Entries Tagged "cryptography"

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Update on NIST's Post-Quantum Cryptography Program

NIST has posted an update on their post-quantum cryptography program:

After spending more than three years examining new approaches to encryption and data protection that could defeat an assault from a quantum computer, the National Institute of Standards and Technology (NIST) has winnowed the 69 submissions it initially received down to a final group of 15. NIST has now begun the third round of public review. This “selection round” will help the agency decide on the small subset of these algorithms that will form the core of the first post-quantum cryptography standard.


For this third round, the organizers have taken the novel step of dividing the remaining candidate algorithms into two groups they call tracks. The first track contains the seven algorithms that appear to have the most promise.

“We’re calling these seven the finalists,” Moody said. “For the most part, they’re general-purpose algorithms that we think could find wide application and be ready to go after the third round.”

The eight alternate algorithms in the second track are those that either might need more time to mature or are tailored to more specific applications. The review process will continue after the third round ends, and eventually some of these second-track candidates could become part of the standard. Because all of the candidates still in play are essentially survivors from the initial group of submissions from 2016, there will also be future consideration of more recently developed ideas, Moody said.

“The likely outcome is that at the end of this third round, we will standardize one or two algorithms for encryption and key establishment, and one or two others for digital signatures,” he said. “But by the time we are finished, the review process will have been going on for five or six years, and someone may have had a good idea in the interim. So we’ll find a way to look at newer approaches too.”

Details are here. This is all excellent work, and exemplifies NIST at its best. The quantum-resistant algorithms will be standardized far in advance of any practical quantum computer, which is how we all want this sort of thing to go.

Posted on July 24, 2020 at 6:36 AMView Comments

NSA on Securing VPNs

The NSA’s Cybersecurity Directorate—that’s the part that’s supposed to work on defense—has released two documents (a full and an abridged version) on securing virtual private networks. Some of it is basic, but it contains good information.

Maintaining a secure VPN tunnel can be complex and requires regular maintenance. To maintain a secure VPN, network administrators should perform the following tasks on a regular basis:

  • Reduce the VPN gateway attack surface
  • Verify that cryptographic algorithms are Committee on National Security Systems Policy (CNSSP) 15-compliant
  • Avoid using default VPN settings
  • Remove unused or non-compliant cryptography suites
  • Apply vendor-provided updates (i.e. patches) for VPN gateways and clients

Posted on July 15, 2020 at 9:29 AMView Comments

Another Story of Bad 1970s Encryption

This one is from the Netherlands. It seems to be clever cryptanalysis rather than a backdoor.

The Dutch intelligence service has been able to read encrypted communications from dozens of countries since the late 1970s thanks to a microchip, according to research by de Volkskrant on Thursday. The Netherlands could eavesdrop on confidential communication from countries such as Iran, Egypt and Saudi Arabia.

Philips, together with Siemens, built an encryption machine in the late 1970s. The device, the Aroflex, was used for secret communication between NATO allies. In addition, the companies also wanted to market the T1000CA, a commercial variant of the Aroflex with less strong cryptography.

The Volkskrant investigation shows that the Ministry of Foreign Affairs and the Marine Intelligence Service (MARID) cracked the cryptography of this device before it was launched. Philips helped the ministry and the intelligence service.

Normally it would take at least a month and a half to crack the T1000CA encryption. “Too long to get useful information from intercepted communication,” the newspaper writes. But MARID employees, together with Philips, succeeded in accelerating this 2.500 times by developing a special microchip.

The T1000CA was then sold to numerous non-NATO countries, including the Middle East and Asia. These countries could then be overheard by the Dutch intelligence services for years.

The 1970s was a decade of really bad commercial cryptography. DES, in 1975, was an improvement with its 56-bit key. I’m sure there are lots of these stories.

Here’s more about the Aroflex. And here’s what I think is the original Dutch story.

Posted on April 21, 2020 at 6:22 AMView Comments

RSA-250 Factored

RSA-250 has been factored.

