"R. Mark Clayton" <> wrote in message
news

...
>
> "john reves" <> wrote in message
> news:ikas2p$qv8$...
>>
>> With recent political troubles in the middle east someone in the U.K.
>> would like to make
>> ** Secure ** telephone calls to arrange evacuation of persons who would
>> be a very likely target for hostage takers.
>
> You mean your uncle Saif?
>
>>
>> What would experts suggest using out of these various alternatives
>> available to them? A direct BT line, The 18185 indirect secondary service
>> on that BT line, the internet voip connection service, 'Voip Stunt' and
>> an Asda 'pay as you go' mobile connection.
>>
>> Security and privacy of conversation without any remaining local
>> government or security services listening in would be more important than
>> cost.
>>
> General
>
> I assume leakage at this end (where-ever that is) is not an issue; In the
> UK, GCHQ routinely listen in to anything RF they like and under RIPA the
> local dog warden can legally tap your landline. The international network
> is quite secure too, with only perhaps China and the USA able to seriously
> distort traffic to be sure of interception. The big problem is the local
> PTT which is often a branch of the local secret police (Iran, Libya etc.).
> In all cases use the sheer volume of traffic to make interception
> difficult (the best place to hide is in a crowd).
>
> The main options are: -
>
> 1. Inmarasat [with encryption]
>
> Advantages - geographically difficult to find due to satellite dish being
> directional.
> Network Secure, but downlink receivable by anyone.
> Disadvantages - expensive, needs aligned dish.
>
> Improve security - use bigger dish (narrower beam angle), hide it in a
> hole or drive out into the desert to use it..
>
> 2. Thuruya
>
> Advantages - does not (or should not) pass through local telecoms
> infrastructure
> Issues - now based in UAE, network might be compromised
> Disadvantages - expensive, may be possible to DF and locate, but keep
> calls short etc. and it should be OK.
>
> Improve security - don't display the phone, stay offline when not in use.
>
> 3. In net VOIP with encryption
>
> Advantages - cheap, probably just a soft phone
> Disadvantages - Needs IP connection, easily read by local PTT, encryption
> may instigate interest, local end can be located. Fails when local PTT
> pulls the plug, as has happened in many countries.
> Improve security - use a different PC and connection each time. Use a
> [public] wi-fi connection and then connect a headset or mobile to the
> laptop via Bluetooth. If you can skip the encryption then SIP enabled
> phones (e.g. recent Nokias) can make VOIP calls directly over wi-fi (no
> GSM transmission and IMEI not broadcast). Use a new account each time.
>
> 4. Buy a local (or third country) PAYG phone and call it from another.
>
> Advantages - cheap (not the calls though), portable, inconspicuous
> Issues - call interceptable, however the local PTT will have problems
> sorting the wheat from the chaff
> Disadvantages - Fails when local PTT turns off net, as has happened in
> many countries.
>
> Improve security - only switch on to make calls, use in different busy
> location each time. Get phones on the same service provider and then
> there is more chance calls will route in over private networks.
>
> 5. Landline
>
> Advantages - cheap and there are lots of them
> Disadvantages - routinely tapped by dodgy regimes, traceable.
>
> Improve security - only make arranged calls to / from public call offices
> or say cafes or restaurants at set times. If receiving calls use a TAM to
> see if line compromised.
That's an interesting list of options there that you've suggested.
Another option is an encrypted data radio link using HF radio (between 3 -
30MHz). Signal propagation between the UK and Libya should be reasonable
for much of the day as long as you use an appropriate part of the HF
spectrum. The problem here is that it's easy to direction find if you are
within ground wave range of the transmitter). Plus you would need an
appropriate licence to use that part of the radio spectrum from both the UK
and Libyan authorities if it's being used for a 2-way link.
I think this is only a last resort option to be honest and is probably not a
very sensible suggestion.