Attacking Tor: How the NSA targets users' online anonymity

http://www.theguardian.com/world/2013/oct/04/tor-attacks-nsa-users-online-anonymity

by brkcmd • 13 years ago

654 175 13 years ago

theguardian.com

aroch• 13 years ago

At least according the the slides, Tor appears to be safe for the most part. Which is good.

mcphilip2• 13 years ago

edit: removing meta discussion about flagging. the story should get the attention. apologies for the distraction.

kevinh• 13 years ago

There's another article from the Guardian on the NSA regarding Tor in the #6 slot on HN. This is in the #3 position.

I think you're overestimating the impact.

Edit: This article is now in the #1 position. Flagging isn't hurting these articles any.

tptacek5• 13 years ago

I don't think this is being flagged. I flag soap opera NSA stuff for instance, but wouldn't flag this.

mcphilip2• 13 years ago

It was at mid second page with 10 up votes after 35 minutes when I made this post originally.

TeMPOraL• 13 years ago

Maybe it's time to make flagging public, Quora-style?

eli• 13 years ago

1) It's currently first on the front page 2) Complaining about voting is really tedious to read about

pc86• 13 years ago

Almost as tedious as reading complaints about complaining about voting :)

tptacek5• 13 years ago

Metacommentary:

I've taken a jaundiced view of "liberation tech" efforts in the past and this is as good an illustration as any of why. Among "amateur" libtech projects, Tor is about as good as you get --- an active community, extremely widespread use, technical people with their heads screwed on right and as much humility as you can reasonably expect of people whose projects are (candidly) intended to thwart world governments.

If Tor can't provide meaningful assurances (here, there's a subtext that Tor actually made NSA's job easier), you'd need an awfully convincing reason for how you're going to do better than they are before "liberating" the Chinese internet, especially given that it your users who assume the real risks.

twoodfin3• 13 years ago

here, there's a subtext that Tor actually made NSA's job easier

Are you reading anything from that subtext beyond, "Tor has a high concentration of the kind of users we're interested in, so let's keep it a juicy target rather than squeezing too hard?"

rz2k• 13 years ago

As I understand it, which admittedly isn't well, it made surveillance jobs easier when its users mistook anonymity and privacy. That is, sending something through the tor network means that it's more likely that your traffic is going through a node belonging to a group that records everything than if your traffic randomly found a point to point route across the internet.

I don't see how using the Tor network could make you less anonymous, unless as you point out, it's use suggests a user's greater likelihood of sending and receiving interesting information.

It hurts the system that exit nodes have been targeted for content that other users were responsible, but from how I have read, Tor can provide people meaningful anonymity that is difficult breach.

As an aside: What is the effect of such parenthetical statements? I think they just create a vague idea of uncertainty and fear. If there is a vulnerability, there has to be a mechanism, not just a sense of omnipotent government surveillance.

Maybe that mechanism is the probabilistic likelihood of an organization controlling a large portion of the Tor nodes' ability to identify users. Maybe it's a flaw that has been surreptitiously put into the source code. I'm pretty sure more people who know would suspect the former as far more likely than the latter. It's easier to address the questions when you know what the parenthetical utterance was even referring to in the first place.

jlgreco5• 13 years ago

I don't know that it really is subtext here, but I suspect that Tor has many people communicating electronically where they would otherwise refuse to do so at all. In other words, "Normally I would refuse to talk about this on the internet and would meet you in the back of the bar instead, but I trust Tor so let's discuss this now."

It therefore puts communications that previously would not have been available to the NSA into the realm of things that the NSA can access.

option_greek• 13 years ago

What chance does a ragtag team of people from various backgrounds working part time on a open source project have against a determined enemy with billions in funding and hordes of PHDs working full time with single goal of violating privacy of netizens.

llamataboot• 13 years ago

A better chance than one would think from that phrasing, as there are a lot of highly motivated and intelligent people working on privacy tech.

gohrt• 13 years ago

That's entirely not the point. Even with 1000x the amount of funding, TOR would still be theoretically proven to be insecure. Only physicially secure hardware (including cables and routers) stands a chance against side-channel traffic analysis.

cmiles74• 13 years ago

I didn't read it that way at all, in fact, it sounds like Tor is sufficiently robust that a good number of NSA employees were tasked with finding exploits. In terms of the exploits found, it looks like all were against the browser.

