Quick Start Guide
www.cryptophone.de
IP
GSMK CryptoPhone 450
To initiate the key exchange go to
'Contacts', highlight the name of your
contact and select "Manage Keys" from
the menu.
You can now initiate the key exchange
by pressing the Invite button.
For each key exchange, five SMS
messages will be sent and received,
containing the public key material.
After key exchange is completed, you
will be asked to verify the new SMS key
by either a phone call or other means.
The six letters of the cryptographic
fingerprint of your key are shown on
the display. Read out the three letters
that are shown under "You say" and
verify that the letters your partner reads
out are the same as shown under
"Partner says".
You can now
exchange
encrypted
SMS messages with your
partner using the
'New Message' icon.
The SMS key is kept in the Secure
Storage and is used to generate session
keys for your future encrypted SMS
exchanges with this partner.
It can be renewed from the "Manage
Keys" menu.
Lock the Secure Storage
To lock the Secure
Storage, tap the
'Lock'
icon.
Emergency Erase
In case a capture of your phone by
unfriendly elements is imminent, you
can use the 'emergency erase' function.
It overwrites all key material and
subsequently the rest of the flash
memory of the phone.
You can access this function from the
'Lock' screen. Note that an emergency
erase will take several minutes.
Reset
To reset your CryptoPhone, remove the
battery, re-insert it and switch the
phone on again.
Cold Boot
If you want to switch to a different
Security Level (see ) or reset your
phone to factory state, so that a new
empty Secure Storage is created, you
need to cold boot your phone.
Please note that all data stored on the
phone will no longer be available.
The data is not securely overwritten in
memory, as it would be in case of using
the Emergency Erase function, and can
possibly be reconstructed by forensic
methods.
Data stored encrypted in the Secure
Storage area continues to remain as
secure as your passphrase.
To cold boot your phone, go to
Windows Settings System and tap
'Master Reset'.
The 'quality' indicator icon changes its
color depending on the delay and
overall quality of the connection.
If it stays orange or red, try to change to
a location with better network
coverage. If it stays red and your call has
dropouts or otherwise bad audio, try
calling again and try to find better
network coverage. Call quality can be
sub-optimal in fast moving vehicles.
Send a Secure SMS Message
Before you can exchange secure SMS
messages with a contact, you need to
complete a key exchange.
the cryptographic key exchange is in
progress. "Key Exchange" is shown on
the display. After key exchange is
completed, six letters are shown. This is
a cryptographic fingerprint of the
unique session key used during your
secure call. When in call, read out the
three letters that are shown under "You
say" and verify that the letters your
partner reads out are the same as shown
under "Partner says".
If they do not match, you should not
consider the line secure.
Optionally, enter up to two GSM phone
numbers of your contact if you want to
exchange secure SMS messages.
Tap 'Save' to store the contact. You can
edit the contacts later. Enter the name
and the corresponding CryptoPhone
number for the contact you want to call
securely.
You will recognize valid CryptoPhone
numbers by the 807. Note that
they can not be contacted from the
normal telephone network.
Make A Secure Call
Tap the 'Contacts' button, select the
contact and either use the 'Dial' button
or choose "Call Secure" from the menu.
If your partner is available, you will hear
a ring tone. When he picks up, you will
hear a special tone sequence, indicating
9
10
8
...
11
12
13
1
