Entries Tagged "Edward Snowden"

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Why It's Important to Publish the NSA Programs

The Guardian recently reported on how the NSA targets Tor users, along with details of how it uses centrally placed servers on the Internet to attack individual computers. This builds on a Brazilian news story from a mid-September that, in part, shows that the NSA is impersonating Google servers to users; a German story on how the NSA is hacking into smartphones; and a Guardian story from early September on how the NSA is deliberately weakening common security algorithms, protocols, and products.

The common thread among these stories is that the NSA is subverting the Internet and turning it into a massive surveillance tool. The NSA’s actions are making us all less safe, because its eavesdropping mission is degrading its ability to protect the US.

Among IT security professionals, it has been long understood that the public disclosure of vulnerabilities is the only consistent way to improve security. That’s why researchers publish information about vulnerabilities in computer software and operating systems, cryptographic algorithms, and consumer products like implantable medical devices, cars, and CCTV cameras.

It wasn’t always like this. In the early years of computing, it was common for security researchers to quietly alert the product vendors about vulnerabilities, so they could fix them without the “bad guys” learning about them. The problem was that the vendors wouldn’t bother fixing them, or took years before getting around to it. Without public pressure, there was no rush.

This all changed when researchers started publishing. Now vendors are under intense public pressure to patch vulnerabilities as quickly as possible. The majority of security improvements in the hardware and software we all use today is a result of this process. This is why Microsoft’s Patch Tuesday process fixes so many vulnerabilities every month. This is why Apple’s iPhone is designed so securely. This is why so many products push out security updates so often. And this is why mass-market cryptography has continually improved. Without public disclosure, you’d be much less secure against cybercriminals, hacktivists, and state-sponsored cyberattackers.

The NSA’s actions turn that process on its head, which is why the security community is so incensed. The NSA not only develops and purchases vulnerabilities, but deliberately creates them through secret vendor agreements. These actions go against everything we know about improving security on the Internet.

It’s folly to believe that any NSA hacking technique will remain secret for very long. Yes, the NSA has a bigger research effort than any other institution, but there’s a lot of research being done—by other governments in secret, and in academic and hacker communities in the open. These same attacks are being used by other governments. And technology is fundamentally democratizing: today’s NSA secret techniques are tomorrow’s PhD theses and the following day’s cybercrime attack tools.

It’s equal folly to believe that the NSA’s secretly installed backdoors will remain secret. Given how inept the NSA was at protecting its own secrets, it’s extremely unlikely that Edward Snowden was the first sysadmin contractor to walk out the door with a boatload of them. And the previous leakers could have easily been working for a foreign government. But it wouldn’t take a rogue NSA employee; researchers or hackers could discover any of these backdoors on their own.

This isn’t hypothetical. We already know of government-mandated backdoors being used by criminals in Greece, Italy, and elsewhere. We know China is actively engaging in cyber-espionage worldwide. A recent Economist article called it “akin to a government secretly commanding lockmakers to make their products easier to pick—and to do so amid an epidemic of burglary.”

The NSA has two conflicting missions. Its eavesdropping mission has been getting all the headlines, but it also has a mission to protect US military and critical infrastructure communications from foreign attack. Historically, these two missions have not come into conflict. During the cold war, for example, we would defend our systems and attack Soviet systems.

But with the rise of mass-market computing and the Internet, the two missions have become interwoven. It becomes increasingly difficult to attack their systems and defend our systems, because everything is using the same systems: Microsoft Windows, Cisco routers, HTML, TCP/IP, iPhones, Intel chips, and so on. Finding a vulnerability—or creating one—and keeping it secret to attack the bad guys necessarily leaves the good guys more vulnerable.

Far better would be for the NSA to take those vulnerabilities back to the vendors to patch. Yes, it would make it harder to eavesdrop on the bad guys, but it would make everyone on the Internet safer. If we believe in protecting our critical infrastructure from foreign attack, if we believe in protecting Internet users from repressive regimes worldwide, and if we believe in defending businesses and ourselves from cybercrime, then doing otherwise is lunacy.

It is important that we make the NSA’s actions public in sufficient detail for the vulnerabilities to be fixed. It’s the only way to force change and improve security.

This essay previously appeared in the Guardian.

Posted on October 8, 2013 at 6:44 AMView Comments

How the NSA Attacks Tor/Firefox Users With QUANTUM and FOXACID

The online anonymity network Tor is a high-priority target for the National Security Agency. The work of attacking Tor is done by the NSA‘s application vulnerabilities branch, which is part of the systems intelligence directorate, or SID. The majority of NSA employees work in SID, which is tasked with collecting data from communications systems around the world.

