If it doesn't have backdoors now, it will soon. The remote-intercept capability mandate for land line phones is in the process of being extended to all commercial VOIP.
> Hardware-only plug & play box will never work here.
> But the absence of any easy-to-use/uncrackable/provably non-backdoored secure voice phone on the market is proof enough for me.
If you have to worry about being monitored by government, a super secret phone will not help you anyways. If it's worth doing, your room / furniture / clothes / windows are already bugged and all you say will be recorded before it hits the phone. I really think a provably secure phone is a non-issue.
If it's worth doing, you will be caught and tortured. "Extraordinary Rendition."
The worth of the phone is to prevent you from turning into someone who ought to worry in the first place.
Bugging room / furniture / clothes / windows is expensive.
The NSA is known to use voice recognition and keyword search. It is no longer necessary to already be a target in order to be extensively and intelligently eavesdropped on.
If it doesn't have backdoors now, it will soon. The remote-intercept capability mandate for land line phones is in the process of being extended to all commercial VOIP.
> Hardware-only plug & play box will never work here.
This looks like an example:
http://en.wikipedia.org/wiki/Secure_Terminal_Equipment
Or, for that matter, this:
http://www.gdc4s.com/content/detail.cfm?item=32640fd9-0213-4...
> I don't think you can prove any of it
Naturally.
But the absence of any easy-to-use/uncrackable/provably non-backdoored secure voice phone on the market is proof enough for me.