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On the Subversion of NIST by the NSA

Nadiya Kostyuk and Susan Landau wrote an interesting paper: “Dueling Over DUAL_EC_DRBG: The Consequences of Corrupting a Cryptographic Standardization Process”:

Abstract: In recent decades, the U.S. National Institute of Standards and Technology (NIST), which develops cryptographic standards for non-national security agencies of the U.S. government, has emerged as the de facto international source for cryptographic standards. But in 2013, Edward Snowden disclosed that the National Security Agency had subverted the integrity of a NIST cryptographic standard­the Dual_EC_DRBG­enabling easy decryption of supposedly secured communications. This discovery reinforced the desire of some public and private entities to develop their own cryptographic standards instead of relying on a U.S. government process. Yet, a decade later, no credible alternative to NIST has emerged. NIST remains the only viable candidate for effectively developing internationally trusted cryptography standards.

Cryptographic algorithms are essential to security yet are hard to understand and evaluate. These technologies provide crucial security for communications protocols. Yet the protocols transit international borders; they are used by countries that do not necessarily trust each other. In particular, these nations do not necessarily trust the developer of the cryptographic standard.

Seeking to understand how NIST, a U.S. government agency, was able to remain a purveyor of cryptographic algorithms despite the Dual_EC_DRBG problem, we examine the Dual_EC_DRBG situation, NIST’s response, and why a non-regulatory, non-national security U.S. agency remains a successful international supplier of strong cryptographic solutions.

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Posted on June 23, 2022 at 6:05 AM • View Comments

Symbiote Backdoor in Linux

Interesting:

What makes Symbiote different from other Linux malware that we usually come across, is that it needs to infect other running processes to inflict damage on infected machines. Instead of being a standalone executable file that is run to infect a machine, it is a shared object (SO) library that is loaded into all running processes using LD_PRELOAD (T1574.006), and parasitically infects the machine. Once it has infected all the running processes, it provides the threat actor with rootkit functionality, the ability to harvest credentials, and remote access capability.

News article:

Researchers have unearthed a discovery that doesn’t occur all that often in the realm of malware: a mature, never-before-seen Linux backdoor that uses novel evasion techniques to conceal its presence on infected servers, in some cases even with a forensic investigation.

No public attribution yet.

So far, there’s no evidence of infections in the wild, only malware samples found online. It’s unlikely this malware is widely active at the moment, but with stealth this robust, how can we be sure?

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Posted on June 22, 2022 at 6:07 AM • View Comments

Hidden Anti-Cryptography Provisions in Internet Anti-Trust Bills

Two bills attempting to reduce the power of Internet monopolies are currently being debated in Congress: S. 2992, the American Innovation and Choice Online Act; and S. 2710, the Open App Markets Act. Reducing the power to tech monopolies would do more to “fix” the Internet than any other single action, and I am generally in favor of them both. (The Center for American Progress wrote a good summary and evaluation of them. I have written in support of the bill that would force Google and Apple to give up their monopolies on their phone app stores.)

There is a significant problem, though. Both bills have provisions that could be used to break end-to-end encryption.

Let’s start with S. 2992. Sec. 3(c)(7)(A)(iii) would allow a company to deny access to apps installed by users, where those app makers “have been identified [by the Federal Government] as national security, intelligence, or law enforcement risks.” That language is far too broad. It would allow Apple to deny access to an encryption service provider that provides encrypted cloud backups to the cloud (which Apple does not currently offer). All Apple would need to do is point to any number of FBI materials decrying the security risks with “warrant proof encryption.”

Sec. 3(c)(7)(A)(vi) states that there shall be no liability for a platform “solely” because it offers “end-to-end encryption.” This language is too narrow. The word “solely” suggests that offering end-to-end encryption could be a factor in determining liability, provided that it is not the only reason. This is very similar to one of the problems with the encryption carve-out in the EARN IT Act. The section also doesn’t mention any other important privacy-protective features and policies, which also shouldn’t be the basis for creating liability for a covered platform under Sec. 3(a).

