The Benefits of Endpoint Encryption
An unofficial blog post from FTC chief technologist Ashkan Soltani on the virtues of strong end-user device controls.
Entries Tagged "encryption"
Page 26 of 56
NSA Plans for a Post-Quantum World
Quantum computing is a novel way to build computers—one that takes advantage of the quantum properties of particles to perform operations on data in a very different way than traditional computers. In some cases, the algorithm speedups are extraordinary.
Specifically, a quantum computer using something called Shor’s algorithm can efficiently factor numbers, breaking RSA. A variant can break Diffie-Hellman and other discrete log-based cryptosystems, including those that use elliptic curves. This could potentially render all modern public-key algorithms insecure. Before you panic, note that the largest number to date that has been factored by a quantum computer is 143. So while a practical quantum computer is still science fiction, it’s not stupid science fiction.
(Note that this is completely different from quantum cryptography, which is a way of passing bits between two parties that relies on physical quantum properties for security. The only thing quantum computation and quantum cryptography have to do with each other is their first words. It is also completely different from the NSA’s QUANTUM program, which is its code name for a packet-injection system that works directly in the Internet backbone.)
Practical quantum computation doesn’t mean the end of cryptography. There are lesser-known public-key algorithms such as McEliece and lattice-based algorithms that, while less efficient than the ones we use, are currently secure against a quantum computer. And quantum computation only speeds up a brute-force keysearch by a factor of a square root, so any symmetric algorithm can be made secure against a quantum computer by doubling the key length.
We know from the Snowden documents that the NSA is conducting research on both quantum computation and quantum cryptography. It’s not a lot of money, and few believe that the NSA has made any real advances in theoretical or applied physics in this area. My guess has been that we’ll see a practical quantum computer within 30 to 40 years, but not much sooner than that.
This all means that now is the time to think about what living in a post-quantum world would be like. NIST is doing its part, having hosted a conference on the topic earlier this year. And the NSA announced that it is moving towards quantum-resistant algorithms.
Earlier this week, the NSA’s Information Assurance Directorate updated its list of Suite B cryptographic algorithms. It explicitly talked about the threat of quantum computers:
IAD will initiate a transition to quantum resistant algorithms in the not too distant future. Based on experience in deploying Suite B, we have determined to start planning and communicating early about the upcoming transition to quantum resistant algorithms. Our ultimate goal is to provide cost effective security against a potential quantum computer. We are working with partners across the USG, vendors, and standards bodies to ensure there is a clear plan for getting a new suite of algorithms that are developed in an open and transparent manner that will form the foundation of our next Suite of cryptographic algorithms.
Until this new suite is developed and products are available implementing the quantum resistant suite, we will rely on current algorithms. For those partners and vendors that have not yet made the transition to Suite B elliptic curve algorithms, we recommend not making a significant expenditure to do so at this point but instead to prepare for the upcoming quantum resistant algorithm transition.
Suite B is a family of cryptographic algorithms approved by the NSA. It’s all part of the NSA’s Cryptographic Modernization Program. Traditionally, NSA algorithms were classified and could only be used in specially built hardware modules. Suite B algorithms are public, and can be used in anything. This is not to say that Suite B algorithms are second class, or breakable by the NSA. They’re being used to protect US secrets: “Suite A will be used in applications where Suite B may not be appropriate. Both Suite A and Suite B can be used to protect foreign releasable information, US-Only information, and Sensitive Compartmented Information (SCI).”
The NSA is worried enough about advances in the technology to start transitioning away from algorithms that are vulnerable to a quantum computer. Does this mean that the agency is close to a working prototype in their own classified labs? Unlikely. Does this mean that they envision practical quantum computers sooner than my 30-to-40-year estimate? Certainly.
Unlike most personal and corporate applications, the NSA routinely deals with information it wants kept secret for decades. Even so, we should all follow the NSA’s lead and transition our own systems to quantum-resistant algorithms over the next decade or so—possibly even sooner.
