bartmanekul wrote:Yes, second offence at this, I think I warned you before Zippiracer.Interesting that you say texts. I dont know of any way of doing that except perhaps them installing something on your phone, that might forward texts silently to their number.
As for the calls, they can easily be recorded as people said, and theres no way of stopping that at their end.
However if your on about someone else listening to your calls, not the person your calling, then Im pretty sure this is very very high end stuff.
You are rather misinformed about GSM.
Short of someone having access to his phone, and being able to install software or some kind of bug without his knowledge, there are only a few ways to intercept calls and messages. In my expert opinion, nobody intercepted his calls through any spooky methods.
1. The person he called or sent a message to simply logged and recorded his conversations.
2. Someone at the phone company did this. (Unlikely, unless he is the target of a criminal investigation, the phone company has far better things to do than listen to your calls out of the billions of other calls and texts that pass over their networks daily)
3. He recorded his conversation and text messages himself and was careless with the storage medium.
4. He let someone else have access to his phone in order to make modifications or install extra hardware for the purpose of monitoring him. Either with or without his knowledge.
Edit: 5. Someone had a parabolic dish and a microphone to record his voice from a good distance. Someone used a nice telephoto lens and a good camera to watch him send text messages.
Edit: 6. His cohort (regardless of the facts) got a better offer from the dark side and ratted him out.
7. Man in the middle. (The least likely of all!)
GSM, the air gap is encrypted, the encryption scheme has been broken, but it is still very non-trivial to decrypt - it can take several weeks or more, unless you have some serious super computer power behind you - think NSA or other 3 letter government agency.
CCITT 7 - good old SS7, it's one hell of a complex beast. This is where your SMS passes through, along with all the dialing information, plus a whole array of other information about your phone, the network, blah blah. Breaking in to this transmission is NOT something you can do with your $500 radio shack scanner. You'll be needing a nice expensive modem for that, a down converter, spectrum analyzer, microwave antenna systems, some way to splice in to fiber or copper, amplifiers, cables, a digital capture card, a computer to work the data from the modem, some good coding skills to strip out the right timeslots, figure out the packet switched SS7 and ~maybe~ get a hit on to the phone you are wanting to monitor. I say ~maybe~ since SS7 does not even need to be on the same trunk as the call - it can be routed the opposite way around the world for all it matters. Not only that, it doesn't just openly identify your phone, the system might tell your phone to identify itself with a certain key one minute, then a different one a minute later - these changes happen often, far too often to keep track of without a lot of expensive kit.
Voice, unless you've got a good handle on the SS7, then you're going to have infinitely better luck sticking your finger in a wild cats butt hole than locking on to the right voice stream - again, you need the same equipment to get voice out your speaker as you would for the SS7 streams.
You will also need to be close to the target in order to sync in to the right cell tower - or get lucky and have a telco that likes to stream via satellite or some other easy signal path that can be handled from the comfort of your home.
There is no 'cheap' way to monitor GSM. You're looking at a few hundred thousand US dollars in equipment just to scratch the surface. If you need to monitor more than one bearer, and you usually do given the sheer number of people using that system, it'll cost you several million dollars. It doesn't come cheap.
Signed ex 'them'