SMS?
Is SMS any better on cell phones?
Honest question, not rethorical.
Pager communications in industrial environments often run over unencrypted channels, creating a hacker risk in the process. Industries such as energy, manufacturing, and transportation still make extensive use of pager technologies that have been superseded in other sectors of the economy. Researchers at Trend Micro warn that …
Even if the content is effectively information free (and you might be surprised how much can be deduced by pattern analysis) you have the problem, without decent encryption, that you cannot be sure of the source of a message or that it is untampered.
If you want to attack a critical worker (or get to them by attacking their family) you could do worse than sending a bleary-eyed recipient a message demanding they attend location X immediately.
You don't need to change the technology. Just encrypt the data sent over it.
Cloning a SIM doesn't really work that well, let's assume you did so and registered on the mobile network, the SMSC would deliver to your MS and not to the target's one, the message would get deleted off the system. (SMS being a point-to-point protocol.)
You would also have to NACK the SMS and then drop off the network sharpish, and not re-register until it had gone through to the real MS.
Industries such as energy, manufacturing, and transportation still make extensive use of pager technologies that have been superseded in other sectors of the economy. Researchers at Trend Micro warn that criminals might easily monitor the unencrypted pager data being sent by companies using a only a $20 dongle and some software defined radio know-how, as a blog post by Trend Micro explains.
It doesn't help that the operators are lax in their transmitter filtering so their transmitters spaff their shite over the 144-148MHz band making every nearby 2m amateur radio receiver (except the indestructable Icom IC-22A) squawk in sympathy!
Confidentiality or integrity of the message isn't much of a problem for many areas. However mobile phones have other security problems. The most obvious is that the mobile telephone network has to know where the receiver is. That's a really bad idea in some areas as carrying around a tracking beacon has heavy privacy implications.
Plus there are the obvious practical problems of the pager network having _much_ better coverage than mobile telephony.
Back in the day I did it with the earphone output of my Pro-26 and a laptop running some software, POCSAG I think it was.
It was like the days of loading games off cassette, twiddle the volume on the scanner and the gain on the laptop audio input and see if the next message was less garbled.