According to a top-secret NSA presentation provided by the whistleblower Edward Snowden, one successful technique the NSA has developed involves exploiting the Tor browser bundle, a collection of programs designed to make it easy for people to install and use the software. The trick identifies Tor users on the Internet and then executes an attack against their Firefox web browser.

The NSA refers to these capabilities as CNE, or computer network exploitation.

The first step of this process is finding Tor users. To accomplish this, the NSA relies on its vast capability to monitor large parts of the Internet. This is done via the agency’s partnership with US telecoms firms under programs codenamed Stormbrew, Fairview, Oakstar and Blarney.

The NSA creates “fingerprints” that detect HTTP requests from the Tor network to particular servers. These fingerprints are loaded into NSA database systems like XKeyscore, a bespoke collection and analysis tool that NSA boasts allows its analysts to see “almost everything” a target does on the Internet.

Using powerful data analysis tools with codenames such as Turbulence, Turmoil and Tumult, the NSA automatically sifts through the enormous amount of Internet traffic that it sees, looking for Tor connections.

Last month, Brazilian TV news show Fantastico showed screenshots of an NSA tool that had the ability to identify Tor users by monitoring Internet traffic.

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. 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.

After identifying an individual Tor user on the Internet, the NSA uses its network of secret Internet servers to redirect those users to another set of secret Internet servers, with the codename FoxAcid, to infect the user’s computer. FoxAcid is an NSA system designed to act as a matchmaker between potential targets and attacks developed by the NSA, giving the agency opportunity to launch prepared attacks against their systems.

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, and continues to provide eavesdropping information back to the NSA.

Exploiting the Tor browser bundle

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.

This, too, is difficult. Tor users often turn off vulnerable services like scripts and Flash when using Tor, making it difficult to target those services. Even so, the NSA uses a series of native Firefox vulnerabilities to attack users of the Tor browser bundle.

According to the training presentation provided by Snowden, EgotisticalGiraffe exploits a type confusion vulnerability in E4X, which is an XML extension for JavaScript. This vulnerability exists in Firefox 11.0—16.0.2, as well as Firefox 10.0 ESR—the Firefox version used until recently in the Tor browser bundle. According to another document, the vulnerability exploited by EgotisticalGiraffe was inadvertently fixed when Mozilla removed the E4X library with the vulnerability, and when Tor added that Firefox version into the Tor browser bundle, but NSA were confident that they would be able to find a replacement Firefox exploit that worked against version 17.0 ESR.

The Quantum system

To trick targets into visiting a FoxAcid server, the NSA relies on its secret partnerships with US telecoms companies. As part of the Turmoil system, the NSA places secret servers, codenamed Quantum, at key places on the Internet backbone. This placement ensures that they can react faster than other websites can. By exploiting that speed difference, these servers can impersonate a visited website to the target before the legitimate website can respond, thereby tricking the target’s browser to visit a Foxacid server.

In the academic literature, these are called “man-in-the-middle” attacks, and have been known to the commercial and academic security communities. More specifically, they are examples of “man-on-the-side” attacks.

They are hard for any organization other than the NSA to reliably execute, because they require the attacker to have a privileged position on the Internet backbone, and exploit a “race condition” between the NSA server and the legitimate website. This top-secret NSA diagram, made public last month, shows a Quantum server impersonating Google in this type of attack.

The NSA uses these fast Quantum servers to execute a packet injection attack, which surreptitiously redirects the target to the FoxAcid server. An article in the German magazine Spiegel, based on additional top secret Snowden documents, mentions an NSA developed attack technology with the name of QuantumInsert that performs redirection attacks. Another top-secret Tor presentation provided by Snowden mentions QuantumCookie to force cookies onto target browsers, and another Quantum program to “degrade/deny/disrupt Tor access”.

This same technique is used by the Chinese government to block its citizens from reading censored Internet content, and has been hypothesized as a probable NSA attack technique.

The FoxAcid system

According to various top-secret documents provided by Snowden, FoxAcid is the NSA codename for what the NSA calls an “exploit orchestrator,” an Internet-enabled system capable of attacking target computers in a variety of different ways. It is a Windows 2003 computer configured with custom software and a series of Perl scripts. These servers are run by the NSA’s tailored access operations, or TAO, group. TAO is another subgroup of the systems intelligence directorate.