This computation was performed with the Number Field Sieve algorithm,
using the open-source CADO-NFS software.

The total computation time was roughly 2700 core-years, using Intel Xeon Gold 6130 CPUs as a reference (2.1GHz):

RSA-250 sieving: 2450 physical core-years
RSA-250 matrix: 250 physical core-years

The computation involved tens of thousands of machines worldwide, and was completed in a few months.

News article. On the factoring challenges.

Posted on April 8, 2020 at 6:37 AMView Comments


Prepare for another attack on encryption in the U.S. The EARN-IT Act purports to be about protecting children from predation, but it’s really about forcing the tech companies to break their encryption schemes:

The EARN IT Act would create a “National Commission on Online Child Sexual Exploitation Prevention” tasked with developing “best practices” for owners of Internet platforms to “prevent, reduce, and respond” to child exploitation. But far from mere recommendations, those “best practices” would be approved by Congress as legal requirements: if a platform failed to adhere to them, it would lose essential legal protections for free speech.

It’s easy to predict how Attorney General William Barr would use that power: to break encryption. He’s said over and over that he thinks the “best practice” is to force encrypted messaging systems to give law enforcement access to our private conversations. The Graham-Blumenthal bill would finally give Barr the power to demand that tech companies obey him or face serious repercussions, including both civil and criminal liability. Such a demand would put encryption providers like WhatsApp and Signal in an awful conundrum: either face the possibility of losing everything in a single lawsuit or knowingly undermine their users’ security, making all of us more vulnerable to online criminals.

Matthew Green has a long explanation of the bill and its effects:

The new bill, out of Lindsey Graham’s Judiciary committee, is designed to force providers to either solve the encryption-while-scanning problem, or stop using encryption entirely. And given that we don’t yet know how to solve the problem—and the techniques to do it are basically at the research stage of R&D—it’s likely that “stop using encryption” is really the preferred goal.

EARN IT works by revoking a type of liability called Section 230 that makes it possible for providers to operate on the Internet, by preventing the provider for being held responsible for what their customers do on a platform like Facebook. The new bill would make it financially impossible for providers like WhatsApp and Apple to operate services unless they conduct “best practices” for scanning their systems for CSAM.

Since there are no “best practices” in existence, and the techniques for doing this while preserving privacy are completely unknown, the bill creates a government-appointed committee that will tell technology providers what technology they have to use. The specific nature of the committee is byzantine and described within the bill itself. Needless to say, the makeup of the committee, which can include as few as zero data security experts, ensures that end-to-end encryption will almost certainly not be considered a best practice.

So in short: this bill is a backdoor way to allow the government to ban encryption on commercial services. And even more beautifully: it doesn’t come out and actually ban the use of encryption, it just makes encryption commercially infeasible for major providers to deploy, ensuring that they’ll go bankrupt if they try to disobey this committee’s recommendations.

It’s the kind of bill you’d come up with if you knew the thing you wanted to do was unconstitutional and highly unpopular, and you basically didn’t care.

Another criticism of the bill. Commentary by EPIC. Kinder analysis.

Sign a petition against this act.

Posted on March 13, 2020 at 6:20 AMView Comments

More on Crypto AG

One follow-on to the story of Crypto AG being owned by the CIA: this interview with a Washington Post reporter. The whole thing is worth reading or listening to, but I was struck by these two quotes at the end:

…in South America, for instance, many of the governments that were using Crypto machines were engaged in assassination campaigns. Thousands of people were being disappeared, killed. And I mean, they’re using Crypto machines, which suggests that the United States intelligence had a lot of insight into what was happening. And it’s hard to look back at that history now and see a lot of evidence of the United States going to any real effort to stop it or at least or even expose it.


To me, the history of the Crypto operation helps to explain how U.S. spy agencies became accustomed to, if not addicted to, global surveillance. This program went on for more than 50 years, monitoring the communications of more than 100 countries. I mean, the United States came to expect that kind of penetration, that kind of global surveillance capability. And as Crypto became less able to deliver it, the United States turned to other ways to replace that. And the Snowden documents tell us a lot about how they did that.

