Cryptofax HC-4220 | |
Fax encryptor The CRYPTOFAX HC-4220 was a fax encryptor developed by Crypto AG in Switzerland in the early 1990s. It allowed facsimile messages to be sent securely by any Group 3 fax unit via standard PSTN (analogue) telephone lines, at speeds between 2400 and 14,400 baud. The HC-4220 was available from 1994 until 2002 [4] when it was replaced by its successor the HC-4221 [2] [3]. The backwards compatible HC-4221 is smaller and is still available from Crypto AG today (2011). |
When turning the device on, it first performs a self-test. After approx. 10 seconds it is ready for use. If the battery in the controller is flat, the real-time clock (RTC) and the actual settings will have been lost. As a result, the unit resets itself to the factory defaults and the user is prompted to enter the new configuration. |