  Tor is a well-designed and robust anonymity tool, and 
  successfully attacking it is difficult. The NSA attacks we 
  found individually target Tor users by exploiting 
  vulnerabilities in their Firefox browsers, and not the Tor 
  application directly.

tptacek5• 13 years ago

Tor enabled them to filter down Internet traffic to a subset, and then they simply violated the security premise behind real-world Tor usage (that the rest of the stack was secure) to pierce the veil completely.

I'm not indicting Tor. The opposite. But in Iran, China, or Belarus, you don't get to call a foul ball when your libtech stack breaks somewhere you weren't working on.

And again, my concern isn't Tor, but the (far more amateurish) things people come up with as new Tor alternatives to e.g. "circumvent the great firewall".

The principle I'm trying to communicate is that there's a degree of chauvinism implicit in amateur libtech --- that despite the billions of dollars any real country can leverage against Internet privacy, indie developers have a fighting chance against Iran, because after all they're just a tinpot dictatorship.

The other more general principle I try to communicate is that it doesn't matter how nice, or even how necessary, any given bit of security technology is. What matters is the engineering: will it work as deployed. Not having a better answer doesn't change the engineering fact of whether the best current solution is viable.

autodidakto• 13 years ago

I don't think your fears are justified by the article. The first thing you read is a pull-out quote that says:

Tor is a well-designed and robust anonymity tool, and successfully attacking it is difficult.

Maybe you're referring to:

The very feature that makes Tor a powerful anonymity service, and the fact that all Tor users look alike on the internet, makes it easy to differentiate Tor users from other web users.

Your kind words about the Tor project are accurate, but they have never claimed that it's possible to reliably hide Tor use.

The next sentence is:

On the other hand, the anonymity provided by Tor makes it impossible for the NSA to know who the user is, or whether or not the user is in the US.

There is no Tor exploit or new information here. The NSA has enough resources to recognize Tor users in the USA enmasse, as well as single-out individual connections. From this point on, FoxAcid works the same whether you're using Tor or not.

tedks3• 13 years ago

(here, there's a subtext that Tor actually made NSA's job easier)

I'm not sure how you reached that conclusion.

The slides mention that Tor is:

* Very difficult to identify on the network-level, since Tor-tls traffic is indistinguishable from Apache-tls traffic as of 2011

* Impossible to fully deanonymize

* Only exploitable via a handful of browser exploits.

Further, later in the "Tor is the King" slide deck, there's this rather glowing endorsement of the TAILS livecd:

"Tails... adds severe misery to CNE equation."

...which is what you'd expect, given that TAILS is entirely ephemeral, and so all of their callbacks and APT-style attacks are useless against it.

I had previously considered TAILS a rather "amateur" system myself, because of the glut of livecds bundling Tor. But it turns out they're actually adding severe(!) misery to the NSA's exploitation team! I'm downloading the TAILS cd now so I can switch over to using it in a VM rather than running Tor Browser Bundle on my own machine.

boon2• 13 years ago

link: https://tails.boum.org/download/index.en.html

codygman• 13 years ago

Will tails still only use ram and no disk within a vm? If not, you'll just have a slightly better tor browser bundle (plus other features) right? I always thought the "ram only" portion of tails was one of the biggest anonymity wins.

dsl3• 13 years ago

TAILS will detect it is running inside a VM and warn you not to do it.

I know quite a few folks who are sitting on escapes for popular VM products. They are not at all uncommon.

I would be absolutely shocked if the NSA's little toolkit didn't detect virtualization, pop out, and backdoor the host OS.

ris2• 13 years ago

Even TAILS worries me slightly. Why? Homogeneity. The same thing that makes a freshly booted TAILS "clean" and exactly the same as any other freshly booted TAILS also means that it's a "known quantity" to an attacker.

A lot of obscure vulnerabilities that would normally require a "perfect storm" to be used together to compromise a system are much easier to construct once you know a lot about the target system. And it would be well worth the time for an attacker to develop an exploit that would work against all TAILS users.

In the same way the Firefox heap spraying attack was specifically targeted against users of the Tor Browser Bundle. There, homogeneity was a large part of victims' downfall. TAILS is arguably many times more homogeneous.

ASLR and related technologies are a (very very basic) start but we may not have better answers to things like this until we have the likes of binary diversity as described in http://lwn.net/Articles/565113/ being usable (Even then, a final binary compilation stage would need to be taken by an application user before use).