The essay previously appeared on Lawfare.
EDITED TO ADD: The computation that factored 143 also accidentally “factored much larger numbers such as 3599, 11663, and 56153, without the awareness of the authors of that work,” which shows how weird this all is.
EDITED TO ADD: Seems that I need to be clearer: I do not stand by my 30-40-year prediction. The NSA is acting like practical quantum computers will exist long before then, and I am deferring to their expertise.
Cryptography from the 13th Century
The British Museum wants help breaking a code on a 13th-century sword.
Another Salvo in the Second Crypto War (of Words)
Prosecutors from New York, London, Paris, and Madrid wrote an op-ed in yesterday’s New York Times in favor of backdoors in cell phone encryption. There are a number of flaws in their argument, ranging from how easy it is to get data off an encrypted phone to the dangers of designing a backdoor in the first place, but all of that has been said before. And since anecdote can be more persuasive than data, the op-ed started with one:
In June, a father of six was shot dead on a Monday afternoon in Evanston, Ill., a suburb 10 miles north of Chicago. The Evanston police believe that the victim, Ray C. Owens, had also been robbed. There were no witnesses to his killing, and no surveillance footage either.
With a killer on the loose and few leads at their disposal, investigators in Cook County, which includes Evanston, were encouraged when they found two smartphones alongside the body of the deceased: an iPhone 6 running on Apple’s iOS 8 operating system, and a Samsung Galaxy S6 Edge running on Google’s Android operating system. Both devices were passcode protected.
You can guess the rest. A judge issued a warrant, but neither Apple nor Google could unlock the phones. “The homicide remains unsolved. The killer remains at large.”
The Intercept researched the example, and it seems to be real. The phones belonged to the victim, and…
According to Commander Joseph Dugan of the Evanston Police Department, investigators were able to obtain records of the calls to and from the phones, but those records did not prove useful. By contrast, interviews with people who knew Owens suggested that he communicated mainly through text messages—the kind that travel as encrypted data—and had made plans to meet someone shortly before he was shot.
The information on his phone was not backed up automatically on Apple’s servers—apparently because he didn’t use wi-fi, which backups require.
[…]
But Dugan also wasn’t as quick to lay the blame solely on the encrypted phones. “I don’t know if getting in there, getting the information, would solve the case,” he said, “but it definitely would give us more investigative leads to follow up on.”
This is the first actual example I’ve seen illustrating the value of a backdoor. Unlike the increasingly common example of an ISIL handler abroad communicating securely with a radicalized person in the US, it’s an example where a backdoor might have helped. I say “might have,” because the Galaxy S6 is not encrypted by default, which means the victim deliberately turned the encryption on. If the native smartphone encryption had been backdoored, we don’t know if the victim would have turned it on nevertheless, or if he would have employed a different, non-backdoored, app.
The authors’ other examples are much sloppier:
Between October and June, 74 iPhones running the iOS 8 operating system could not be accessed by investigators for the Manhattan district attorney’s office—despite judicial warrants to search the devices. The investigations that were disrupted include the attempted murder of three individuals, the repeated sexual abuse of a child, a continuing sex trafficking ring and numerous assaults and robberies.
[…]
In France, smartphone data was vital to the swift investigation of the Charlie Hebdo terrorist attacks in January, and the deadly attack on a gas facility at Saint-Quentin-Fallavier, near Lyon, in June. And on a daily basis, our agencies rely on evidence lawfully retrieved from smartphones to fight sex crimes, child abuse, cybercrime, robberies or homicides.
We’ve heard that 74 number before. It’s over nine months, in an office that handles about 100,000 cases a year: less than 0.1% of the time. Details about those cases would be useful, so we can determine if encryption was just an impediment to investigation, or resulted in a criminal going free. The government needs to do a better job of presenting empirical data to support its case for backdoors. That they’re unable to do so suggests very strongly that an empirical analysis wouldn’t favor the government’s case.