Posted on March 6, 2020 at 7:48 AMView Comments

Policy vs. Technology

Sometime around 1993 or 1994, during the first Crypto Wars, I was part of a group of cryptography experts that went to Washington to advocate for strong encryption. Matt Blaze and Ron Rivest were with me; I don’t remember who else. We met with then Massachusetts Representative Ed Markey. (He didn’t become a senator until 2013.) Back then, he and Vermont Senator Patrick Leahy were the most knowledgeable on this issue and our biggest supporters against government backdoors. They still are.

Markey was against forcing encrypted phone providers to implement the NSA’s Clipper Chip in their devices, but wanted us to reach a compromise with the FBI regardless. This completely startled us techies, who thought having the right answer was enough. It was at that moment that I learned an important difference between technologists and policy makers. Technologists want solutions; policy makers want consensus.

Since then, I have become more immersed in policy discussions. I have spent more time with legislators, advised advocacy organizations like EFF and EPIC, and worked with policy-minded think tanks in the United States and around the world. I teach cybersecurity policy and technology at the Harvard Kennedy School of Government. My most recent two books, Data and Goliath—about surveillance—and Click Here to Kill Everybody—about IoT security—are really about the policy implications of technology.

Over that time, I have observed many other differences between technologists and policy makers—differences that we in cybersecurity need to understand if we are to translate our technological solutions into viable policy outcomes.

Technologists don’t try to consider all of the use cases of a given technology. We tend to build something for the uses we envision, and hope that others can figure out new and innovative ways to extend what we created. We love it when there is a new use for a technology that we never considered and that changes the world. And while we might be good at security around the use cases we envision, we are regularly blindsided when it comes to new uses or edge cases. (Authentication risks surrounding someone’s intimate partner is a good example.)

Policy doesn’t work that way; it’s specifically focused on use. It focuses on people and what they do. Policy makers can’t create policy around a piece of technology without understanding how it is used—how all of it’s used.

Policy is often driven by exceptional events, like the FBI’s desire to break the encryption on the San Bernardino shooter’s iPhone. (The PATRIOT Act is the most egregious example I can think of.) Technologists tend to look at more general use cases, like the overall value of strong encryption to societal security. Policy tends to focus on the past, making existing systems work or correcting wrongs that have happened. It’s hard to imagine policy makers creating laws around VR systems, because they don’t yet exist in any meaningful way. Technology is inherently future focused. Technologists try to imagine better systems, or future flaws in present systems, and work to improve things.

As technologists, we iterate. It’s how we write software. It’s how we field products. We know we can’t get it right the first time, so we have developed all sorts of agile systems to deal with that fact. Policy making is often the opposite. U.S. federal laws take months or years to negotiate and pass, and after that the issue doesn’t get addressed again for a decade or more. It is much more critical to get it right the first time, because the effects of getting it wrong are long lasting. (See, for example, parts of the GDPR.) Sometimes regulatory agencies can be more agile. The courts can also iterate policy, but it’s slower.

Along similar lines, the two groups work in very different time frames. Engineers, conditioned by Moore’s law, have long thought of 18 months as the maximum time to roll out a new product, and now think in terms of continuous deployment of new features. As I said previously, policy makers tend to think in terms of multiple years to get a law or regulation in place, and then more years as the case law builds up around it so everyone knows what it really means. It’s like tortoises and hummingbirds.

Technology is inherently global. It is often developed with local sensibilities according to local laws, but it necessarily has global reach. Policy is always jurisdictional. This difference is causing all sorts of problems for the global cloud services we use every day. The providers are unable to operate their global systems in compliance with more than 200 different—and sometimes conflicting—national requirements. Policy makers are often unimpressed with claims of inability; laws are laws, they say, and if Facebook can translate its website into French for the French, it can also implement their national laws.

