Entries Tagged "encryption"

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Securing Communications in a Trump Administration

Susan Landau has an excellent essay on why it’s more important than ever to have backdoor-free encryption on our computer and communications systems.

Protecting the privacy of speech is crucial for preserving our democracy. We live at a time when tracking an individual—­a journalist, a member of the political opposition, a citizen engaged in peaceful protest­—or listening to their communications is far easier than at any time in human history. Political leaders on both sides now have a responsibility to work for securing communications and devices. This means supporting not only the laws protecting free speech and the accompanying communications, but also the technologies to do so: end-to-end encryption and secured devices; it also means soundly rejecting all proposals for front-door exceptional access. Prior to the election there were strong, sound security arguments for rejecting such proposals. The privacy arguments have now, suddenly, become critically important as well. Threatened authoritarianism means that we need technological protections for our private communications every bit as much as we need the legal ones we presently have.

Unfortunately, the trend is moving in the other direction. The UK just passed the Investigatory Powers Act, giving police and intelligence agencies incredibly broad surveillance powers with very little oversight. And Bits of Freedom just reported that “Croatia, Italy, Latvia, Poland and Hungary all want an EU law to be created to help their law enforcement authorities access encrypted information and share data with investigators in other countries.”

Posted on November 23, 2016 at 2:01 PMView Comments

Whistleblower Investigative Report on NSA Suite B Cryptography

The NSA has been abandoning secret and proprietary cryptographic algorithms in favor of commercial public algorithms, generally known as “Suite B.” In 2010, an NSA employee filed some sort of whistleblower complaint, alleging that this move is both insecure and wasteful. The US DoD Inspector General investigated and wrote a report in 2011.

The report—slightly redacted and declassified—found that there was no wrongdoing. But the report is an interesting window into the NSA’s system of algorithm selection and testing (pages 5 and 6), as well as how they investigate whistleblower complaints.

Posted on November 9, 2016 at 12:00 PMView Comments

Self-Propagating Smart Light Bulb Worm

This is exactly the sort of Internet-of-Things attack that has me worried:

“IoT Goes Nuclear: Creating a ZigBee Chain Reaction” by Eyal Ronen, Colin OFlynn, Adi Shamir and Achi-Or Weingarten.

Abstract: Within the next few years, billions of IoT devices will densely populate our cities. In this paper we describe a new type of threat in which adjacent IoT devices will infect each other with a worm that will spread explosively over large areas in a kind of nuclear chain reaction, provided that the density of compatible IoT devices exceeds a certain critical mass. In particular, we developed and verified such an infection using the popular Philips Hue smart lamps as a platform. The worm spreads by jumping directly from one lamp to its neighbors, using only their built-in ZigBee wireless connectivity and their physical proximity. The attack can start by plugging in a single infected bulb anywhere in the city, and then catastrophically spread everywhere within minutes, enabling the attacker to turn all the city lights on or off, permanently brick them, or exploit them in a massive DDOS attack. To demonstrate the risks involved, we use results from percolation theory to estimate the critical mass of installed devices for a typical city such as Paris whose area is about 105 square kilometers: The chain reaction will fizzle if there are fewer than about 15,000 randomly located smart lights in the whole city, but will spread everywhere when the number exceeds this critical mass (which had almost certainly been surpassed already).

To make such an attack possible, we had to find a way to remotely yank already installed lamps from their current networks, and to perform over-the-air firmware updates. We overcame the first problem by discovering and exploiting a major bug in the implementation of the Touchlink part of the ZigBee Light Link protocol, which is supposed to stop such attempts with a proximity test. To solve the second problem, we developed a new version of a side channel attack to extract the global AES-CCM key that Philips uses to encrypt and authenticate new firmware. We used only readily available equipment costing a few hundred dollars, and managed to find this key without seeing any actual updates. This demonstrates once again how difficult it is to get security right even for a large company that uses standard cryptographic techniques to protect a major product.

EDITED TO ADD: BoingBoing post. Slashdot thread.

Posted on November 9, 2016 at 6:54 AMView Comments

Teaching a Neural Network to Encrypt

Researchers have trained a neural network to encrypt its communications.

