33C3: Memory Deduplication, The Hacker’s Friend

February 4, 2017 by Elliot Williams 11 Comments

At the 33rd annual Chaos Communications Congress, [Antonio Barresi] and [Erik Bosman] presented not one, not two, but three (3!!) great hacks that were all based on exploiting memory de-duplication in virtual machines. If you’re interested in security, you should definitely watch the talk, embedded below. And grab the slides too. (PDF)

Memory de-duplication is the forbidden fruit for large VM setups — obviously dangerous but so tempting. Imagine that you’re hosting VMs and you notice that many of the machines have the same things in memory at the same time. Maybe we’re all watching the same cat videos. They can save on global memory across the machines by simply storing one copy of the cat video and pointing to the shared memory block from each of the machines that uses it. Notionally separate machines are sharing memory. What could go wrong?

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Well, That Was Quick: Heng Lamp Duplicated

February 4, 2017 by Elliot Williams 20 Comments

That didn’t take long at all! We covered a pretty cool lamp with a novel magnetic switch mechanism, and [msraynsford] has his version laser cut, veneered, a video posted on YouTube (embedded below), and an Instructable written up before we’d even caught our breath.

For those who missed it, the original Heng lamp is a beautiful design with a unique take on a magnetic switch. As with the original, the secret sauce is a switch inside that’s physically held closed by the two magnets. It’s a pretty clever mechanism that looks magical to boot.

[msraynsford]’s version replaces the floating spheres with floating cylinders, which are easier to fabricate in layers on a laser cutter, but otherwise the copy is fairly true to the aesthetics of the original. Pretty sweet!
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Valentine’s Heart With Awesome Animations

February 3, 2017 by Elliot Williams 3 Comments

January has drawn to a close, and for many of you that means: “Oh no! Less than two weeks’ time until Valentine’s day.” But for us here at Hackaday, it means heart-themed blinky projects. Hooray!

[Dmitry Grinberg] has weighed in with his version of the classic heart-shaped LED ring. It’s hard to beat the BOM on this one: just a microcontroller, five resistors, and twenty LEDs. The rest is code, and optionally putting the name of your beloved into the copper layer. Everything is there for you to download.

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Graphene? Soybean!

February 3, 2017 by Elliot Williams 37 Comments

True graphene is a one-atom thick layer of carbon. It’s incredibly conductive, transparent, and of course thin. It’s one of those materials that, if it were only cheaper, would be used in everything from batteries to water filtration. Researchers from CSIRO in Australia have found a novel, dirt-cheap, and simple way to make graphene, and it’s hacker-friendly, for certain values of hacker.

The method is to take a sheet of polycrystalline nickel foil, spread a thin layer of soybean oil on it, and heat it up to 800° C for three minutes. It’s cooled off, slid off the foil, and it’s done. While 800° is a lot hotter than a standard toaster oven, their setup isn’t really all that much different. Notably lacking are things like esoteric gasses, partial vacuums, and the like. The nickel foil has some kind of catalytic role in the process — you should read the original if you’re more of a chemist than we are. Continue reading “Graphene? Soybean!” →

Yes/No Neural Interface Partly Works

February 2, 2017 by Elliot Williams 19 Comments

It sounds like something out of a sci-fi or horror movie: people suffering from complete locked-in state (CLIS) have lost all motor control, but their brains are otherwise functioning normally. This can result from spinal cord injuries or anyotrophic lateral sclerosis (ALS). Patients who are only partially locked in can often blink to signal yes or no. CLIS patients don’t even have this option. So researchers are trying to literally read their minds.

Neuroelectrical technologies, like the EEG, haven’t been successful so far, so the scientists took another tack: using near-infrared light to detect the oxygenation of blood in the forehead. The results are promising, but we’re not there yet. The system detected answers correctly during training sessions about 70% of the time, where the upper bound for random chance is around 65% — varying from trial to trial. This may not seem overwhelmingly significant, but repeating the question many times can help improve confidence in the answer, and these are people with no means of communicating with the outside world. Anything is better than nothing?

It’s noteworthy that the blood oxygen curves over time vary significantly from patient to patient, but seem roughly consistent within a single patient. Some people simply have patterns that are easier to read. You can see all the data in the paper.

They go into the methodology as well, which is not straightforward either. How would you design a test for a person who you can’t even tell if they are awake, for instance? They ask complementary questions (“Paris is the capital of France”, “Berlin is the capital of Germany”, “Paris is the capital of Germany”, and “Berlin is the capital of France”) to be absolutely sure they’re getting the classifications right.

It’s interesting science, and for a good cause: improving the quality of life for people who have lost all contact with their bodies. (Most of whom answered “yes” to the statement “I am happy.” Food for thought.)

Via Science-Based Medicine, and thanks to [gippgig] for the unintentional tip! Photo from the Wyss Center, one of the research institutes involved in the study.

No-Etch: The Proof In The Bluetooth Pudding

February 2, 2017 by Elliot Williams 40 Comments

In a previous episode of Hackaday, [Rich Olson] came up with a new no-etch circuit board fabrication method. And now, he’s put it to the test: building an nRF52 Bluetooth reference design, complete with video, embedded below.

The quick overview of [Rich]’s method: print out the circuit with a laser printer, bake a silver-containing glue onto the surface, repeat a few times to get thick traces, glue the paper to a substrate, and use low-temperature solder to put parts together. A potential drawback is the non-negligible resistance for the traces, but a lot of the time that doesn’t matter and the nRF52 reference design proves it.

The one problem here may be the trace antenna. [Rich] reports that it sends out a weaker-than-expected signal. Any RF design folks want to speculate wildly about the cause?

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33C3: Hunz Deconstructs The Amazon Dash Button

February 2, 2017 by Elliot Williams 22 Comments

The Amazon Dash button is now in its second hardware revision, and in a talk at the 33rd Chaos Communications Congress, [Hunz] not only tears it apart and illuminates the differences with the first version, but he also manages to reverse engineer it enough to get his own code running. This opens up a whole raft of possibilities that go beyond the simple “intercept the IP traffic” style hacks that we’ve seen.

Just getting into the Dash is a bit of work, so buy two: one to cut apart and locate the parts that you have to avoid next time. Once you get in, everything is tiny! There are a lot of 0201 SMD parts. Hidden underneath a plastic blob (acetone!) is an Atmel ATSAMG55, a 120 MHz ARM Cortex-M4 with FPU, and a beefy CPU all around. There is also a 2.4 GHz radio with a built-in IP stack that handles all the WiFi, with built-in TLS support. Other parts include a boost voltage converter, a BTLE chipset, an LED, a microphone, and some SPI flash.

The strangest part of the device is the sleep mode. The voltage regulator is turned on by user button press and held on using a GPIO pin on the CPU. Once the microcontroller lets go of the power supply, all power is off until the button is pressed again. It’s hard to use any less power when sleeping. Even so, the microcontroller monitors the battery voltage and presumably phones home when it gets low.
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