Edit: and yes, you don't need to point out that the TBB vulnerability did heap spraying in Firefox's JIT and so binary diversity would probably have been minimally effective.

makmanalp• 13 years ago

Speaking of which, now is probably a great time to mention that the Berkman Center is doing an open call for fellowship applications:

http://cyber.law.harvard.edu/getinvolved/fellowships

And I'm sure the EFF is looking too.

aestra• 13 years ago

I wouldn't really consider Tor an amateur libtech product since the basics of the underlying technology (onion routing) was developed by the US Navy.

Here's the original patent from 1998:

http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=...

anologwintermut3• 13 years ago

This is one way the NSA can attack Tor. if they just want to de-anonymize a connection, not get access to the content, (.e.g to locate the Silk Road Sever), in theory they can just analyze all their passively collected data form major fiber backbones to identify and locate the user.

Tor, including hidden services, was never designed to protect against someone who could observe all or almost all traffic in the Tor network. Given that data, it's rather easy to correlate timing information. Indeed, Tor fundamentally allows this since it aims to be a low latency network.

Given the NSA's extensive tapping of key fiber lines, we should assume they can actually observe the necessary traffic.From the original paper announcing Tor: "A global passive adversary is the most commonly assumed threat when analyzing theoretical anonymity designs. But like all practical low-latency systems, Tor does not protect against such a strong adversary." --- Tor: The Second Generation Onion Router [0] [0] https://svn.torproject.org/svn/projects/design-paper/tor-des...

elwin4• 13 years ago

The more we learn about the NSA's capabilities, the more it seems like the Manhattan Project. They are developing the "cyberwarfare" equivalents of weapons of mass destruction. This exploit delivery network goes so far beyond any legitimate purpose it might serve that it belongs in the same moral category as hydrogen bombs.

EDIT: The above is somewhat hyperbolic and unclear. The NSA's capabilities may have legitimate uses. Similarly, there may be legitimate military uses for nuclear weapons. But building nuclear weapons creates the risk of worldwide nuclear destruction. Similarly, building this kind of highly efficient exploit system creates the risk of destroying all Internet security. The potential destruction far outweighs whatever good the weapons might accomplish. That is why I said they belong in the same category.

twoodfin3• 13 years ago

I think that's a pretty serious exaggeration. Designing tools to let you spy on Tor traffic has to be in a separate category from designing bombs that could kill millions.

Besides, are there no ends that could justify these means? I think the means are altogether reasonable given the ends. Put aside whether you think the NSA is genuinely pursuing its national security mission: If it were, wouldn't it make perfect sense to figure out how to attack Tor?

res0nat0r• 13 years ago

Sucks you are being downvoted for not agreeing with the hyperbole, but I think you are correct.

The NSA's job is to spy on things. TOR represents a place where illegal things occur, so it is a perfectly reasonable thing that they would be tasked with trying to stop such illegal things there.

elwin4• 13 years ago

Attacking Tor by passive analysis is one thing. Installing spyware, creating a botnet, and making the infection process quick and easy is another. There might be some justification for the former. The latter is too risky.

bcoates2• 13 years ago

The Stasi and the Gestapo were genuinely pursuing a national security mission. They also did more self-inflicted harm to Germany than the A-bomb did to Japan from the outside. He's not exaggerating the amount of damage an intelligence agency can do.

vezzy-fnord• 13 years ago

Hardly. The NSA's techniques, as described thus far, appear to be your basic computer security fodder. The same techniques that any modest black hat could do.

The difference is in the scale and dedication.

MichaelMoser123• 13 years ago

Maybe the NSA cyberwar effort did not produce new earth shaking insights; the manhattan project did that of course. Now both efforts may be compared in terms of their price tag: both did cost billions of tax dollars to implement.

Interesting that instead of reaching out for the stars we turn inwards - snooping as the new frontier that is pushing technology forward, now here is a great prospect ...

danso• 13 years ago

This accompanying article has useful context: http://www.theguardian.com/world/2013/oct/04/nsa-gchq-attack...

But the documents suggest that the fundamental security of the Tor service remains intact. One top-secret presentation, titled 'Tor Stinks', states: "We will never be able to de-anonymize all Tor users all the time." It continues: "With manual analysis we can de-anonymize a very small fraction of Tor users," and says the agency has had "no success de-anonymizing a user in response" to a specific request.

