With regard to noise, you can make it more manageable by building a graph. As you initially ID terrorists, you follow the graph and calibrate the signal. You don't have to enmesh everyone.
As someone was saying on Twitter, intelligence agencies should not want terrorists to start using steganography...which would make their passive traffic analysis much harder. But if they start censoring and banning encryption apps (which use metadata all in the clear), that's exactly what will happen.
Also, it seems most people live with the impression that "if only current apps such as Signal, Tor, etc" would be banned, that should pretty much put an end to encrypted, hidden communications, right? Wrong. Dead wrong. Right now they are being "lazy" and just use what's available to them, like Telegram and whatnot. But if those apps were actively banned, they would focus on building their own, perhaps with forked Signal/Telegram sources. But even without those, they could still commit to building their own solutions.
To give you an analogy, look what's happening with the Silk Road-like world. Authorities stopped Silk Road - like twice or third times already. But the underground online drug market is bigger than ever - it just split into multiple smaller markets. If that happened with drug businesses and drug delivery, it should be much easier to happen with "chat apps".
People would still want strongly encrypted apps especially if they were actively banned by oppressive governments.
Thus forcing terrorists to use Android or a desktop OS? Big whoop.
It's not to make it 100% foolproof, it's to make it so that any misstep would reveal them. In other words, make the whole of their communications system leaky _somewhere_ not necessarily everywhere.
I think it's becoming more clear that intelligence alone is not enough.
I'm also very worried that 10 years from now we'll have an even bigger problem than Daesh in the Middle East, even if Daesh is "wiped out" - Al Qaeda was wiped out, too, unless we forget. Daesh is much bigger than Al Qaeda was, which means they have many more relatives and children than Al Qaeda had - children that may rise up again in 10 years to avenge their fallen fathers and cousins.
France's reaction feels very much knee-jerk and 20th century thinkining - "Someone attacked us? Let's bomb the hell out of them then!". It kind of reminds me of when the French generals ordered their foot troops into the Germans' machine guns a century ago, because that was their 19th century thinking at the time.
This is a whole other discussion that also needs to happen, and I think a much bigger issue than the encryption one.
Conversely, if there is too much data and everything is hidden because there is too much, then why bother with the clamor for encryption? I mean, there is so much data, it's unfindable?
I think it was Poland and Russia sending cavalry and barely armed infantry into modern battle, not France during WWII.
Banks use encryption too.
The problem is there are too many signals, only made worse - not better - by mass surveillance (making the "hay" in which to find the needle bigger and all that). Here's an excerpt from Schneier in 2005:
> Let's look at some numbers. We'll be optimistic -- we'll assume the system has a one in 100 false-positive rate (99 percent accurate), and a one in 1,000 false-negative rate (99.9 percent accurate). Assume 1 trillion possible indicators to sift through: that's about 10 events -- e-mails, phone calls, purchases, web destinations, whatever -- per person in the United States per day. Also assume that 10 of them are actually terrorists plotting.
> This unrealistically accurate system will generate 1 billion false alarms for every real terrorist plot it uncovers. Every day of every year, the police will have to investigate 27 million potential plots in order to find the one real terrorist plot per month. Raise that false-positive accuracy to an absurd 99.9999 percent and you're still chasing 2,750 false alarms per day -- but that will inevitably raise your false negatives, and you're going to miss some of those 10 real plots.
> This isn't anything new. In statistics, it's called the "base rate fallacy," and it applies in other domains as well. For example, even highly accurate medical tests are useless as diagnostic tools if the incidence of the disease is rare in the general population. Terrorist attacks are also rare, any "test" is going to result in an endless stream of false alarms.
> This is exactly the sort of thing we saw with the NSA's eavesdropping program: the New York Times reported that the computers spat out thousands of tips per month. Every one of them turned out to be a false alarm.
99.9% and 99.9999% accuracy and you still get those huge false positive numbers. Even the drone strike program has much lower accuracy than that (yes, they do kill people based on "mostly assumptions" that they are terrorists, if that's news to anyone). I mean, in the US, they start spying on people if they have a >51% of not being an American (an amazingly low threshold - basically flipping a coin). So - maybe it's time to admit that mass surveillance is actually detrimental to catching these guys and that these spy agencies are hurting national security?
https://www.schneier.com/essays/archives/2005/03/why_data_mi...