In Sec. 2(a)(2), the definition of business user excludes any person who “is a clear national security risk.” This term is undefined, and as such far too broad. It can easily be interpreted to cover any company that offers an end-to-end encrypted alternative, or a service offered in a country whose privacy laws forbid disclosing data in response to US court-ordered surveillance. Again, the FBI’s repeated statements about end-to-end encryption could serve as support.

Finally, under Sec. 3(b)(2)(B), platforms have an affirmative defense for conduct that would otherwise violate the Act if they do so in order to “protect safety, user privacy, the security of nonpublic data, or the security of the covered platform.” This language is too vague, and could be used to deny users the ability to use competing services that offer better security/privacy than the incumbent platform—particularly where the platform offers subpar security in the name of “public safety.” For example, today Apple only offers unencrypted iCloud backups, which it can then turn over governments who claim this is necessary for “public safety.” Apple can raise this defense to justify its blocking third-party services from offering competing, end-to-end encrypted backups of iMessage and other sensitive data stored on an iPhone.

S. 2710 has similar problems. Sec 7. (6)(B) contains language specifying that the bill does not “require a covered company to interoperate or share data with persons or business users that…have been identified by the Federal Government as national security, intelligence, or law enforcement risks.” This would mean that Apple could ignore the prohibition against private APIs, and deny access to otherwise private APIs, for developers of encryption products that have been publicly identified by the FBI. That is, end-to-end encryption products.

I want those bills to pass, but I want those provisions cleared up so we don’t lose strong end-to-end encryption in our attempt to reign in the tech monopolies.

EDITED TO ADD (6/23): A few DC insiders have responded to me about this post. Their basic point is this: “Your threat model is wrong. The big tech companies can already break end-to-end encryption if they want. They don’t need any help, and this bill doesn’t give the FBI any new leverage they don’t already have. This bill doesn’t make anything any worse than it is today.” That’s a reasonable response. These bills are definitely a net positive for humanity.

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Posted on June 21, 2022 at 6:34 AM • View Comments

Hertzbleed: A New Side-Channel Attack

Hertzbleed is a new side-channel attack that works against a variety of microprocressors. Deducing cryptographic keys by analyzing power consumption has long been an attack, but it’s not generally viable because measuring power consumption is often hard. This new attack measures power consumption by measuring time, making it easier to exploit.

The team discovered that dynamic voltage and frequency scaling (DVFS)—a power and thermal management feature added to every modern CPU—allows attackers to deduce the changes in power consumption by monitoring the time it takes for a server to respond to specific carefully made queries. The discovery greatly reduces what’s required. With an understanding of how the DVFS feature works, power side-channel attacks become much simpler timing attacks that can be done remotely.

The researchers have dubbed their attack Hertzbleed because it uses the insights into DVFS to expose­or bleed out­data that’s expected to remain private.

[…]

The researchers have already shown how the exploit technique they developed can be used to extract an encryption key from a server running SIKE, a cryptographic algorithm used to establish a secret key between two parties over an otherwise insecure communications channel.

The researchers said they successfully reproduced their attack on Intel CPUs from the 8th to the 11th generation of the Core microarchitecture. They also claimed that the technique would work on Intel Xeon CPUs and verified that AMD Ryzen processors are vulnerable and enabled the same SIKE attack used against Intel chips. The researchers believe chips from other manufacturers may also be affected.

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Posted on June 20, 2022 at 6:23 AM • View Comments

Tracking People via Bluetooth on Their Phones

We’ve always known that phones—and the people carrying them—can be uniquely identified from their Bluetooth signatures, and that we need security techniques to prevent that. This new research shows that that’s not enough.

Computer scientists at the University of California San Diego proved in a study published May 24 that minute imperfections in phones caused during manufacturing create a unique Bluetooth beacon, one that establishes a digital signature or fingerprint distinct from any other device. Though phones’ Bluetooth uses cryptographic technology that limits trackability, using a radio receiver, these distortions in the Bluetooth signal can be discerned to track individual devices.

[…]

The study’s scientists conducted tests to show whether multiple phones being in one place could disrupt their ability to track individual signals. Results in an initial experiment showed they managed to discern individual signals for 40% of 162 devices in public. Another, scaled-up experiment showed they could discern 47% of 647 devices in a public hallway across two days.