So only with "manual analysis" can intel agencies have any success, and that appears to be with a small subset of users who have other vulnerabilities. But when targeting a specific user, the NSA appears to have had no success in de-anonymizing them.

lambada• 13 years ago

This needs to be higher. I think this was the best scenario anyone who knows Tor could hope for. The attacks against Tor, when used correctly, are well understood. And, assuming this presentation is accurate,the capabilities of adverserial semi-global attackers aren't much different from what we were expecting.

I would love to see if they have similar slide-decks for I2P, which is often compared with Tor for Hidden Service/eepsite usage.

ktr100• 13 years ago

On page 5 of the 'Tor Stinks' full document is a clipart picture of a terrorist.

So... Somewhere in the bowels of the NSA is a graphic artist that slaps beards and guns to stock clip-art. fun job.

http://www.theguardian.com/world/interactive/2013/oct/04/tor...

galapago• 13 years ago

This kind of news should encorage people to create and use better tools for find and fix vulnerabilities in software.

spindritf• 13 years ago

So how does Tails[1] stack up? It seems to thwart most of those attacks.

It block non-anonymized traffic and makes permanent changes difficult. OTOH, privilege escalation bugs happen frequently on Linux.

https://tails.boum.org/

steveklabnik2• 13 years ago

According to the article,

"Tails... adds severe misery to CNE equation."

conductor• 13 years ago

Once the computer is successfully attacked, it secretly calls back to a FoxAcid server, which then performs additional attacks on the target computer to ensure that it remains compromised long-term

It would be nice if somebody could honeypot them to find out the vulns and malware types they are using.

antocv2• 13 years ago

How so I get on the list of most interesting persons so I can setup my honeypots? do I have to be jacob appelbaum or assange?

what freaked me out is that they deliver sensible exploits for techie people. go damnit.

coldcode• 13 years ago

Sure these folks are smart and have all sorts of powerful weapons; what are the odds that someone out there could successfully repurpose some of these weapons? What is the likelihood that vulnerabilities exist in the NSA's systems? We can never know since it's all secret. If someone does take over these systems we wouldn't know that either.

elwin4• 13 years ago

Historically, different nations' intelligence agencies have often infiltrated each other. I'm sure someone will eventually gain access to the NSA's weapons, but I think they would be more likely to steal details to add to their own systems than "repurpose" the NSA's.

wil421• 13 years ago

I am loving every minute of this NSA-Gate or Snow-Gate. Nothing like holding GOVT accountable for decisions they make behind closed doors, decisions that had an impact on the whole world not just US citizens.

Its also great all the technical details that are being released about how they Intel Agencies collect data. Its all fascinating.

kilroy1232• 13 years ago

Sounds like, if you're going to do something very sensitive on tor, you need to:

- always have an update to date version of tor bundle!

- compile the bundle yourself from source

- run it virtually, and always roll back to a clean snapshot (before installing it tor) when done

- if possible use from a network that is not your own (open wifi, public wifi, etc.)

- spoof your mac address

- do not run JS, Java applets, etc.!

I know this seems extreme, but from what I read, it's the best you can do to protect yourself.

bryze• 13 years ago

Yeah, I was wondering if a virtual machine is safe from malicious attacks, though. Can anyone comment on the feasibility of this method as fail-safe?

shabble• 13 years ago

Ideally you'd want to be running Tor with transparent proxying of all traffic on a physically separate (and locked down) host. I believe there are guides on how to do all that on a raspberry pi out there.

On your primary browsing/whatever machine, I believe (but have not exhaustively researched) that it would still make sense to run inside a VM/container, because that would provide a much more 'generic' set of system characteristics (MAC address, clock jitter stats, CPUinfo, etc) than your actual hardware. It does provide a greater attack surface, so you'd have to weigh up the value of potentially masking physical identity vs likelihood of gaining root due to VM exploits.

There's also the risk of overconfidence because of these measures, which might lead you to overlook important details in the host OS, or in your communication habits.

sitkack3• 13 years ago

There are plenty of ways to breakout of a VM. What if the VM has a filesystem that is readonly by the host?

Drive by download, cookie fs drop, etc. Attack the indexing server, file previews, etc.

You really want to run the VM on an external host like a raspberry pi and the VM should different than the host running Tor.