As to the Charlie Hebdo case, it’s not clear how much of that vital smartphone data was actual data, and how much of it was unable-to-be-encrypted metadata. I am reminded of the examples that then-FBI-Director Louis Freeh would give during the First Crypto Wars in the 1990s. The big one used to illustrate the dangers of encryption was Mafia boss John Gotti. But the surveillance that convicted him was a room bug, not a wiretap. Given that the examples from FBI Director James Comey’s “going dark” speech last year were bogus, skepticism in the face of anecdote seems prudent.
So much of this “going dark” versus the “golden age of surveillance” debate depends on where you start from. Referring to that first Evanston example and the inability to get evidence from the victim’s phones, the op-ed authors write: “Until very recently, this situation would not have occurred.” That’s utter nonsense. From the beginning of time until very recently, this was the only situation that could have occurred. Objects in the vicinity of an event were largely mute about the past. Few things, save for eyewitnesses, could ever reach back in time and produce evidence. Even 15 years ago, the victim’s cell phone would have had no evidence on it that couldn’t have been obtained elsewhere, and that’s if the victim had been carrying a cell phone at all.
For most of human history, surveillance has been expensive. Over the last couple of decades, it has become incredibly cheap and almost ubiquitous. That a few bits and pieces are becoming expensive again isn’t a cause for alarm.
This essay originally appeared on Lawfare.
EDITED TO ADD (8/13): Excellent parody/commentary: “When Curtains Block Justice.”
Nicholas Weaver on iPhone Security
Excellent essay:
Yes, an iPhone configured with a proper password has enough protection that, turned off, I’d be willing to hand mine over to the DGSE, NSA, or Chinese. But many (perhaps most) users don’t configure their phones right. Beyond just waiting for the suspect to unlock his phone, most people either use a weak 4-digit passcode (that can be brute-forced) or use the fingerprint reader (which the officer has a day to force the subject to use).
Furthermore, most iPhones have a lurking security landmine enabled by default: iCloud backup. A simple warrant to Apple can obtain this backup, which includes all photographs (so there is the selfie) and all undeleted iMessages! About the only information of value not included in this backup are the known WiFi networks and the suspect’s email, but a suspect’s email is a different warrant away anyway.
Finally, there is iMessage, whose “end-to-end” nature, despite FBI complaints, contains some significant weaknesses and deserves scare-quotes. To start with, iMessage’s encryption does not obscure any metadata, and as the saying goes, “the Metadata is the Message”. So with a warrant to Apple, the FBI can obtain all the information about every message sent and received except the message contents, including time, IP addresses, recipients, and the presence and size of attachments. Apple can’t hide this metadata, because Apple needs to use this metadata to deliver messages.
He explains how Apple could enable surveillance on iMessage and FaceTime:
So to tap Alice, it is straightforward to modify the keyserver to present an additional FBI key for Alice to everyone but Alice. Now the FBI (but not Apple) can decrypt all iMessages sent to Alice in the future. A similar modification, adding an FBI key to every request Alice makes for any keys other than her own, enables tapping all messages sent by Alice. There are similar architectural vulnerabilities which enable tapping of “end-to-end secure” FaceTime calls.
There’s a persistent rumor going around that Apple is in the secret FISA Court, fighting a government order to make its platform more surveillance-friendly—and they’re losing. This might explain Apple CEO Tim Cook’s somewhat sudden vehemence about privacy. I have not found any confirmation of the rumor.
Backdoors Won't Solve Comey's Going Dark Problem
At the Aspen Security Forum two weeks ago, James Comey (and others) explicitly talked about the “going dark” problem, describing the specific scenario they are concerned about. Maybe others have heard the scenario before, but it was a first for me. It centers around ISIL operatives abroad and ISIL-inspired terrorists here in the US. The FBI knows who the Americans are, can get a court order to carry out surveillance on their communications, but cannot eavesdrop on the conversations, because they are encrypted. They can get the metadata, so they know who is talking to who, but they can’t find out what’s being said.