The servers are on the public Internet. They have normal-looking domain names, and can be visited by any browser from anywhere; ownership of those domains cannot be traced back to the NSA.

However, if a browser tries to visit a FoxAcid server with a special URL, called a FoxAcid tag, the server attempts to infect that browser, and then the computer, in an effort to take control of it. The NSA can trick browsers into using that URL using a variety of methods, including the race-condition attack mentioned above and frame injection attacks.

FoxAcid tags are designed to look innocuous, so that anyone who sees them would not be suspicious. http://baseball2.2ndhalfplays.com/nested/attribs/bins/1/define/forms9952_z1zzz.html is an example of one such tag, given in another top-secret training presentation provided by Snowden.

There is no currently registered domain name by that name; it is just an example for internal NSA training purposes.

The training material states that merely trying to visit the homepage of a real FoxAcid server will not result in any attack, and that a specialized URL is required. This URL would be created by TAO for a specific NSA operation, and unique to that operation and target. This allows the FoxAcid server to know exactly who the target is when his computer contacts it.

According to Snowden, FoxAcid is a general CNE system, used for many types of attacks other than the Tor attacks described here. It is designed to be modular, with flexibility that allows TAO to swap and replace exploits if they are discovered, and only run certain exploits against certain types of targets.

The most valuable exploits are saved for the most important targets. Low-value exploits are run against technically sophisticated targets where the chance of detection is high. TAO maintains a library of exploits, each based on a different vulnerability in a system. Different exploits are authorized against different targets, depending on the value of the target, the target’s technical sophistication, the value of the exploit, and other considerations.

In the case of Tor users, FoxAcid might use EgotisticalGiraffe against their Firefox browsers.

According to a top-secret operational management procedures manual provided by Snowden, once a target is successfully exploited it is infected with one of several payloads. Two basic payloads mentioned in the manual are designed to collect configuration and location information from the target computer so an analyst can determine how to further infect the computer.

These decisions are made in part by the technical sophistication of the target and the security software installed on the target computer, called Personal Security Products or PSP, in the manual.

FoxAcid payloads are updated regularly by TAO. For example, the manual refers to version 8.2.1.1 of one of them.

FoxAcid servers also have sophisticated capabilities to avoid detection and to ensure successful infection of its targets. The operations manual states that a FoxAcid payload with the codename DireScallop can circumvent commercial products that prevent malicious software from making changes to a system that survive a reboot process.

The NSA also uses phishing attacks to induce users to click on FoxAcid tags.

TAO additionally uses FoxAcid to exploit callbacks—which is the general term for a computer infected by some automatic means—calling back to the NSA for more instructions and possibly to upload data from the target computer.

According to a top-secret operational management procedures manual, FoxAcid servers configured to receive callbacks are codenamed FrugalShot. After a callback, the FoxAcid server may run more exploits to ensure that the target computer remains compromised long term, as well as install “implants” designed to exfiltrate data.

By 2008, the NSA was getting so much FoxAcid callback data that they needed to build a special system to manage it all.

This essay previously appeared in the Guardian. It is the technical article associated with this more general-interest article. I also wrote two commentaries on the material.

EDITED TO ADD: Here is the source material we published. The Washington Post published its own story independently, based on some of the same source material and some new source material.

Here’s the official US government response to the story.

The Guardian decided to change the capitalization of the NSA codenames. They should properly be in all caps: FOXACID, QUANTUMCOOKIE, EGOTISTICALGIRAFFE, TURMOIL, and so on.

This is the relevant quote from the Spiegel article:

According to the slides in the GCHQ presentation, the attack was directed at several Belgacom employees and involved the planting of a highly developed attack technology referred to as a “Quantum Insert” (“QI”). It appears to be a method with which the person being targeted, without their knowledge, is redirected to websites that then plant malware on their computers that can then manipulate them. Some of the employees whose computers were infiltrated had “good access” to important parts of Belgacom’s infrastructure, and this seemed to please the British spies, according to the slides.

That should be “QUANTUMINSERT.” This is getting frustrating. The NSA really should release a style guide for press organizations publishing their secrets.

And the URL in the essay (now redacted at the Guardian site) was registered within minutes of the story posting, and is being used to serve malware. Don’t click on it.

Posted on October 7, 2013 at 6:24 AMView Comments

NSA Storing Internet Data, Social Networking Data, on Pretty Much Everybody

Two new stories based on the Snowden documents.