Tor should really be rewritten in a Coq proven Haskell program.

pyre2• 13 years ago

It's probably the best you can do, but it still doesn't prevent your anonymity from being compromised. As soon as the malware is installed, it can phone home, even if you end up wiping it after you are done.

sitkack3• 13 years ago

The malware would have to escape the virtual machine. The VM needs to be firewalled off from the host and NOT have the host <=> guest tools installed.

chakalakasp4• 13 years ago

If you are doing something that would make the NSA interested in you (and I would highly highly discourage that), you'd need to focus more on tradecraft. Get the laptop from a source that can't be traced to you, like a thrift store in a city where you don't live or normally frequent. Disguise yourself, pay in cash, and either make sure there are no security cameras or wait a good year before you do whatever you are going to do (nobody keeps camera data longer than that). When you do whatever you are doing, use a Live CD like tails. Disguise yourself. Wear gloves. Go to a city you don't live in or frequent regularly, and only use cash during the trip. Park a long distance from your wifi source where there are no cameras and walk to where you will access the wifi. Use a cantenna to hit an open wifi some distance away, preferably a public connection like a busy coffee shop. Do whatever you are going to do. Walk back to your car, drive to a nearby town, smash the laptop and dispose of in a dumpster. Drive home.

blake80863• 13 years ago

This is such random advice. What threats are you defending against here?

"Wear gloves": Why? Are you thinking someone will pierce the veil of all these other precautions but then be stymied when they find a smashed laptop with no fingerprints on it?

"Sir, we followed him for a year, watched him buy a laptop and use it in a park, but when we recovered the laptop from the dumpster, there were no fingerprints on it!"

"Curses, our plan is foiled!"

kilroy1232• 13 years ago

I'm glad I have no reason be that anonymous. Sounds stressful. :)

Still, I completely agree with you.

wglb2• 13 years ago

Have you tested this approach?

harshreality• 13 years ago

That isn't sufficient.

The NSA might be able to query their databases for anyone who recently visited the city where the wifi involved is located, and you might match that if there were license plate scanners on the way, even if you paid for gas in cash. If that information isn't collected by the NSA today, it probably will be tomorrow.

The NSA might be able to query their databases for anyone who "went off the grid" for a day or two around the event they're interested in. That's not good enough to id a suspect, but it narrows the pool. If you stopped making google searches from your normal internet connection within a day of the event in the other city, and you normally use your computer every day, or if your phone was off within a day of the event, that's suspicious. Enough of those kinds of data points and you become a suspect.

Even simpler, and a staple of crime fiction, stuff happens that you have no control over that can place you in the vicinity at the time of the event. If you have bad luck and get a ticket or get in a car accident in the city in question, for instance...

Far from suggesting that you simply need to be more careful, my view is that you can't take sufficient precautions to get risk down to a tolerable level if whatever you're doing brings you to the attention of the NSA.

ris2• 13 years ago

"Park a long distance from your wifi source where there are no cameras"

This implies that you've been driving round (in your disguise of course) in a car. With a registration plate.

chrisduesing• 13 years ago

Wait, so simply by using Tor the government will install malware on your computer. How is that legal?

boon2• 13 years ago

My interpretation of the article was that they identify prior to attacking.

I suppose they could use a "spray and pray" attack on anyone using Tor, but that would be easily detected.

shawn-furyan3• 13 years ago

One heartening aspect of the Snowden revelations as a whole is that they have pretty much just confirmed that the things we thought were strong (public crypto research, tor) are in fact strong and the things that we thought were iffy are in fact iffy(Certificate Authorities, Unvetted Crypto, Cloud Services, The Wires, Implementations). This bodes well for the prospect of navigating out of this whole mess successfully since on the whole we seem to have good instincts about what is trustworthy and what is untrustworthy. I think that it actually has tended to clarify thinking about security so that fewer and fewer engineers are able to delude themselves into trusting something that they know deep down is really untrustworthy.

anologwintermut3• 13 years ago

Prior to this one should not have (and arguably should sill not) assumed Tor is safe against the NSA.

Tor was explicitly not designed to protect against a global passive adversary. That's the price it pays for low latency. With the amount of network data the NSA has, they probably constitute such an adversary.

It is actually rather surprising that Tor gives them this much trouble.

jlgreco5• 13 years ago

It is actually rather surprising that Tor gives them this much trouble.

I am not really convinced that what we have seen demonstrates conclusively that it does. There is the possibility that we are looking at parallel construction, or that these attacks are genuine but they are sitting on more dramatic capabilities for targets they think are worth it (perhaps because the Chinese continuing to trust and use Tor is a better situation for the NSA to be in than the Chinese doing everything the old fashioned way with microfilm and dead-drops).

