How secure are mobile and Internet phones?

[Nick]

Been wondering as our BT landline is going ...

We used to use this for Bank transfers and wonder if the Internet and Mobile phones are safe?  I sort of presume that secure end to end encryption is being used?

VoIP technology is certainly safer than POTS (normally wired analogue phones) - it is end-to-end encrypted (where the other end is where the VoIP traffic enters the normal trunk system, which ISTR is ISDN-based around 64kB channels).

Tapping into an analogue phone is very very easy; much harder for VoIP.

However, as most attacks are via social engineering, it's better to concentrate on avoiding that.