This is a SR3 rules question/clarification. The SR3 book states that It's possible to read a broadcast signal with a Scanner, but if it's encrypted you need to decrypt the traffic before you can store it or understand it. Problem is, decryption takes several minutes, probably 5 or more, so how can you get realtime sound from a secured radio or cell phone? Does the setting assume that cell phones traffic is unencrypted?

If they do have to decrypt it, does the conversation need to last more than x minutes in order to succeed, and if it does succeed, do you get what has already been said or only the current voice/trideo?

It is also mentioned casually that deckers can intercept some cellphone traffic through the Matrix, but I couldn't find any rules on how this is done in practice. So assuming the group can either know the physical location of a target's cell phone or his cell phone number, how can a decker find the signal and "wiretap" any conversations throught the Matrix? I assume decking the cellphone provider itself it a possibility, but also very difficult.

IIRC we simply assumed that broadcast encryption was the same for all devices in a cell, otherwise it would be called "unicast encryption, right?

So crack the cell's encryption once (beforehand), and listen in to any call for the rest of the day.

Oh, so a cell in this case is the closest cell tower?
1) In wireless telephony, a cell is the geographical area covered by a cellular telephone transmitter. The transmitter facility itself is called the cell site. The cell provided by a cell site can be from one mile to twenty miles in diameter, depending on terrain and transmission power.

I thought the single device had it's own encryption, and that the legal provider had the key for it.

Is it assumed that most cell phones in 2050-2060 are not encrypted?

What leads me to question: IRL, the state enforce the law over the country.

In SR, there are multiple areas that are Under extraterritoriality. Couldn't then be cell sites who belongs to corporations and hence be outside the police juridiction, making people harder to track through their cell phones?

Yes... and the Corp cannot just go outside their extraterritorialty to kick in a door of a Decker that is hacking their stuff, because then THEY are also breaking the law.

That's why they hire ... Shadowrunners

And they said there was no work for Shadowrunners in the late 2070's.


Speaking of which.... when do we return to the dark shadows of Guangzhou?

In real life, the encryption key (password basically) is derived from a number that is individual for each SIM card, and a new key is generated when moving into a different cell (more precisely, when moving into a cell using a different Mobile Switching Center).

But SR encryption is not exactly based on real life, so we simply took "broadcast encryption" literally



The RL solution to that is easy, cell spoofers like the infamous Stingray. The GSM standard takes great care to make devices prove their legitimacy, but there are zero checks for the cell tower. In another *ahem* unfortunate design oversight in GSM, the cell tower (or anything claiming to be it) can just tell a connected device to turn the encryption off.
And even if getting a spoofer close to a target is not possible or would be noticed, the encryption is weak and uses short keys. GSM was very obviously built to be an open book for three-latter-agencies while preventing casual eavesdropping.

Sengir, do you have some sort of step-by-step how to wiretap a cell phone using SR3 rules and technology? If I know how it's handled in SR3 I can convert that to SR5 rules.

I would just play it that the decryption is the delay required to break the encryption. So listeners would hear everything with e.g. a 5 minutes delay.Maybe you need to listen in for some time recognize patterns and exchanged keys ecetera, and after that the deciphering starts. If the call takes less than 5 minutes, you still have to wait 5 minutes until the 1st second gets decrypted?

There is also a rule for wiretap a call via matrix. This also indicates that most calls seem to be made via matrix and the broadcasts you refer to are like microtranseivers you want to tap into, correct?

As I understand it, since you can't store the broadcast before it is encrypted (specified in the rules), if the call is terminated before the x minutes have passed, you don't have anything to decrypt afterwards. There is an indication that the calls are routed through the Matrix yes, but not rules for it. Micro-transceivers and normal transceivers (radios) are not routed through Matrix, and can only be intercepted with a (signal) scanner. Those at least are not per default encrypted, but they can be (I assume military and elite corp teams have encrypted comms). The cell phone description says it can either be intercepted like radios or by a decker through matrix, and that they have device rating 2 per default. That's pretty much it.

Phew, been some time since then...the basic idea was:
1.) Find the cell where the call will take place
2.) Crack the broadcast encryption:
make a Decryption Success Test against the Encryption Rating + 4. Electronic Warfaremay be used as a Complementary Skill for this test. The character must achieve a number of successes greater than half the transmitting device’s Encryption Rating, rounded up; otherwise, the attempt fails. The base time to decrypt a signal is (Encryption Rating x 5) minutes, divided by extra successes
3.) Sift through the data. I think we used some rules for security riggers there? Or just a Perception test?


"Indication" = "explicitly spelled out on p. 287 BBB"

In other words, you can use a Tap Comcall action...don't ask me why we didn't just do that...