Would it be possible to use the same technology of SSL with phones? Have the telco, who presumably knows the endpoint of the call can either apply an SSL certificate (or equivalent) to the call so that the receiver can confirm their validity?
Or, alternatively, much like how websites currently operate, the person making the call would have to attach their certificate which the receiver could check against CA(s). This would be nice because if certain CAs had rules where they wouldn't sign up certain numbers (telemarketers, politicians), you simply wouldn't use that CA to validate calls.
Or, alternatively, much like how websites currently operate, the person making the call would have to attach their certificate which the receiver could check against CA(s). This would be nice because if certain CAs had rules where they wouldn't sign up certain numbers (telemarketers, politicians), you simply wouldn't use that CA to validate calls.