“ISIL’s M.O. is to broadcast on Twitter, get people to follow them, then move them to Twitter Direct Messaging” to evaluate if they are a legitimate recruit, he said. “Then they’ll move them to an encrypted mobile-messaging app so they go dark to us.”
[…]
The FBI can get court-approved access to Twitter exchanges, but not to encrypted communication, Comey said. Even when the FBI demonstrates probable cause and gets a judicial order to intercept that communication, it cannot break the encryption for technological reasons, according to Comey.
If this is what Comey and the FBI are actually concerned about, they’re getting bad advice—because their proposed solution won’t solve the problem. Comey wants communications companies to give them the capability to eavesdrop on conversations without the conversants’ knowledge or consent; that’s the “backdoor” we’re all talking about. But the problem isn’t that most encrypted communications platforms are securely encrypted, or even that some are—the problem is that there exists at least one securely encrypted communications platform on the planet that ISIL can use.
Imagine that Comey got what he wanted. Imagine that iMessage and Facebook and Skype and everything else US-made had his backdoor. The ISIL operative would tell his potential recruit to use something else, something secure and non-US-made. Maybe an encryption program from Finland, or Switzerland, or Brazil. Maybe Mujahedeen Secrets. Maybe anything. (Sure, some of these will have flaws, and they’ll be identifiable by their metadata, but the FBI already has the metadata, and the better software will rise to the top.) As long as there is something that the ISIL operative can move them to, some software that the American can download and install on their phone or computer, or hardware that they can buy from abroad, the FBI still won’t be able to eavesdrop.
And by pushing these ISIL operatives to non-US platforms, they lose access to the metadata they otherwise have.
Convincing US companies to install backdoors isn’t enough; in order to solve this going dark problem, the FBI has to ensure that an American can only use backdoored software. And the only way to do that is to prohibit the use of non-backdoored software, which is the sort of thing that the UK’s David Cameron said he wanted for his country in January:
But the question is are we going to allow a means of communications which it simply isn’t possible to read. My answer to that question is: no, we must not.
And that, of course, is impossible. Jonathan Zittrain explained why. And Cory Doctorow outlined what trying would entail:
For David Cameron’s proposal to work, he will need to stop Britons from installing software that comes from software creators who are out of his jurisdiction. The very best in secure communications are already free/open source projects, maintained by thousands of independent programmers around the world. They are widely available, and thanks to things like cryptographic signing, it is possible to download these packages from any server in the world (not just big ones like Github) and verify, with a very high degree of confidence, that the software you’ve downloaded hasn’t been tampered with.
[…]
This, then, is what David Cameron is proposing:
* All Britons’ communications must be easy for criminals, voyeurs and foreign spies to intercept.
* Any firms within reach of the UK government must be banned from producing secure software.
* All major code repositories, such as Github and Sourceforge, must be blocked.
* Search engines must not answer queries about web-pages that carry secure software.
* Virtually all academic security work in the UK must cease—security research must only take place in proprietary research environments where there is no onus to publish one’s findings, such as industry R&D and the security services.
* All packets in and out of the country, and within the country, must be subject to Chinese-style deep-packet inspection and any packets that appear to originate from secure software must be dropped.
* Existing walled gardens (like IOs and games consoles) must be ordered to ban their users from installing secure software.
* Anyone visiting the country from abroad must have their smartphones held at the border until they leave.
* Proprietary operating system vendors (Microsoft and Apple) must be ordered to redesign their operating systems as walled gardens that only allow users to run software from an app store, which will not sell or give secure software to Britons.
* Free/open source operating systems—that power the energy, banking, ecommerce, and infrastructure sectors—must be banned outright.
As extreme as it reads, without all of that, the ISIL operative would be able to communicate securely with his potential American recruit. And all of this is not going to happen.
