Hezbollah has been warning its members not to use cell phones because they get targeted by using them too. Seems like the pagers were supposed to be the workaround for that.
Lots of pagers operate in one-way only mode. Towers transmit messages without expecting acknowledgement a few times, pager is configured to filter out and only alert on messages routed to its ID.
Sure, theoretically one can detect a receive-only radio, but its massively more difficult than detecting something which actively transmits.
Most pagers do, yes. They are also usually unencrypted. And due to the one way nature, even if they are encrypted, PFS (perfect forward security) is impossible. Meaning that if someone captures the encrypted messages they can decrypt them all the way back when the encryption key is obtained.
But the impossibility of any kind of location tracking is definitely a plus of one-way pagers. Not just for terrorists. I'd get one if there were still a network where I live. It'd be really nice to be reachable and not be tracked 24/7 for once.
While the messages are not encrypted, you just have your actual message coded. Have agreed on phrases and what not discussed out of band. Send dummy messages to throw people off and not know what is a real transmission or a dummy one. Is that numbers station just spouting gibberish or communicating with spies?
The market closes at 5, dinner at the hotel, Grandpa will bring home the wine, bring your hat. Charlie 5 Alpha 2 4 7 3 Bravo. Maybe this is just discussing someone's evening, maybe its coordinating a group action.
Many pagers are receive only. The tower has no idea who's listening; it just broadcasts out the messages that it's told to. Pagers are much less trackable than phones.
> Surely a pager message isn't transmitted from every tower everywhere.
They generally are!
Some systems required the sender to select a geographic region to increase bandwidth efficiency, or alternatively the pager owner to update their coarse-scale location with the operator after moving significant distances.
The latter is what the old Iridium satellite pagers did (do?), for example. (Not sure how the new GDB-based ones work.)
The new Iridium pagers are two-way as far as I've heard. Only the old ones were one-way.
I think the service is finally being decommissioned due to the Iridium Next satellites not supporting it anymore. It has been supported for more than a decade without onboarding new customers though.
> The new Iridium pagers are two-way as far as I've heard.
Apparently that's optional:
> Iridium Burst-enabled devices can be configured as receive-only so that no transmissions are made, a feature valued highly by some customer segments.
> I think the service is finally being decommissioned due to the Iridium Next satellites not supporting it anymore.
If that's the case, it would have been inoperable since 2017 – they deorbited the old satellites immediately after confirming deployment of the new ones.
That's exactly how they work, actually. Or at least worked, traditionally. There are assuredly some two-way pagers out there now.
But yeah, you'd usually pay for service in a certain (large) geographic area, and if you wanted to take your pager out of that area while on a trip, or if you moved, you'd have to let the pager company know so they could start broadcasting in the new area.
They might have watched The Wire: you page Alice, and she uses a public phone to call you. Undetectable unless you wire all public phones in the city, or someone is dumb enough to always use the same phone (which is what happens in the series; they eventually switch to burner mobiles).
To be fair, they rotate the burners in the series every 2 weeks and it takes the police more than a week to get up on the new ones.
It was cool to see that it was in fact an opsec fail (the guy buying the phones all over the country got lazy and bought too many from the same shop) to break through that. Pretty realistic. Like most of the wire in fact.
Although one thing in the wire I don't understand. Pagers are really easy to intercept, anyone with a scanner (with discriminator output) can do it and could do it in those times. I did it many times during the days when pagers were still in full swing. I really don't understand why they needed a court order for that (in season 1).
> Pretty realistic. Like most of the wire in fact.
The show creator worked for years as a journalist on the crime beat in Baltimore, I expect most of the opsec seen in the series comes from real cases.
> really don't understand why they needed a court order for [wiretapping pagers]
As others said, you need it from a legal perspective rather than a technical one. This is particularly true in the US, where the "fruit of poisonous tree" doctrine is pretty strict: if your evidence was not gathered in the proper manner, it must be discarded and it invalidates any further effort based on it. In specific, wiretapping is illegal even when done by authorities, unless they've been authorized by judges - the relevant US laws were tightened up after it emerged (with Watergate) that president Nixon was eavesdropping on his political rivals.
https://www.ynetnews.com/article/sya00qlswa