Dear all,
I just learnt that VoIP also does DTMF. Since today security is a very important concern, I started wondering: how is DTMF secured?
A series of services, including banks, offer DTMF interfaces, which imply dialing pin codes and the like. This would fall in the 'sensitive information' category. Now, how is security implemented, both in normal lines and VoIP? How can one ascertain that a given line (bearing in mind that you might happen to be across the world, and your voice-induced signals will run through a number of networks till they reach the machine that makes the authentication) is secure?
With VoIP, it seems even more complex. What are the conditions for DTMF to be transmitted? I understand the softphone or other gear must generate the signals; then, the VoIP provider must be able to translate the signals to the public telephone line.
I suppose DTMF security could be related to voice comm security: if it is possible to encrypt the data entering the broadband line at the user location, then decrypt it at the receiver location (and vice-versa), then tone signals would be safe. But can this be implemented? And how would a regular telephone be able to do it?
Regards,
Renato