14
Placing an Encrypted Call
In order to place a secure call, the following conditions need to be met:
• your partner has a CryptoPhone compatible device up and running
• there is sufficient GSM coverage
• the GSM operator supports ‘GSM data calls’ (technically called 9600
bit/s Circuit Switched Data or ‘CSD’)
To place a secure call, you can simply dial from the home screen and
press the “Call Secure” softkey on the left side. You can also choose
“Contacts”, select a contact and press “Call Secure”. Further you can
switch to the CryptoPhone screen by pressing the home key and dial di-
rectly (press the green Call button after entering the number).
The very first call after you switch on the CryptoPhone will take lon-
ger to be dialed after you press the green button, as the random num-
ber generator needs to be initialized and verified. After this you will
hear a bit of comfort noise in the speaker, followed by the normal ring-
ing tone. It may take longer than in unsecure mode before the secure
connection is established, 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 to 0 seconds, but
typically 4 seconds, depending on line quality. Once key setup is com-
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CryptoPhone
