secure call is estab-
lished. During all other times it is shown in grey with a
open lock.
Key Verification
Reading the three letters and verifying what your part-
ner says is meant to protect you against so-called ‘man-
in-the-middle attacks’ on the secret session key. The
letters are mathematically derived from the unique se-
cret key that is used during each call. By reading and
CryptoPhone G10 User Manual
8
CTQ
DGA
Sync Contacts and
Appointments
The CryptoPhone supports in principle the sync of con-
tact and calendar entries with a computer. You need to
be aware that in theory it might be possible to attack the
operating system of the CryptoPhone by supplying
manipulated data to your PC or exploiting unknown
problems in ActiveSync. GSMK does not recommend
to sync your CryptoPhone with a PC, especially if the
PC is connected to a network, for security reasons. If
you have high security demands and need to calculate
with a very sophisticated adversary, avoid to sync your
CryptoPhone with a PC. The CryptoPhone ships with
de-activated Active Sync functionality. You need to re-
activate the sync option manually in the CryptoPhone
to use it. To initiate a sync, connect the CryptoPhone
with the computer using the enclosed USB cable.
Note: Sync over IrDa (Infrared) and Bluetooth has been
disabled on the CryptoPhone as a precautionary secu-
rity measure. While we are currently not aware of ac-
tual problems with these sync options, there is a very
strong likelihood that such problems will arise in the
future. The main risk is that an adversary could poten-
tially gain wireless access to your device while it is in
your pocket or just on the desk in front of you.
CryptoPhone G10 User Manual
21