Last week, former NSA director Mike McConnell, former DHS secretary Michael Chertoff, and former deputy defense secretary William Lynn published a Washington Post op-ed opposing backdoors in encryption software. They wrote:
Today, with almost everyone carrying a networked device on his or her person, ubiquitous encryption provides essential security. If law enforcement and intelligence organizations face a future without assured access to encrypted communications, they will develop technologies and techniques to meet their legitimate mission goals.
I believe this is true. Already one is being talked about in the academic literature: lawful hacking.
Perhaps the FBI’s reluctance to accept this is based on their belief that all encryption software comes from the US, and therefore is under their influence. Back in the 1990s, during the first Crypto Wars, the US government had a similar belief. To convince them otherwise, George Washington University surveyed the cryptography market in 1999 and found that there were over 500 companies in 70 countries manufacturing or distributing non-US cryptography products. Maybe we need a similar study today.
This essay previously appeared on Lawfare.
New RC4 Attack
New research: “All Your Biases Belong To Us: Breaking RC4 in WPA-TKIP and TLS,” by Mathy Vanhoef and Frank Piessens:
Abstract: We present new biases in RC4, break the Wi-Fi Protected Access Temporal Key Integrity Protocol (WPA-TKIP), and design a practical plaintext recovery attack against the Transport Layer Security (TLS) protocol. To empirically find new biases in the RC4 keystream we use statistical hypothesis tests. This reveals many new biases in the initial keystream bytes, as well as several new long-term biases. Our fixed-plaintext recovery algorithms are capable of using multiple types of biases, and return a list of plaintext candidates in decreasing likelihood.
To break WPA-TKIP we introduce a method to generate a large number of identical packets. This packet is decrypted by generating its plaintext candidate list, and using redundant packet structure to prune bad candidates. From the decrypted packet we derive the TKIP MIC key, which can be used to inject and decrypt packets. In practice the attack can be executed within an hour. We also attack TLS as used by HTTPS, where we show how to decrypt a secure cookie with a success rate of 94% using 9*227 ciphertexts. This is done by injecting known data around the cookie, abusing this using Mantin’s ABSAB bias, and brute-forcing the cookie by traversing the plaintext candidates. Using our traffic generation technique, we are able to execute the attack in merely 75 hours.
We need to deprecate the algorithm already.
Using Secure Chat
Micah Lee has a good tutorial on installing and using secure chat.
To recap: We have installed Orbot and connected to the Tor network on Android, and we have installed ChatSecure and created an anonymous secret identity Jabber account. We have added a contact to this account, started an encrypted session, and verified that their OTR fingerprint is correct. And now we can start chatting with them with an extraordinarily high degree of privacy.
FBI Director James Comey, UK Prime Minister David Cameron, and totalitarian governments around the world all don’t want you to be able to do this.
The Risks of Mandating Backdoors in Encryption Products
Tuesday, a group of cryptographers and security experts released a major paper outlining the risks of government-mandated back-doors in encryption products: Keys Under Doormats: Mandating insecurity by requiring government access to all data and communications, by Hal Abelson, Ross Anderson, Steve Bellovin, Josh Benaloh, Matt Blaze, Whitfield Diffie, John Gilmore, Matthew Green, Susan Landau, Peter Neumann, Ron Rivest, Jeff Schiller, Bruce Schneier, Michael Specter, and Danny Weitzner.
Abstract: Twenty years ago, law enforcement organizations lobbied to require data and communication services to engineer their products to guarantee law enforcement access to all data. After lengthy debate and vigorous predictions of enforcement channels going dark, these attempts to regulate the emerging Internet were abandoned. In the intervening years, innovation on the Internet flourished, and law enforcement agencies found new and more effective means of accessing vastly larger quantities of data. Today we are again hearing calls for regulation to mandate the provision of exceptional access mechanisms. In this report, a group of computer scientists and security experts, many of whom participated in a 1997 study of these same topics, has convened to explore the likely effects of imposing extraordinary access mandates. We have found that the damage that could be caused by law enforcement exceptional access requirements would be even greater today than it would have been 20 years ago. In the wake of the growing economic and social cost of the fundamental insecurity of today’s Internet environment, any proposals that alter the security dynamics online should be approached with caution. Exceptional access would force Internet system developers to reverse forward secrecy design practices that seek to minimize the impact on user privacy when systems are breached. The complexity of today’s Internet environment, with millions of apps and globally connected services, means that new law enforcement requirements are likely to introduce unanticipated, hard to detect security flaws. Beyond these and other technical vulnerabilities, the prospect of globally deployed exceptional access systems raises difficult problems about how such an environment would be governed and how to ensure that such systems would respect human rights and the rule of law.