Technology and policy both use concepts of trust, but differently. Technologists tend to think of trust in terms of controls on behavior. We’re getting better—NIST’s recent work on trust is a good example—but we have a long way to go. For example, Google’s Trust and Safety Department does a lot of AI and ethics work largely focused on technological controls. Policy makers think of trust in more holistic societal terms: trust in institutions, trust as the ability not to worry about adverse outcomes, consumer confidence. This dichotomy explains how techies can claim bitcoin is trusted because of the strong cryptography, but policy makers can’t imagine calling a system trustworthy when you lose all your money if you forget your encryption key.

Policy is how society mediates how individuals interact with society. Technology has the potential to change how individuals interact with society. The conflict between these two causes considerable friction, as technologists want policy makers to get out of the way and not stifle innovation, and policy makers want technologists to stop moving fast and breaking so many things.

Finally, techies know that code is law­—that the restrictions and limitations of a technology are more fundamental than any human-created legal anything. Policy makers know that law is law, and tech is just tech. We can see this in the tension between applying existing law to new technologies and creating new law specifically for those new technologies.

Yes, these are all generalizations and there are exceptions. It’s also not all either/or. Great technologists and policy makers can see the other perspectives. The best policy makers know that for all their work toward consensus, they won’t make progress by redefining pi as three. Thoughtful technologists look beyond the immediate user demands to the ways attackers might abuse their systems, and design against those adversaries as well. These aren’t two alien species engaging in first contact, but cohorts who can each learn and borrow tools from the other. Too often, though, neither party tries.

In October, I attended the first ACM Symposium on Computer Science and the Law. Google counsel Brian Carver talked about his experience with the few computer science grad students who would attend his Intellectual Property and Cyberlaw classes every year at UC Berkeley. One of the first things he would do was give the students two different cases to read. The cases had nearly identical facts, and the judges who’d ruled on them came to exactly opposite conclusions. The law students took this in stride; it’s the way the legal system works when it’s wrestling with a new concept or idea. But it shook the computer science students. They were appalled that there wasn’t a single correct answer.

But that’s not how law works, and that’s not how policy works. As the technologies we’re creating become more central to society, and as we in technology continue to move into the public sphere and become part of the increasingly important policy debates, it is essential that we learn these lessons. Gone are the days when we were creating purely technical systems and our work ended at the keyboard and screen. Now we’re building complex socio-technical systems that are literally creating a new world. And while it’s easy to dismiss policy makers as doing it wrong, it’s important to understand that they’re not. Policy making has been around a lot longer than the Internet or computers or any technology. And the essential challenges of this century will require both groups to work together.

This essay previously appeared in IEEE Security & Privacy.

EDITED TO ADD (3/16): This essay has been translated into Spanish.

Posted on February 21, 2020 at 5:54 AMView Comments

Crypto AG Was Owned by the CIA

The Swiss cryptography firm Crypto AG sold equipment to governments and militaries around the world for decades after World War II. They were owned by the CIA:

But what none of its customers ever knew was that Crypto AG was secretly owned by the CIA in a highly classified partnership with West German intelligence. These spy agencies rigged the company’s devices so they could easily break the codes that countries used to send encrypted messages.

This isn’t really news. We have long known that Crypto AG was backdooring crypto equipment for the Americans. What is new is the formerly classified documents describing the details:

The decades-long arrangement, among the most closely guarded secrets of the Cold War, is laid bare in a classified, comprehensive CIA history of the operation obtained by The Washington Post and ZDF, a German public broadcaster, in a joint reporting project.

The account identifies the CIA officers who ran the program and the company executives entrusted to execute it. It traces the origin of the venture as well as the internal conflicts that nearly derailed it. It describes how the United States and its allies exploited other nations’ gullibility for years, taking their money and stealing their secrets.

The operation, known first by the code name “Thesaurus” and later “Rubicon,” ranks among the most audacious in CIA history.

EDITED TO ADD: More news articles. And a 1995 story on this. It’s not new news.

Posted on February 11, 2020 at 10:42 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.