The best way to go forward is to continue to assume that Tor does not present any significant difficulty to the NSA.

shawn-furyan3• 13 years ago

It's a question of opportunity cost. The NSA has extensive resources, but it's unlikely that they can employ overwhelming resources (such as would be theoretically necessary to break tor) for every situation where overwhelming resources specifically directed are a theoretical weakness. At the moment, implementations are a much easier target, and so I don't necessarily think that it's surprising that they do have trouble with strong but imperfect systems like tor.

Perhaps once all implementation issues are removed from the security equation (I'll hold my breath while I wait...) it will be necessary to think up better systems. But right now, what's hard for us is hard for the NSA, and so that should be the guiding principle for strengthening current systems and developing new ones. I find that an empowering idea.

psn• 13 years ago

I agree with your post generally, but has Snowden said anything about CAs? I did expect to hear that at least one has signed anything the NSA put in front of them, but I don't recall Snowden providing "proof"* of this.

* I'm in no position to verify anything Snowden leaks.

shawn-furyan3• 13 years ago

The main thing is that CAs are centralized proxies for trust combined with the revelations that confirm that the NSA directly targets such central entities. There was a lot of general uneasiness about the reliance on CAs before the Snowden revelations, and I think the fact that NSA documents show that it leans on such central entities confirms the wisdom of that unease.

jerf• 13 years ago

We didn't need these revelations to know CAs are not generally trustworthy. We already had proof. http://en.wikipedia.org/wiki/Certificate_authority#CA_compro...

dsl3• 13 years ago

I don't know about the NSA, but I've personally negotiated a deal with a CA to add whatever domains we wanted to a certificate without validation. They just "trusted us."

return02• 13 years ago

The disheartening things is, though, we don't really have novel technologies (quantum crypto?) to guarantee security anymore and the existing ones will soon be exploitable on a mass scale. This is bad for internet commerce, and for internet itself as a medium. In the eyes of the layman, the internet is untrustworthy. I won't be surprised if in the future we will see closed, privately owned physical networks that guarantee security to their customers.

subdane• 13 years ago

I think Facebook proves definitively that the layman doesn't care about "trustworthiness of the internet".

tripzilch• 13 years ago

quantum crypto is going to be available to governments first and to civilians later, if at all, ever. we should be be making plans on how to protect ourselves from the cracking powers of quantum computers with our traditional computers instead: http://www.pqcrypto.org/

antocv2• 13 years ago

not to be a downer but I do feel these systems and exploits are designed by us the hackers we so much want to belive are good, but it looks like most hackers have a price and probably derive joy from designing these systems for the government.

we know what is trustworthy we know how to build and do the right thing. yet look there is tens of thousands of brilliant minds working for the nsa against everybody else.

guelo• 13 years ago

The weak point as usual are the endpoints. The attack vector described in these documents is JavaScript via some library called E4X. Makes me wonder why Tor bundle doesn't come with NoScript enabled by default.

steveklabnik2• 13 years ago

There is an answer about this in their FAQ that basically states that having NoScript on by default breaks too much of the web.

simgidacav• 13 years ago

Utopistically, how nice would be if the whole web provided no-javascript versions of the sites? In the end 90% of the cases javascript is used just to do fancy things, while actual functionalities could be achieved with much less pain (and vulnerability).

belorn2• 13 years ago

One iffy part I would like to add is government itself. It was generally thought that government would not keep security vulnerabilities hidden, prioritizing to protect citizens rather than having a minor advantage in hacking.

Together with the earlier leaks regarding sabotaged security standard, US government is the most damaging entity to computer security today. Anything they do need to be viewed under the understanding that NSA primary priority is to be able to hack other peoples computers. Be that a encryption algorithm, or a kernel module, NSA priority is 100% clear.

That used to be a tin-foil hat idea just a few months ago, and we know better now. If NSA comes carrying gifts, it warrant being very careful in accepting them from a party with such hostile priorities.

akjj2• 13 years ago

It was generally thought that government would not keep security vulnerabilities hidden

Was that what people thought? Were there vulnerability reports in open-source software that were coming from the NSA or thought to be coming from the NSA? Surely everyone knew that the NSA was capable of finding exploits in software, and I would think that it would be hard to keep secret whether or not they're being reported.

That used to be a tin-foil hat idea just a few months ago, and we know better now.

