You can make it harder to do on accident, or to prevent someone from doing it for convenience (e.g. someone copying data to an insecure location to have easier access to do their job), but you can't stop a malicious actor from getting the data.
They could tunnel over DNS, they could use a camera phone and record the data on the screen, etc. The possibilities are endless.
That's a major point of exfiltration prevention, both because accidents are a real problem and because reducing the opportunity for accidents makes it easier to establish that intentional exfiltration is intentional, which makes the ability to impose serious consequences for it greater (especially against privilege insiders with key contractual benefits that can only be taken away for cause.)
Technical safeguards aren't standalone, they integrate with social safeguards.
But that’s not how it is advertised. Usually they claim is to catch hackers and mal intending employees.
Here are a few more (somewhat) related to this topic:
1.Joe Grand, “Advanced Hardware Hacking Techniques”, Defcon 12 http://www.grandideastudio.com/files/security/hardware/advan...
2.Josh Jaffe, “Differential Power Analysis”, Summer School on Cryptographic Hardware http://www.dice.ucl.ac.be/crypto/ecrypt-scard/jaffe.pdfhttp:...
3.S. Mangard, E. Oswald, T. Popp, “Power Analysis Attacks -Revealing the Secrets of Smartcards” http://www.dpabook.org/
4.Dan J. Bernstein, ''Cache-timing attacks on AES'', http://cr.yp.to/papers.html#cachetiming, 2005.
5.D. Brumley, D. Boneh, “Remote Timing Attacks are Practical” http://crypto.stanford.edu/~dabo/papers/ssl-timing.pdf
6.P. Kocher, "Design and Validation Strategies for Obtaining Assurance in Countermeasures to Power Analysis and Related Attacks", NIST Physical Security Testing Workshop -Honolulu, Sept. 26, 2005 http://csrc.nist.gov/cryptval/physec/papers/physecpaper09.pd...
7.E. Oswald, K. Schramm, “An Efficient Masking Scheme for AES Software Implementations” www.iaik.tugraz.at/research/sca-lab/publications/pdf/Oswald2006AnEfficientMasking.pdf
8.Cryptography Research, Inc. Patents and Licensing http://www.cryptography.com/technology/dpa/licensing.html
Why are you discounting these as valuable use cases?
In my experience, they're far more common than the determinedly-malicious actor. And they're far, FAR more common than the malicious actor who also (a) knows that the exfil monitor is there, and (b) has the technical prowess to circumvent it. (The analog hole is only _trivially_ usable for certain kinds of data.)
(I am continually frustrated by the number of people who claim that protection is worthless if it's potentially circumventable. In most situations, covering 90% of attacks is still worthwhile.)
People are saying that because it's misguided and potentially harmful.
Doing so is security theater, where the solution is scoped down to something incomplete but easier, and then everyone walks away happy they solved 90% of the smaller problem they chose to attempt.
Particularly with things like data exfiltration, this is potentially harmful because then you've organizationally blinded yourself.
Nobody wants to poke holes in their own solution, and so they stop looking.
But, hey, we're catching the odd employee accidentally sharing confidential documents via OneDrive.
Fast forward a year, and an entire DB gets transferred out via an unknown vector, nobody finds out about it for a couple months, and it's all "Oh! How did this happen? We had monitoring in place."
Go big, or run the risk of putting blinders on yourself.
Network security is a balancing act between prevention, detection, needed user and network capabilities and cost. If I have unlimited money or no limitations on hindering network usage I can make a 100% secure network - it's not even that expensive, just unplug it all.
It doesn't cover most attacks. That's why it's so misleading. It mainly just protection against incompetent people from accidentally sending out data.
- end up forcing you to lock it from the inside, and then crawl out the window
- have your friend who is visiting request a door-opening-token 24hr in advance through a JIRA ticket
- cause the power to go out once it's locked, also for security reasons
- force you to replace the keys with 'special' plastic ones from a new third-party vendor
- leave you stranded outside for a few hours because the door-opening system is having an outage
Those are the kind of trade-offs that will be made, not simply the act of locking the door.
'arcbyte over at https://news.ycombinator.com/item?id=19827012 does have a point - a lot of potential exfil risk is caused by companies doing their best to make it as difficult as possible for their employees to do their jobs.
This is not a good general principle, since it can be easily applied in contexts that (I would predict) many same individuals would vehemently disagree with. For example:
- Personal privacy is pointless, there are simply too many ways for governments/corporations/fellow citizens to find things out about you
- Strong taxation enforcement by governments is pointless, there are simply too many avenues for legal tax avoidance and illegal tax evasion
- Nuclear arms control is pointless, the knowledge of how to make a bomb and enrich uranium is widely available (I mean, if NK could pull it off, how hard could it be?)
Maybe data exfiltration prevention isn't a good policy, but I think you need a more nuanced argument than 'there are ways around it'.
They are not a guarantee that an incident cannot happen, though. They can only lower the rate at which incidents (privacy violations, tax evasion, nuclear proliferation) occur.
Same with exfiltration.
Copying files from one folder into another could do the job.
Oh, this was a fascinating read! Thanks for encouraging my perusal.
There is also research about using modem lights (even in the background of a room) to figure out what people are doing on their dialup internet connection. Those RX and TX LEDs are actually blinking at your data transmission rate.