The tracking range depends on device and the environment, and it could be several hundred feet, but in a crowded location it might only be 10 or so feet. Scientists were able to follow a volunteer’s signal as they went to and from their house. Certain environmental factors can disrupt a Bluetooth signal, including changes in environment temperature, and some devices send signals with more power and range than others.

One might say “well, I’ll just keep Bluetooth turned off when not in use,” but the researchers said they found that some devices, especially iPhones, don’t actually turn off Bluetooth unless a user goes directly into settings to turn off the signal. Most people might not even realize their Bluetooth is being constantly emitted by many smart devices.

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Posted on June 17, 2022 at 6:06 AM • View Comments

Attacking the Performance of Machine Learning Systems

Interesting research: “Sponge Examples: Energy-Latency Attacks on Neural Networks“:

Abstract: The high energy costs of neural network training and inference led to the use of acceleration hardware such as GPUs and TPUs. While such devices enable us to train large-scale neural networks in datacenters and deploy them on edge devices, their designers’ focus so far is on average-case performance. In this work, we introduce a novel threat vector against neural networks whose energy consumption or decision latency are critical. We show how adversaries can exploit carefully-crafted sponge examples, which are inputs designed to maximise energy consumption and latency, to drive machine learning (ML) systems towards their worst-case performance. Sponge examples are, to our knowledge, the first denial-of-service attack against the ML components of such systems. We mount two variants of our sponge attack on a wide range of state-of-the-art neural network models, and find that language models are surprisingly vulnerable. Sponge examples frequently increase both latency and energy consumption of these models by a factor of 30×. Extensive experiments show that our new attack is effective across different hardware platforms (CPU, GPU and an ASIC simulator) on a wide range of different language tasks. On vision tasks, we show that sponge examples can be produced and a latency degradation observed, but the effect is less pronounced. To demonstrate the effectiveness of sponge examples in the real world, we mount an attack against Microsoft Azure’s translator and show an increase of response time from 1ms to 6s (6000×). We conclude by proposing a defense strategy: shifting the analysis of energy consumption in hardware from an average-case to a worst-case perspective.

Attackers were able to degrade the performance so much, and force the system to waste so many cycles, that some hardware would shut down due to overheating. Definitely a “novel threat vector.”

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Posted on June 16, 2022 at 6:02 AM • View Comments

M1 Chip Vulnerability

This is a new vulnerability against Apple’s M1 chip. Researchers say that it is unpatchable.

Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory, however, have created a novel hardware attack, which combines memory corruption and speculative execution attacks to sidestep the security feature. The attack shows that pointer authentication can be defeated without leaving a trace, and as it utilizes a hardware mechanism, no software patch can fix it.

The attack, appropriately called “Pacman,” works by “guessing” a pointer authentication code (PAC), a cryptographic signature that confirms that an app hasn’t been maliciously altered. This is done using speculative execution—a technique used by modern computer processors to speed up performance by speculatively guessing various lines of computation—to leak PAC verification results, while a hardware side-channel reveals whether or not the guess was correct.

What’s more, since there are only so many possible values for the PAC, the researchers found that it’s possible to try them all to find the right one.

It’s not obvious how to exploit this vulnerability in the wild, so I’m unsure how important this is. Also, I don’t know if it also applies to Apple’s new M2 chip.

Research paper. Another news article.

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Posted on June 15, 2022 at 6:05 AM • View Comments

Hacking Tesla’s Remote Key Cards

Interesting vulnerability in Tesla’s NFC key cards:

Martin Herfurt, a security researcher in Austria, quickly noticed something odd about the new feature: Not only did it allow the car to automatically start within 130 seconds of being unlocked with the NFC card, but it also put the car in a state to accept entirely new keys—with no authentication required and zero indication given by the in-car display.

“The authorization given in the 130-second interval is too general… [it’s] not only for drive,” Herfurt said in an online interview. “This timer has been introduced by Tesla…in order to make the use of the NFC card as a primary means of using the car more convenient. What should happen is that the car can be started and driven without the user having to use the key card a second time. The problem: within the 130-second period, not only the driving of the car is authorized, but also the [enrolling] of a new key.”

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Posted on June 14, 2022 at 7:19 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.