This is getting silly. General Alexander just lied about this to Congress last week. The old NSA tactic of hiding behind a shell game of different code names is failing. It used to be they could get away with saying “Project X doesn’t do that,” knowing full well that Projects Y and Z did and that no one would call them on it. Now they’re just looking shiftier and shiftier.

The program the New York Times exposed is basically Total Information Awareness, which Congress defunded in 2003 because it was just too damned creepy. Now it’s back. (Actually, it never really went away. It just changed code names.)

I’m also curious how all those PRISM-era denials from Internet companies about the NSA not having “direct access” to their servers jibes with this paragraph:

The overall volume of metadata collected by the N.S.A. is reflected in the agency’s secret 2013 budget request to Congress. The budget document, disclosed by Mr. Snowden, shows that the agency is pouring money and manpower into creating a metadata repository capable of taking in 20 billion “record events” daily and making them available to N.S.A. analysts within 60 minutes.

Honestly, I think the details matter less and less. We have to assume that the NSA has everyone who uses electronic communications under constant surveillance. New details about hows and whys will continue to emerge—for example, now we know the NSA’s repository contains travel data—but the big picture will remain the same.

Related: I’ve said that it seems that the NSA now has a PR firm advising it on response. It’s trying to teach General Alexander how to better respond to questioning.

Also related: A cute flowchart on how to avoid NSA surveillance.

Posted on October 1, 2013 at 1:08 PMView Comments

Will Keccak = SHA-3?

Last year, NIST selected Keccak as the winner of the SHA-3 hash function competition. Yes, I would have rather my own Skein had won, but it was a good choice.

But last August, John Kelsey announced some changes to Keccak in a talk (slides 44-48 are relevant). Basically, the security levels were reduced and some internal changes to the algorithm were made, all in the name of software performance.

Normally, this wouldn’t be a big deal. But in light of the Snowden documents that reveal that the NSA has attempted to intentionally weaken cryptographic standards, this is a huge deal. There is too much mistrust in the air. NIST risks publishing an algorithm that no one will trust and no one (except those forced) will use.

At this point, they simply have to standardize on Keccak as submitted and as selected.

CDT has a great post about this.

Also this Slashdot thread.

EDITED TO ADD (10/5): It’s worth reading the response from the Keccak team on this issue.

I misspoke when I wrote that NIST made “internal changes” to the algorithm. That was sloppy of me. The Keccak permutation remains unchanged. What NIST proposed was reducing the hash function’s capacity in the name of performance. One of Keccak’s nice features is that it’s highly tunable.

I do not believe that the NIST changes were suggested by the NSA. Nor do I believe that the changes make the algorithm easier to break by the NSA. I believe NIST made the changes in good faith, and the result is a better security/performance trade-off. My problem with the changes isn’t cryptographic, it’s perceptual. There is so little trust in the NSA right now, and that mistrust is reflecting on NIST. I worry that the changed algorithm won’t be accepted by an understandably skeptical security community, and that no one will use SHA-3 as a result.

This is a lousy outcome. NIST has done a great job with cryptographic competitions: both a decade ago with AES and now with SHA-3. This is just another effect of the NSA’s actions draining the trust out of the Internet.

Posted on October 1, 2013 at 10:50 AMView Comments

Senator Feinstein Admits the NSA Taps the Internet Backbone

We know from the Snowden documents (and other sources) that the NSA taps the Internet backbone through secret agreements with major US telcos., but the US government still hasn’t admitted it.

In late August, the Obama administration declassified a ruling from the Foreign Intelligence Surveillance Court. Footnote 3 reads:

The term ‘upstream collection’ refers to NSA’s interception of Internet communications as they transit [LONG REDACTED CLAUSE], [REDACTED], rather than to acquisitions directly from Internet service providers such as [LIST OF REDACTED THINGS, PRESUMABLY THE PRISM DOWNSTREAM COMPANIES].

Here’s one analysis of the document.

On Thursday, Senator Diane Feinstein filled in some of the details:

Upstream collection…occurs when NSA obtains internet communications, such as e-mails, from certain US companies that operate the Internet background [sic, she means “backbone”], i.e., the companies that own and operate the domestic telecommunications lines over which internet traffic flows.

Note that we knew this in 2006:

One thing the NSA wanted was access to the growing fraction of global telecommunications that passed through junctions on U.S. territory. According to former senator Bob Graham (D-Fla.), who chaired the Intelligence Committee at the time, briefers told him in Cheney’s office in October 2002 that Bush had authorized the agency to tap into those junctions. That decision, Graham said in an interview first reported in The Washington Post on Dec. 18, allowed the NSA to intercept “conversations that . . . went through a transit facility inside the United States.”

