T 5.33 Impersonating wrong senders on fax machines

Similar to writing letters using a false name and letterhead, it is possible to send faked fax messages. This can cause damage if the recipient assumes that the information is authentic and thus legally valid (c.f. T 3.14 Incorrect assessment of the legal validity of a fax).

Examples:

• Signatures on other documents can be scanned and printed onto the fax. The fax received shows no difference between a signature reproduced in this way and an authentic signature.

• The call number of the transmitting fax connection is generally sent during the transmission. It is possible, however, to impersonate a different call number. The processing of the receiver protocol is thus not a confirmation of the identity of the sender