In their experiment, computers were able to make their own form of encryption using machine learning, without being taught specific cryptographic algorithms. The encryption was very basic, especially compared to our current human-designed systems. Even so, it is still an interesting step for neural nets, which the authors state “are generally not meant to be great at cryptography:.

This story is more about AI and neural networks than it is about cryptography. The algorithm isn’t any good, but is a perfect example of what I’ve heard called “Schneier’s Law“: Anyone can design a cipher that they themselves cannot break.

Research paper. Note that the researchers work at Google.

Posted on November 3, 2016 at 6:05 AMView Comments

Recovering an iPhone 5c Passcode

Remember the San Bernardino killer’s iPhone, and how the FBI maintained that they couldn’t get the encryption key without Apple providing them with a universal backdoor? Many of us computer-security experts said that they were wrong, and there were several possible techniques they could use. One of them was manually removing the flash chip from the phone, extracting the memory, and then running a brute-force attack without worrying about the phone deleting the key.

The FBI said it was impossible. We all said they were wrong. Now, Sergei Skorobogatov has proved them wrong. Here’s his paper:

Abstract: This paper is a short summary of a real world mirroring attack on the Apple iPhone 5c passcode retry counter under iOS 9. This was achieved by desoldering the NAND Flash chip of a sample phone in order to physically access its connection to the SoC and partially reverse engineering its proprietary bus protocol. The process does not require any expensive and sophisticated equipment. All needed parts are low cost and were obtained from local electronics distributors. By using the described and successful hardware mirroring process it was possible to bypass the limit on passcode retry attempts. This is the first public demonstration of the working prototype and the real hardware mirroring process for iPhone 5c. Although the process can be improved, it is still a successful proof-of-concept project. Knowledge of the possibility of mirroring will definitely help in designing systems with better protection. Also some reliability issues related to the NAND memory allocation in iPhone 5c are revealed. Some future research directions are outlined in this paper and several possible countermeasures are suggested. We show that claims that iPhone 5c NAND mirroring was infeasible were ill-advised.

Susan Landau explains why this is important:

The moral of the story? It’s not, as the FBI has been requesting, a bill to make it easier to access encrypted communications, as in the proposed revised Burr-Feinstein bill. Such “solutions” would make us less secure, not more so. Instead we need to increase law enforcement’s capabilities to handle encrypted communications and devices. This will also take more funding as well as redirection of efforts. Increased security of our devices and simultaneous increased capabilities of law enforcement are the only sensible approach to a world where securing the bits, whether of health data, financial information, or private emails, has become of paramount importance.

Or: The FBI needs computer-security expertise, not backdoors.

Patrick Ball writes about the dangers of backdoors.

EDITED TO ADD (9/23): Good article from the Economist.

Posted on September 15, 2016 at 8:54 AMView Comments

Google's Post-Quantum Cryptography

News has been bubbling about an announcement by Google that it’s starting to experiment with public-key cryptography that’s resistant to cryptanalysis by a quantum computer. Specifically, it’s experimenting with the New Hope algorithm.

It’s certainly interesting that Google is thinking about this, and probably okay that it’s available in the Canary version of Chrome, but this algorithm is by no means ready for operational use. Secure public-key algorithms are very hard to create, and this one has not had nearly enough analysis to be trusted. Lattice-based public-key cryptosystems such as New Hope are particularly subtle—and we cryptographers are still learning a lot about how they can be broken.

Targets are important in cryptography, and Google has turned New Hope into a good one. Consider this an opportunity to advance our cryptographic knowledge, not an offer of a more-secure encryption option. And this is the right time for this area of research, before quantum computers make discrete-logarithm and factoring algorithms obsolete.

Posted on July 12, 2016 at 12:53 PMView Comments

Comparing Messaging Apps

Micah Lee has a nice comparison among Signal, WhatsApp, and Allo.

In this article, I’m going to compare WhatsApp, Signal, and Allo from a privacy perspective.

While all three apps use the same secure-messaging protocol, they differ on exactly what information is encrypted, what metadata is collected, and what, precisely, is stored in the cloud ­- and therefore available, in theory at least, to government snoops and wily hackers.

In the end, I’m going to advocate you use Signal whenever you can -­ which actually may not end up being as often as you would like.

EDITED TO ADD (6/25): Don’t use Telegram.

Posted on June 23, 2016 at 6:54 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.