And this in 2007:

[The Program] requires the NSA, as noted by Rep. Peter Hoekstra, “to steal light off of different cables” in order to acquire the “information that’s most important to us” Interview with Rep. Peter Hoekstra by Paul Gigot, Lack of Intelligence: Congress Dawdles on Terrorist Wiretapping, JOURNAL EDITORIAL REPORT, FOX NEWS CHANNEL (Aug. 6, 2007) at 2.

So we knew it already, but now we know it even more. So why won’t President Obama admit it?

EDITED TO ADD (9/28): Another article on this.

EDITED TO ADD (9/30): Also, there’s Mark Klein’s revelations from 2006.

Posted on September 28, 2013 at 6:10 AMView Comments

Metadata Equals Surveillance

Back in June, when the contents of Edward Snowden’s cache of NSA documents were just starting to be revealed and we learned about the NSA collecting phone metadata of every American, many people—including President Obama—discounted the seriousness of the NSA’s actions by saying that it’s just metadata.

Lots and lots of people effectively demolished that trivialization, but the arguments are generally subtle and hard to convey quickly and simply. I have a more compact argument: metadata equals surveillance.

Imagine you hired a detective to eavesdrop on someone. He might plant a bug in their office. He might tap their phone. He might open their mail. The result would be the details of that person’s communications. That’s the “data.”

Now imagine you hired that same detective to surveil that person. The result would be details of what he did: where he went, who he talked to, what he looked at, what he purchased—how he spent his day. That’s all metadata.

When the government collects metadata on people, the government puts them under surveillance. When the government collects metadata on the entire country, they put everyone under surveillance. When Google does it, they do the same thing. Metadata equals surveillance; it’s that simple.

EDITED TO ADD (10/12): According to Snowden, the administration is partially basing its bulk collection of metadata on an interpretation by the FISC of Section 215 of the Patriot Act.

EDITED TO ADD (10/28): this post has been translated into Portuguese.

Posted on September 23, 2013 at 6:21 AMView Comments

Reforming the NSA

Leaks from the whistleblower Edward Snowden have catapulted the NSA into newspaper headlines and demonstrated that it has become one of the most powerful government agencies in the country. From the secret court rulings that allow it to collect data on all Americans to its systematic subversion of the entire Internet as a surveillance platform, the NSA has amassed an enormous amount of power.

There are two basic schools of thought about how this came to pass. The first focuses on the agency’s power. Like J. Edgar Hoover, NSA Director Keith Alexander has become so powerful as to be above the law. He is able to get away with what he does because neither political party—and nowhere near enough individual lawmakers—dare cross him. Longtime NSA watcher James Bamford recently quoted a CIA official: “We jokingly referred to him as Emperor Alexander—with good cause, because whatever Keith wants, Keith gets.”

Possibly the best evidence for this position is how well Alexander has weathered the Snowden leaks. The NSA’s most intimate secrets are front-page headlines, week after week. Morale at the agency is in shambles. Revelation after revelation has demonstrated that Alexander has exceeded his authority, deceived Congress, and possibly broken the law. Tens of thousands of additional top-secret documents are still waiting to come. Alexander has admitted that he still doesn’t know what Snowden took with him and wouldn’t have known about the leak at all had Snowden not gone public. He has no idea who else might have stolen secrets before Snowden, or who such insiders might have provided them to. Alexander had no contingency plans in place to deal with this sort of security breach, and even now—four months after Snowden fled the country—still has no coherent response to all this.

For an organization that prides itself on secrecy and security, this is what failure looks like. It is a testament to Alexander’s power that he still has a job.

The second school of thought is that it’s the administration’s fault—not just the present one, but the most recent several. According to this theory, the NSA is simply doing its job. If there’s a problem with the NSA’s actions, it’s because the rules it’s operating under are bad. Like the military, the NSA is merely an instrument of national policy. Blaming the NSA for creating a surveillance state is comparable to blaming the US military for the conduct of the Iraq war. Alexander is performing the mission given to him as best he can, under the rules he has been given, with the sort of zeal you’d expect from someone promoted into that position. And the NSA’s power predated his directorship.

Former NSA Director Michael Hayden exemplifies this in a quote from late July: “Give me the box you will allow me to operate in. I’m going to play to the very edges of that box.”

