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Cardiac Biometric

MIT Technology Review is reporting about an infrared laser device that can identify people by their unique cardiac signature at a distance:

A new device, developed for the Pentagon after US Special Forces requested it, can identify people without seeing their face: instead it detects their unique cardiac signature with an infrared laser. While it works at 200 meters (219 yards), longer distances could be possible with a better laser. “I don’t want to say you could do it from space,” says Steward Remaly, of the Pentagon’s Combatting Terrorism Technical Support Office, “but longer ranges should be possible.”

Contact infrared sensors are often used to automatically record a patient’s pulse. They work by detecting the changes in reflection of infrared light caused by blood flow. By contrast, the new device, called Jetson, uses a technique known as laser vibrometry to detect the surface movement caused by the heartbeat. This works though typical clothing like a shirt and a jacket (though not thicker clothing such as a winter coat).

[…]

Remaly’s team then developed algorithms capable of extracting a cardiac signature from the laser signals. He claims that Jetson can achieve over 95% accuracy under good conditions, and this might be further improved. In practice, it’s likely that Jetson would be used alongside facial recognition or other identification methods.

Wenyao Xu of the State University of New York at Buffalo has also developed a remote cardiac sensor, although it works only up to 20 meters away and uses radar. He believes the cardiac approach is far more robust than facial recognition. “Compared with face, cardiac biometrics are more stable and can reach more than 98% accuracy,” he says.

I have my usual questions about false positives vs false negatives, how stable the biometric is over time, and whether it works better or worse against particular sub-populations. But interesting nonetheless.

Posted on July 8, 2019 at 12:38 PMView Comments

Applied Cryptography is Banned in Oregon Prisons

My Applied Cryptography is on a list of books banned in Oregon prisons. It’s not me—and it’s not cryptography—it’s that the prisons ban books that teach people to code. The subtitle is “Algorithms, Protocols, and Source Code in C”—and that’s the reason.

My more recent Cryptography Engineering is a much better book for prisoners, anyway.

Posted on July 5, 2019 at 1:52 PMView Comments

Research on Human Honesty

New research from Science: “Civic honesty around the globe“:

Abstract: Civic honesty is essential to social capital and economic development, but is often in conflict with material self-interest. We examine the trade-off between honesty and self-interest using field experiments in 355 cities spanning 40 countries around the globe. We turned in over 17,000 lost wallets with varying amounts of money at public and private institutions, and measured whether recipients contacted the owner to return the wallets. In virtually all countries citizens were more likely to return wallets that contained more money. Both non-experts and professional economists were unable to predict this result. Additional data suggest our main findings can be explained by a combination of altruistic concerns and an aversion to viewing oneself as a thief, which increase with the material benefits of dishonesty.

I am surprised, too.

Posted on July 5, 2019 at 6:15 AMView Comments

US Journalist Detained When Returning to US

Pretty horrible story of a US journalist who had his computer and phone searched at the border when returning to the US from Mexico.

After I gave him the password to my iPhone, Moncivias spent three hours reviewing hundreds of photos and videos and emails and calls and texts, including encrypted messages on WhatsApp, Signal, and Telegram. It was the digital equivalent of tossing someone’s house: opening cabinets, pulling out drawers, and overturning furniture in hopes of finding something—anything—illegal. He read my communications with friends, family, and loved ones. He went through my correspondence with colleagues, editors, and sources. He asked about the identities of people who have worked with me in war zones. He also went through my personal photos, which I resented. Consider everything on your phone right now. Nothing on mine was spared.

Pomeroy, meanwhile, searched my laptop. He browsed my emails and my internet history. He looked through financial spreadsheets and property records and business correspondence. He was able to see all the same photos and videos as Moncivias and then some, including photos I thought I had deleted.

The EFF has extensive information and advice about device searches at the US border, including a travel guide:

If you are a U.S. citizen, border agents cannot stop you from entering the country, even if you refuse to unlock your device, provide your device password, or disclose your social media information. However, agents may escalate the encounter if you refuse. For example, agents may seize your devices, ask you intrusive questions, search your bags more intensively, or increase by many hours the length of detention. If you are a lawful permanent resident, agents may raise complicated questions about your continued status as a resident. If you are a foreign visitor, agents may deny you entry.

The most important piece of advice is to think about this all beforehand, and plan accordingly.

Posted on July 4, 2019 at 6:38 AMView Comments

Digital License Plates

They’re a thing:

Developers say digital plates utilize “advanced telematics”—to collect tolls, pay for parking and send out Amber Alerts when a child is abducted. They also help recover stolen vehicles by changing the display to read “Stolen,” thereby alerting everyone within eyeshot.

This makes no sense to me. The numbers are static. License plates being low-tech are a feature, not a bug.

Posted on July 3, 2019 at 6:28 AMView Comments

Google Releases Basic Homomorphic Encryption Tool

Google has released an open-source cryptographic tool: Private Join and Compute. From a Wired article:

Private Join and Compute uses a 1970s methodology known as “commutative encryption” to allow data in the data sets to be encrypted with multiple keys, without it mattering which order the keys are used in. This is helpful for multiparty computation, where you need to apply and later peel away multiple layers of encryption without affecting the computations performed on the encrypted data. Crucially, Private Join and Compute also uses methods first developed in the ’90s that enable a system to combine two encrypted data sets, determine what they have in common, and then perform mathematical computations directly on this encrypted, unreadable data through a technique called homomorphic encryption.

True homomorphic encryption isn’t possible, and my guess is that it will never be feasible for most applications. But limited application tricks like this have been around for decades, and sometimes they’re useful.

Boing Boing article.

Posted on July 2, 2019 at 6:24 AMView Comments

Yubico Security Keys with a Crypto Flaw

Wow, is this an embarrassing bug:

Yubico is recalling a line of security keys used by the U.S. government due to a firmware flaw. The company issued a security advisory today that warned of an issue in YubiKey FIPS Series devices with firmware versions 4.4.2 and 4.4.4 that reduced the randomness of the cryptographic keys it generates. The security keys are used by thousands of federal employees on a daily basis, letting them securely log-on to their devices by issuing one-time passwords.

The problem in question occurs after the security key powers up. According to Yubico, a bug keeps “some predictable content” inside the device’s data buffer that could impact the randomness of the keys generated. Security keys with ECDSA signatures are in particular danger. A total of 80 of the 256 bits generated by the key remain static, meaning an attacker who gains access to several signatures could recreate the private key.

Boing Boing post.

EDITED TO ADD (6/12): From Microsoft TechNet Security Guidance blog (in 2014): “Why We’re Not Recommending ‘FIPS Mode’ Anymore.

Posted on July 1, 2019 at 5:55 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.