Comment by polishdude20
Comment by polishdude20 3 days ago
How do you fit an explosive into a pager and still have the pager work? Like, aren't they already optimized to have everything for inside super tight?
Comment by polishdude20 3 days ago
How do you fit an explosive into a pager and still have the pager work? Like, aren't they already optimized to have everything for inside super tight?
> I bet you could use a CR1216 battery (1.6mm thin, 30mAh, instead if 34mm long and 1500mAh) instead and have quite a good deal of spare volume in the battery for an explosive.
I'd be fascinated if that was the physical vector...
However, tainting a component pre-integration seems a lot more likely than simply packing explosive in the case.
Israel inserts the compromised components upstream in the supply chain, they're duly assembled into pagers, which then make their way to Hezbollah, where they're inspected, look normal, and work normally, and are then distributed.
That would still require a firmware hack to presumably trigger though (incoming message stack to component trigger).
According to the manufacturer the pagers have a nominal battery life of about three months so it's not likely someone would actually notice if this number is cut in half or less.
An ESP32 is a power hog meant to be plugged into a wall. Here are the current requirements for the various modes according to [1]:
Active mode, 260mA to 790 mA (!)
Modem sleep, 20mA
Light sleep: 0.8 mA
Deep sleep: 10 uA
Hibernate: 2.5 uA
Compare that to something like an STM32U5 microcontroller [2]:
3.1 mA Run mode at 160 MHz
19.5 μA/MHz Run mode at 3.3 V
6.6 µA stop 2 mode with full SRAM
1.7 μA stop 3 mode with 16 Kbyte SRAM
0.5 uA standby mode with RTC
0.3 uA standby mode (24 wakeup pins)
0.1 uA shutdown mode (24 wakeup pins)
That results in a power consumption ratio on the order of 100,000,000. ESP32s are not efficient.
[1]: https://lastminuteengineers.com/esp32-sleep-modes-power-cons...
[2]: https://www.st.com/en/microcontrollers-microprocessors/stm32...
Because it takes a surprisingly small amount of high explosive to cause the kind of damage shown in the footage we’ve seen so far. All it would take is for the battery to be replaced with a combo package - part battery, part explosive. No need for additional internal space.
Disclosure: my first job was in the Australian Defence Science Technology Organisation, Materials Research Lab, Explosives Instrumentation Group.
If cost per unit isn’t a consideration, I suspect you can shrink the size of the electronic components used in the pager to make room for a 20 gram explosive charge.
Pagers—especially commodity models—aren’t profitable enough to warrant cutting edge tech with the latest advances in microelectronics. Lots of room to improve things if you are making a set of them at a loss.
One possibility is to replace part of the battery. The smaller battery can be designed to lie about its charge, or you can replace with a higher energy-density battery and use the space saved for a detonation system (perhaps even incorporating the battery itself into this) and a small quantity of high explosive, which is pretty stable and safe until detonated. Contrary to popular belief, high explosives are actually relatively safe, and usually even burn safely or are hard to ignite at all in some cases. Package it up into something that looks identical to an unmodified battery. Modify device firmware and battery control circuitry to detonate it on receipt of a specific signal and... boom.
Thinner (less durable, but who cares?) plastic shell to free up space for explosives, but would likely be obvious if someone opened it - which might be a common thing if these were being used as remote triggering devices.
If they were using a AA battery, replace the battery with something that provides you space to work (e.g. put in a AAAA or button cell that would provide appropriate power but lower capacity) because you don't really care if the battery life drops from months to weeks.
I can easily envision a scenario that would preemptively “explain” why the pagers are internally different from past models:
Supplier: “Hey, we’ve got a refreshed model of the pager you wanted to buy in bulk. Interested?”
Buyer: “I don’t know, how do they work?”
Supplier: “Same as the other ones, minus a bit less plastic protection. With the weight savings they’ve added a new hardened receiver that’s supposedly more secure and will keep communications private. Also, they are 50% cheaper per unit…”
Buyer: “Say no more. We’ll take them.”
Pagers, by definition, are likely to be older technology.
The internals could be replaced with modern smaller and lower-power equivalents, requiring a smaller battery, and saving enough space.
(Or maybe somebody just donated a batch of innocent-looking devices to 'the cause', or offered a bargain on some 'extra secure' pagers?)
No, a pager is optimized to be a case size that's comfortable for carrying and reading. The electronics could be the size of the smallest wristwatch, which is already dominated by its own form factor requirements, not the PCB + battery + display subcomponents that are scarcely the size of a nickel.
A typical pager is about 60 x 40 x 20mm. Much of this volume requirement is driven by the 16mm diameter 34mm long CR123 battery, a lot of it could be empty.
That battery is a relatively safe lithium primary chemistry, not a rechargeable Lithium polymer pounch or lithium ion cylinder that would risk fire and explode if the overpressure vents were omitted and the BMS corrupted, but the primary lasts for years.
I bet you could use a CR1216 battery (1.6mm thin, 30mAh, instead if 34mm long and 1500mAh) instead and have quite a good deal of spare volume in the battery for an explosive. If you filled the entire pager, that would be even more room, but much more easily detected.