This doesn’t necessarily mean the administration is deliberately giving the NSA too big a box. More likely, it’s simply that the laws aren’t keeping pace with technology. Every year, technology gives us possibilities that our laws simply don’t cover clearly. And whenever there’s a gray area, the NSA interprets whatever law there is to give them the most expansive authority. They simply run rings around the secret court that rules on these things. My guess is that while they have clearly broken the spirit of the law, it’ll be harder to demonstrate that they broke the letter of the law.

In football terms, the first school of thought says the NSA is out of bounds. The second says the field is too big. I believe that both perspectives have some truth to them, and that the real problem comes from their combination.

Regardless of how we got here, the NSA can’t reform itself. Change cannot come from within; it has to come from above. It’s the job of government: of Congress, of the courts, and of the president. These are the people who have the ability to investigate how things became so bad, rein in the rogue agency, and establish new systems of transparency, oversight, and accountability.

Any solution we devise will make the NSA less efficient at its eavesdropping job. That’s a trade-off we should be willing to make, just as we accept reduced police efficiency caused by requiring warrants for searches and warning suspects that they have the right to an attorney before answering police questions. We do this because we realize that a too-powerful police force is itself a danger, and we need to balance our need for public safety with our aversion of a police state.

The same reasoning needs to apply to the NSA. We want it to eavesdrop on our enemies, but it needs to do so in a way that doesn’t trample on the constitutional rights of Americans, or fundamentally jeopardize their privacy or security. This means that sometimes the NSA won’t get to eavesdrop, just as the protections we put in place to restrain police sometimes result in a criminal getting away. This is a trade-off we need to make willingly and openly, because overall we are safer that way.

Once we do this, there needs to be a cultural change within the NSA. Like at the FBI and CIA after past abuses, the NSA needs new leadership committed to changing its culture. And giving up power.

Our society can handle the occasional terrorist act; we’re resilient, and—if we decided to act that way—indomitable. But a government agency that is above the law… it’s hard to see how America and its freedoms can survive that.

This essay previously appeared on TheAtlantic.com, with the unfortunate title of “Zero Sum: Americans Must Sacrifice Some Security to Reform the NSA.” After I complained, they changed the title to “The NSA-Reform Paradox: Stop Domestic Spying, Get More Security.”

Posted on September 16, 2013 at 6:55 AMView Comments

Take Back the Internet

Government and industry have betrayed the Internet, and us.

By subverting the Internet at every level to make it a vast, multi-layered and robust surveillance platform, the NSA has undermined a fundamental social contract. The companies that build and manage our Internet infrastructure, the companies that create and sell us our hardware and software, or the companies that host our data: we can no longer trust them to be ethical Internet stewards.

This is not the Internet the world needs, or the Internet its creators envisioned. We need to take it back.

And by we, I mean the engineering community.

Yes, this is primarily a political problem, a policy matter that requires political intervention.

But this is also an engineering problem, and there are several things engineers can—and should—do.

One, we should expose. If you do not have a security clearance, and if you have not received a National Security Letter, you are not bound by a federal confidentially requirements or a gag order. If you have been contacted by the NSA to subvert a product or protocol, you need to come forward with your story. Your employer obligations don’t cover illegal or unethical activity. If you work with classified data and are truly brave, expose what you know. We need whistleblowers.

We need to know how exactly how the NSA and other agencies are subverting routers, switches, the Internet backbone, encryption technologies and cloud systems. I already have five stories from people like you, and I’ve just started collecting. I want 50. There’s safety in numbers, and this form of civil disobedience is the moral thing to do.

Two, we can design. We need to figure out how to re-engineer the Internet to prevent this kind of wholesale spying. We need new techniques to prevent communications intermediaries from leaking private information.

We can make surveillance expensive again. In particular, we need open protocols, open implementations, open systems—these will be harder for the NSA to subvert.

The Internet Engineering Task Force, the group that defines the standards that make the internet run, has a meeting planned for early November in Vancouver. This group needs to dedicate its next meeting to this task. This is an emergency, and demands an emergency response.

Three, we can influence governance. I have resisted saying this up to now, and I am saddened to say it, but the US has proved to be an unethical steward of the Internet. The UK is no better. The NSA’s actions are legitimizing the internet abuses by China, Russia, Iran and others. We need to figure out new means of internet governance, ones that makes it harder for powerful tech countries to monitor everything. For example, we need to demand transparency, oversight, and accountability from our governments and corporations.