It’s already had a big impact on the debate. It was mentioned several times during yesterday’s Senate hearing on the issue (see here).
Three blog posts by authors. Four different news articles, and this analysis of how the New York Times article changed. Also, a New York Times editorial.
EDITED TO ADD (7/9): Peter Swire’s Senate testimony is worth reading.
EDITED TO ADD (7/10): Good article on these new crypto wars.
EDITED TO ADF (7/14): Two rebuttals, neither very convincing.
More about the NSA's XKEYSCORE
I’ve been reading through the 48 classified documents about the NSA’s XKEYSCORE system released by the Intercept last week. From the article:
The NSA’s XKEYSCORE program, first revealed by The Guardian, sweeps up countless people’s Internet searches, emails, documents, usernames and passwords, and other private communications. XKEYSCORE is fed a constant flow of Internet traffic from fiber optic cables that make up the backbone of the world’s communication network, among other sources, for processing. As of 2008, the surveillance system boasted approximately 150 field sites in the United States, Mexico, Brazil, United Kingdom, Spain, Russia, Nigeria, Somalia, Pakistan, Japan, Australia, as well as many other countries, consisting of over 700 servers.
These servers store “full-take data” at the collection sites—meaning that they captured all of the traffic collected—and, as of 2009, stored content for 3 to 5 days and metadata for 30 to 45 days. NSA documents indicate that tens of billions of records are stored in its database. “It is a fully distributed processing and query system that runs on machines around the world,” an NSA briefing on XKEYSCORE says. “At field sites, XKEYSCORE can run on multiple computers that gives it the ability to scale in both processing power and storage.”
There seems to be no access controls at all restricting how analysts can use XKEYSCORE. Standing queries—called “workflows”—and new fingerprints have an approval process, presumably for load issues, but individual queries are not approved beforehand but may be audited after the fact. These are things which are supposed to be low latency, and you can’t have an approval process for low latency analyst queries. Since a query can get at the recorded raw data, a single query is effectively a retrospective wiretap.
All this means that the Intercept is correct when it writes:
These facts bolster one of Snowden’s most controversial statements, made in his first video interview published by The Guardian on June 9, 2013. “I, sitting at my desk,” said Snowden, could “wiretap anyone, from you or your accountant, to a federal judge to even the president, if I had a personal email.”
You’ll only get the data if it’s in the NSA’s databases, but if it is there you’ll get it.
Honestly, there’s not much in these documents that’s a surprise to anyone who studied the 2013 XKEYSCORE leaks and knows what can be done with a highly customizable Intrusion Detection System. But it’s always interesting to read the details.
One document—”Intro to Context Sensitive Scanning with X-KEYSCORE Fingerprints (2010)—talks about some of the queries an analyst can run. A sample scenario: “I want to look for people using Mojahedeen Secrets encryption from an iPhone” (page 6).
Mujahedeen Secrets is an encryption program written by al Qaeda supporters. It has been around since 2007. Last year, Stuart Baker cited its increased use as evidence that Snowden harmed America. I thought the opposite, that the NSA benefits from al Qaeda using this program. I wrote: “There’s nothing that screams ‘hack me’ more than using specially designed al Qaeda encryption software.”