It's well-known that the NSA pushed to have DES limited to 56-bit keys. There were suspicions about Dual_EC_DRBG long before there were any leaks from Snowden. In the 90s, they pushed the Clipper chip, in which they'd engineered a back door. I think that everyone understood that the NSA had somewhat of an interest in weaker cryptography. That's why the cryptographic standardization processes happened in the open and when constants were needed, they were taken from the digits of pi or some such sequence.

mpyne7• 13 years ago

That used to be a tin-foil hat idea just a few months ago, and we know better now. If NSA comes carrying gifts, it warrant being very careful in accepting them from a party with such hostile priorities.

Well, not really.

The "tinfoil" idea is that NSA is breaking into crypto so that they can blackmail politicians, black-bag innocent citizens, etc.

But it was never widely assumed that NSA wasn't trying to break every bit of encryption they could. Besides the fact that such activities are literally their job, it's one of the few things they'd just as likely tell you directly if you asked them.

"Q: Are you trying to break cipher/cryptosystem FOO?" "A: Yes, we're trying to break all of them, to protect our SIGINT capability".

NSA has spent literally decades analyzing and breaking the military-grade ciphers of other nations. So I don't know where people got the idea that just because civilians obtained access to military-grade encryption, that NSA would suddenly stop with cryptanalysis efforts. But it has nothing to do with civilians per se; the military and national security opponents are using our civilian crypto too!

Is that inconvenient for civilian cryptography? Sure. But let's not act like people are having something chipped and taken away from them, that they've always had.

Before RSA and DH there was essentially no widely-known safe cryptosystems that we could use. You used DES, or you could make up your own Vigenère implementation perhaps (have fun with key exchange!).

And that's just discussing computer communications. Your phones were all tappable, international telegrams easily read if it suited NSA, and good luck if you used one of those new-fangled cell phones.

The claimed threat is that computers make NSA more capable of surveilling the people at large, but the evidence shows that systems like Tor are putting up an exceptional fight, and even cryptosystems like TLS with many known weaknesses mostly work against global passive surveillance.

You would have to get on NSA's specific shitlist to have to really worry, but being on that shitlist 20 years ago meant anything you said would be picked up... and now, even that is not so certain.

api• 13 years ago

I never thought that. I always assumed all cyber-war capable governments had hidden caches of 0-day vulnerabilities.

B-Con• 13 years ago

At a DefCon (15, I think?) I got to ask a panel of FBI/CIA/NSA bigwigs a question at an open Q/A panel. I asked how they made the decision of which exploits they'd keep for themselves and which they'd help the project patch.

The response was 100% boilerplate. "We have a system for evaluating it," was the basic answer, in more words than that. I didn't really expect anything more, but it was worth a shot.

I've never believed that their "system" was in any way primarily for the public interest. I can't point to any specific evidence, it just never felt like the type of thing they would do. Good exploits just seemed far too useful to be worth giving up.

pitchups• 13 years ago

It appears that the NSA has been able to target only Tor users that are using the Tor - Firefox bundle. So if you are using Chrome or some other browser - configured to use Tor, you would be safe from these exploits. Wouldn't most sophisticated hackers - or other high value targets most likely to be of interest to the NSA - be already doing that, rather than using the Firefox+Tor bundle?

andrewaylett2• 13 years ago

Unless you put a lot of effort into the integration, I'd advise against doing that -- the Firefox included in the bundle is specifically set up to avoid leaking information, while a standard Firefox or standard Chrome will phone home or do something else (like make a DNS request over the public network) that will quickly compromise any security you thought you had.

ksrm• 13 years ago

Can one use something like Lynx with Tor? I doubt there are very many exploits for it.

GigabyteCoin• 13 years ago

Is nobody slightly concerned that the date shown in the PDF file which sparked this commentary ( http://www.theguardian.com/world/interactive/2013/oct/04/tor... ) shows the PDF as being created in 2007?

It looks like they had some trouble picking out users 5 years ago... lord only knows how easy it must be for them now.

atmosx2• 13 years ago

I think this depends vastly on the number of rogue tor nodes. However, picture this: NSA isn't the only organization going after TOR right? Probably there are others.So if you are China, Iran, Syria, Russia, etc. What do you do? You set up your 'own' poisonous tor relays. What you end up doing is disrupting and diminishing the potential of a single agency or a group of agencies of controlling a big % of tor traffic.