Unfortunately, this is going play directly into the hands of totalitarian governments that want to control their country’s Internet for even more extreme forms of surveillance. We need to figure out how to prevent that, too. We need to avoid the mistakes of the International Telecommunications Union, which has become a forum to legitimize bad government behavior, and create truly international governance that can’t be dominated or abused by any one country.

Generations from now, when people look back on these early decades of the Internet, I hope they will not be disappointed in us. We can ensure that they don’t only if each of us makes this a priority, and engages in the debate. We have a moral duty to do this, and we have no time to lose.

Dismantling the surveillance state won’t be easy. Has any country that engaged in mass surveillance of its own citizens voluntarily given up that capability? Has any mass surveillance country avoided becoming totalitarian? Whatever happens, we’re going to be breaking new ground.

Again, the politics of this is a bigger task than the engineering, but the engineering is critical. We need to demand that real technologists be involved in any key government decision making on these issues. We’ve had enough of lawyers and politicians not fully understanding technology; we need technologists at the table when we build tech policy.

To the engineers, I say this: we built the Internet, and some of us have helped to subvert it. Now, those of us who love liberty have to fix it.

This essay previously appeared in the Guardian.

EDITED TO ADD: Slashdot thread. An opposing view to my call to action. And I agree with this, even though the author presents this as an opposing view to mine.

EDITED TO ADD: This essay has been translated into German.

Posted on September 15, 2013 at 11:53 AMView Comments

How to Remain Secure Against the NSA

Now that we have enough details about how the NSA eavesdrops on the Internet, including today’s disclosures of the NSA’s deliberate weakening of cryptographic systems, we can finally start to figure out how to protect ourselves.

For the past two weeks, I have been working with the Guardian on NSA stories, and have read hundreds of top-secret NSA documents provided by whistleblower Edward Snowden. I wasn’t part of today’s story—it was in process well before I showed up—but everything I read confirms what the Guardian is reporting.

At this point, I feel I can provide some advice for keeping secure against such an adversary.

The primary way the NSA eavesdrops on Internet communications is in the network. That’s where their capabilities best scale. They have invested in enormous programs to automatically collect and analyze network traffic. Anything that requires them to attack individual endpoint computers is significantly more costly and risky for them, and they will do those things carefully and sparingly.

Leveraging its secret agreements with telecommunications companies—all the US and UK ones, and many other “partners” around the world—the NSA gets access to the communications trunks that move Internet traffic. In cases where it doesn’t have that sort of friendly access, it does its best to surreptitiously monitor communications channels: tapping undersea cables, intercepting satellite communications, and so on.

That’s an enormous amount of data, and the NSA has equivalently enormous capabilities to quickly sift through it all, looking for interesting traffic. “Interesting” can be defined in many ways: by the source, the destination, the content, the individuals involved, and so on. This data is funneled into the vast NSA system for future analysis.

The NSA collects much more metadata about Internet traffic: who is talking to whom, when, how much, and by what mode of communication. Metadata is a lot easier to store and analyze than content. It can be extremely personal to the individual, and is enormously valuable intelligence.

The Systems Intelligence Directorate is in charge of data collection, and the resources it devotes to this is staggering. I read status report after status report about these programs, discussing capabilities, operational details, planned upgrades, and so on. Each individual problem—recovering electronic signals from fiber, keeping up with the terabyte streams as they go by, filtering out the interesting stuff—has its own group dedicated to solving it. Its reach is global.

The NSA also attacks network devices directly: routers, switches, firewalls, etc. Most of these devices have surveillance capabilities already built in; the trick is to surreptitiously turn them on. This is an especially fruitful avenue of attack; routers are updated less frequently, tend not to have security software installed on them, and are generally ignored as a vulnerability.

The NSA also devotes considerable resources to attacking endpoint computers. This kind of thing is done by its TAO—Tailored Access Operations—group. TAO has a menu of exploits it can serve up against your computer—whether you’re running Windows, Mac OS, Linux, iOS, or something else—and a variety of tricks to get them on to your computer. Your anti-virus software won’t detect them, and you’d have trouble finding them even if you knew where to look. These are hacker tools designed by hackers with an essentially unlimited budget. What I took away from reading the Snowden documents was that if the NSA wants in to your computer, it’s in. Period.

The NSA deals with any encrypted data it encounters more by subverting the underlying cryptography than by leveraging any secret mathematical breakthroughs. First, there’s a lot of bad cryptography out there. If it finds an Internet connection protected by MS-CHAP, for example, that’s easy to break and recover the key. It exploits poorly chosen user passwords, using the same dictionary attacks hackers use in the unclassified world.