And now we see how it’s done. In the document, we read about the specific XKEYSCORE queries an analyst can use to search for traffic encrypted by Mujahedeen Secrets. Here are some of the program’s fingerprints (page 10):
encryption/mojahaden2
encryption/mojahaden2/encodedheader
encryption/mojahaden2/hidden
encryption/mojahaden2/hidden2
encryption/mojahaden2/hidden44
encryption/mojahaden2/secure_file_cendode
encryption/mojahaden2/securefile
So if you want to search for all iPhone users of Mujahedeen Secrets (page 33):
fingerprint(‘demo/scenario4’)=
fingerprint(‘encryption/mojahdeen2’ and fingerprint(‘browser/cellphone/iphone’)
Or you can search for the program’s use in the encrypted text, because (page 37): “…many of the CT Targets are now smart enough not to leave the Mojahedeen Secrets header in the E-mails they send. How can we detect that the E-mail (which looks like junk) is in fact Mojahedeen Secrets encrypted text.” Summary of the answer: there are lots of ways to detect the use of this program that users can’t detect. And you can combine the use of Mujahedeen Secrets with other identifiers to find targets. For example, you can specifically search for the program’s use in extremist forums (page 9). (Note that the NSA wrote that comment about Mujahedeen Secrets users increasing their opsec in 2010, two years before Snowden supposedly told them that the NSA was listening on their communications. Honestly, I would not be surprised if the program turned out to have been a US operation to get Islamic radicals to make their traffic stand out more easily.)
It’s not just Mujahedeen Secrets. Nicholas Weaver explains how you can use XKEYSCORE to identify co-conspirators who are all using PGP.
And these searches are just one example. Other examples from the documents include:
- “Targets using mail.ru from a behind a large Iranian proxy” (here, page 7).
- Usernames and passwords of people visiting gov.ir (here, page 26 and following).
- People in Pakistan visiting certain German-language message boards (here, page 1).
- HTTP POST traffic from Russia in the middle of the night—useful for finding people trying to steal our data (here, page 16).
- People doing web searches on jihadist topics from Kabul (here).
E-mails, chats, web-browsing traffic, pictures, documents, voice calls, webcam photos, web searches, advertising analytics traffic, social media traffic, botnet traffic, logged keystrokes, file uploads to online services, Skype sessions and more: if you can figure out how to form the query, you can ask XKEYSCORE for it. For an example of how complex the searches can be, look at this XKEYSCORE query published in March, showing how New Zealand used the system to spy on the World Trade Organization: automatically track any email body with any particular WTO-related content for the upcoming election. (Good new documents to read include this, this, and this.)
I always read these NSA documents with an assumption that other countries are doing the same thing. The NSA is not made of magic, and XKEYSCORE is not some super-advanced NSA-only technology. It is the same sort of thing that every other country would use with its surveillance data. For example, Russia explicitly requires ISPs to install similar monitors as part of its SORM Internet surveillance system. As a home user, you can build your own XKEYSCORE using the public-domain Bro Security Monitor and the related Network Time Machine attached to a back-end data-storage system. (Lawrence Berkeley National Laboratory uses this system to store three months’ worth of Internet traffic for retrospective surveillance—it used the data to study Heartbleed.) The primary advantage the NSA has is that it sees more of the Internet than anyone else, and spends more money to store the data it intercepts for longer than anyone else. And if these documents explain XKEYSCORE in 2009 and 2010, expect that it’s much more powerful now.
Back to encryption and Mujahedeen Secrets. If you want to stay secure, whether you’re trying to evade surveillance by Russia, China, the NSA, criminals intercepting large amounts of traffic, or anyone else, try not to stand out. Don’t use some homemade specialized cryptography that can be easily identified by a system like this. Use reasonably strong encryption software on a reasonably secure device. If you trust Apple’s claims (pages 35-6), use iMessage and FaceTime on your iPhone. I really like Moxie Marlinspike’s Signal for both text and voice, but worry that it’s too obvious because it’s still rare. Ubiquitous encryption is the bane of listeners worldwide, and it’s the best thing we can deploy to make the world safer.
Sidebar photo of Bruce Schneier by Joe MacInnis.