So all in all, might be a good thing and way more difficult thatn it was 7 years earlier. Not to mention that at the time we were browsing through tor at 50 kb/s while now we browse at 400 kb/s.

welder• 13 years ago

The NSA is like Tor's pentesters, except Tor doesn't get to see the results.

dragonwriter• 13 years ago

Given that the US government is Tor's main funder, the first part may be more accurate than the second part.

frank_boyd• 13 years ago

I remember somebody from Mozilla thinking out loud "we should integrate Tor in Firefox". Glad that didn't get done.

andrewaylett2• 13 years ago

Why? Because it seems that Tor actually does what it says it does. One of the biggest issues with it is that using it singles you out; if we could get more people using it then it would be less useful as a differentiator.

g8oz• 13 years ago

I'm more glad that they didn't do it the other way around - considering how confident the NSA is about being able to keep finding new vulnerabilities in Firefox.

rdl• 13 years ago

Should really make a packaged vm in vm failsecure tbb equivalent. Nothing is really works from a usability standpoint while giving reasonable protections against this kind of endpoint attack.

doug1001• 13 years ago

don't forget that Tor publishes their exit nodes--they make them freely available to anyone. So a simple membership test on a client IP against that list of exit node IPs identifies that client IP as either having come through Tor via the onion router or else they are an exit node themselves.

jstalin• 13 years ago

So how does one determine which sites are being intercepted through Tor and served malformed code? Start doing CURLs from within Tor and outside of it and comparing hashes?

neves• 13 years ago

I've been playing with vagrant and ansible to create a new server in a snap. Here is a good weekend project:

Instead of having just an Tor/browser bundle, build a vagrant machine specification that installs the Tor bundle. This virtual machine would be destroyed and recreated from time to time. Now put the machine specification in GitHub and let anyone use it.

error54• 13 years ago

That's a great idea! Please let us know how that goes.

hawkharris• 13 years ago

Apparently, John Grisham works for the NSA, naming its programs.

gcb1• 13 years ago

what about the nonsense on the quantum system? i think the reporter left some key info out.

why does speed is a factor to mitm attacks? the slide shows a proper mintm diagram... or is this quatum thing exploiting a package arriving before the honest response? and why they would need to do that if they are in a position to do a proper mitm attack and not expose themselves for someone who monitors man-on-the-side attacks?

malandrew• 13 years ago

If someone makes disposable Raspberry Pi Tor exit and non-exit nodes sealed in hard plastic resin, we could all buy them and drop them off in random places throughout the world on open networks. If enough people the world over does this, we would make it a lot harder for a global passive attacker to succeed.

Tor's biggest vulnerability is the risk associated with operating exit nodes means that the number of exit nodes remains relatively low at ~1000 worldwide. If hundreds of thousands of exit nodes started popping up all over the globe. It would be very hard to counter.

I'm also curious if enough governments unhappy with what is happening could go as far as hosting many tor nodes outside the control of the NSA. Is the Global Passive Adversary threat still valid if there are many of them that are non-cooperative with one another (i.e. China can't monitor US and Russian tor nodes, Russia can't monitor US and Chinese nodes, and the US can't monitor Chinese and Russian nodes)? My intuition tells me that the global passive adversary would have to be able to monitor most of the nodes, but if others came on the scene doing the same, they would dilute the percentage of nodes that any single global passive adversary could monitor.

pygy_• 13 years ago

FoxAcid tags are designed to look innocuous, so that anyone who sees them would not be suspicious. An example of one such tag [LINK REMOVED] is given in another top-secret training presentation provided by Snowden.

Anyone knows what these tags look like?

espeed• 13 years ago

Foxacid sounds like an NSA version of BeEF (http://beefproject.com/), which hooks browsers that would then be monitored from the Lockheed-Martin-style SOC (https://www.youtube.com/watch?v=x1tCJfy_iZ4 :-).

However, for those with more limited resources, Ryan Barnett is working on an open-source monitoring system for BeEF (https://vimeo.com/54087884).

reirob• 13 years ago

In the slide titled "Exploitation: Shaping" the status says "Can stain user agents working on shaping."

How do they achieve to make tor use NSA/GCHQ nodes? If they achieved to do this 5 years ago (the PDF is from 2007) would it then be reasonable to assume that since then they have managed to modify the TOR source code in a way that nobody remarked to do exactly this?

Attacking Tor: How the NSA targets users' online anonymity

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