As was revealed today, the NSA also works with security product vendors to ensure that commercial encryption products are broken in secret ways that only it knows about. We know this has happened historically: CryptoAG and Lotus Notes are the most public examples, and there is evidence of a back door in Windows. A few people have told me some recent stories about their experiences, and I plan to write about them soon. Basically, the NSA asks companies to subtly change their products in undetectable ways: making the random number generator less random, leaking the key somehow, adding a common exponent to a public-key exchange protocol, and so on. If the back door is discovered, it’s explained away as a mistake. And as we now know, the NSA has enjoyed enormous success from this program.

TAO also hacks into computers to recover long-term keys. So if you’re running a VPN that uses a complex shared secret to protect your data and the NSA decides it cares, it might try to steal that secret. This kind of thing is only done against high-value targets.

How do you communicate securely against such an adversary? Snowden said it in an online Q&A soon after he made his first document public: “Encryption works. Properly implemented strong crypto systems are one of the few things that you can rely on.”

I believe this is true, despite today’s revelations and tantalizing hints of “groundbreaking cryptanalytic capabilities” made by James Clapper, the director of national intelligence in another top-secret document. Those capabilities involve deliberately weakening the cryptography.

Snowden’s follow-on sentence is equally important: “Unfortunately, endpoint security is so terrifically weak that NSA can frequently find ways around it.”

Endpoint means the software you’re using, the computer you’re using it on, and the local network you’re using it in. If the NSA can modify the encryption algorithm or drop a Trojan on your computer, all the cryptography in the world doesn’t matter at all. If you want to remain secure against the NSA, you need to do your best to ensure that the encryption can operate unimpeded.

With all this in mind, I have five pieces of advice:

  1. Hide in the network. Implement hidden services. Use Tor to anonymize yourself. Yes, the NSA targets Tor users, but it’s work for them. The less obvious you are, the safer you are.
  2. Encrypt your communications. Use TLS. Use IPsec. Again, while it’s true that the NSA targets encrypted connections—and it may have explicit exploits against these protocols—you’re much better protected than if you communicate in the clear.
  3. Assume that while your computer can be compromised, it would take work and risk on the part of the NSA—so it probably isn’t. If you have something really important, use an air gap. Since I started working with the Snowden documents, I bought a new computer that has never been connected to the Internet. If I want to transfer a file, I encrypt the file on the secure computer and walk it over to my Internet computer, using a USB stick. To decrypt something, I reverse the process. This might not be bulletproof, but it’s pretty good.
  4. Be suspicious of commercial encryption software, especially from large vendors. My guess is that most encryption products from large US companies have NSA-friendly back doors, and many foreign ones probably do as well. It’s prudent to assume that foreign products also have foreign-installed backdoors. Closed-source software is easier for the NSA to backdoor than open-source software. Systems relying on master secrets are vulnerable to the NSA, through either legal or more clandestine means.
  5. Try to use public-domain encryption that has to be compatible with other implementations. For example, it’s harder for the NSA to backdoor TLS than BitLocker, because any vendor’s TLS has to be compatible with every other vendor’s TLS, while BitLocker only has to be compatible with itself, giving the NSA a lot more freedom to make changes. And because BitLocker is proprietary, it’s far less likely those changes will be discovered. Prefer symmetric cryptography over public-key cryptography. Prefer conventional discrete-log-based systems over elliptic-curve systems; the latter have constants that the NSA influences when they can.

Since I started working with Snowden’s documents, I have been using GPG, Silent Circle, Tails, OTR, TrueCrypt, BleachBit, and a few other things I’m not going to write about. There’s an undocumented encryption feature in my Password Safe program from the command line; I’ve been using that as well.

I understand that most of this is impossible for the typical Internet user. Even I don’t use all these tools for most everything I am working on. And I’m still primarily on Windows, unfortunately. Linux would be safer.

The NSA has turned the fabric of the Internet into a vast surveillance platform, but they are not magical. They’re limited by the same economic realities as the rest of us, and our best defense is to make surveillance of us as expensive as possible.

Trust the math. Encryption is your friend. Use it well, and do your best to ensure that nothing can compromise it. That’s how you can remain secure even in the face of the NSA.

This essay previously appeared in the Guardian.

EDITED TO ADD: Reddit thread.

Someone somewhere commented that the NSA’s “groundbreaking cryptanalytic capabilities” could include a practical attack on RC4. I don’t know one way or the other, but that’s a good speculation.

Posted on September 15, 2013 at 8:11 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.