Most people’s personal experience with seismographs begins and ends with simple childhood science experiments. Watching a pendulum make erratic marks on a piece of paper while your classmates banged on the table gave you an idea on how the device worked, and there’s an excellent chance that’s the last time you gave the concept much thought. Even among hackers, whose gear in general tends to be more technologically equipped than the norm, you’re unlikely to find a dedicated seismograph up and running.
But that’s not because the core technology is hard to come by or particularly expensive. In fact, one could say with almost absolute certainty that if you aren’t actively reading these words on a device with a sensitive accelerometer onboard, you have one (or perhaps several) within arm’s reach. Modern smartphones, tablets, and even some laptops, now pack in sensors that could easily be pushed into service as broad strokes seismometers; they just need the software to collect and analyze the data.
Or at least, they did. By the time you read this article, Google will have already started rolling out an update to Android devices which will allow them to use their onboard sensors to detect possible earthquakes. With literally billions of compatible devices in operation all over the planet, this will easily become the largest distributed sensor network of its type ever put into operation. But that doesn’t mean you’re going to be getting a notification on your phone to duck and cover anytime soon.
At any given time I’m likely to have multiple projects in-flight, by which of course I mean in various stages of neglect. My current big project is one where I finally feel like I have a chance to use some materials with real hacker street cred, like T-slot extruded aluminum profiles. We’ve all seen the stuff, the “Industrial Erector Set” as 80/20 likes to call their version of it. And we’ve all seen the cool projects made with it, from CNC machines to trade show displays, and in these pandemic times, even occasionally as sneeze guards in retail shops.
Aluminum T-slot profiles are wonderful to work with — strong, lightweight, easily connected with a wide range of fasteners, and infinitely configurable and reconfigurable as needs change. It’s not cheap by any means, but when you factor in the fabrication time saved, it may well be a net benefit to spec the stuff for a project. Still, with the projected hit to my wallet, I’ve been looking for more affordable alternatives.
My exploration led me into the bewilderingly rich world of aluminum extrusions. Even excluding mundane items like beer and soda cans, you’re probably surrounded by extruded aluminum products right now. Everything from computer heatsinks to window frames to the parts that make up screen doors are made from extruded aluminum. So how exactly is this ubiquitous stuff made?
Any modern computer with an x86 processor, whether it’s Intel or AMD, is a lost cause for software freedom and privacy. We harp on this a lot, but it’s worth repeating that it’s nearly impossible to get free, open-source firmware to run on them thanks to the Intel Management Engine (IME) and the AMD Platform Security Processor (PSP). Without libre firmware there’s no way to trust anything else, even if your operating system is completely open-source.
The IME or PSP have access to memory, storage, and the network stack even if the computer is shut down, and even after the computer boots they run at such a low level that the operating system can’t be aware of what they’re really doing. Luckily, there’s a dark horse in the race in the personal computing world that gives us some hope that one day there will be an x86 competitor that allows their users to have a free firmware that they can trust. ARM processors, which have been steadily increasing their user share for years but are seeing a surge of interest since the recent announcement by Apple, are poised to take over the personal computing world and hopefully allow us some relevant, modern options for those concerned with freedom and privacy. But in the real world of ARM processors the road ahead will decidedly long, windy, and forked.
Even ignoring tedious nitpicks that the distinction between RISC vs CISC is more blurred now than it was “back in the day”, RISC machines like ARM have a natural leg up on the x86 CISC machines built by Intel and AMD. These RISC machines use fewer instructions and perform with much more thermal efficiency than their x86 competitors. They can often be passively cooled, avoiding need to be actively cooled, unlike many AMD/Intel machines that often have noisy or bulky fans. But for me, the most interesting advantage is the ability to run ARM machines without the proprietary firmware present with x86 chips.
As the world grapples with the spectre of the so-called “hockey stick” graph of climate change, there have been a variety of solutions proposed to the problem of carbon emissions from sectors such as transport which have become inseparable from the maintenance of 21st century life. Sometimes these are blue-sky ideas that may just be a little bit barmy, while other times they make you stop and think: “That could just work!”.
Siemens and Scania are justifiably proud of their electrified stretch of autobahn and electric trucks in Germany.
One thing that should be obvious to all is that moving our long-distance freight around by means of an individual fossil-fuel-powered diesel engine for every 38 tonne or so freight container may be convenient, but it is hardly either fuel-efficient or environmentally friendly The most efficient diesel engines on the road are said to have a 43% efficiency, and when hauling an single load they take none of the economies of scale afforded to the diesel engines that haul for example a freight train. Similarly they spread any pollution they emit across the entirety of their route, and yet again fail to benefit from the economies of scale present in for example a power station exhaust scrubber. However much I have a weakness for the sight of a big rig at full stretch, even I have to admit that its day has passed.
The battery technology being pursued for passenger cars is a tempting alternative, as we’ve seen with Tesla Semi. But for all its technology that vehicle still walks the knife-edge between the gain in cost-effectiveness versus the cost of hauling around enough batteries to transport that quantity of freight. Against that the overhead wire truck seems to offer the best of both worlds, the lightness and easy refueling of a diesel versus the lack of emissions from an electric. In the idealised world of a brochure it runs on renewable wind, sun, and water power, so all our problems are solved, right? But does it really stack up?
The crown jewels of the Earth’s mountain ranges, the Himalayas, are unsurpassed in their beauty, their height, and their deadly attraction to adventurers, both professional and amateur. The gem of the Himalayas is, of course, Mount Everest, known as Sagarmatha to the Nepalis and Chomolungma to the Tibetans. At 8,848 meters (29,029 ft) — or more; it’s a geologically young mountain that’s still being thrust upward by tectonic activity — it’s a place so forbidding that as far as we know the summit was never visited until 1953, despite at least 30 years of previous attempts, many of which resulted in death.
The conquest of Everest remains a bucket list challenge for many adventurers, and despite advances in technology that have made the peak accessible to more people — or perhaps because of that — more than 300 corpses litter the mountain, testament to what can happen when you take the power of Mother Nature for granted.
To get better data on the goings-on at the Roof of the World, an expedition recently sought to install five weather stations across various points on the route up Mount Everest, including one at its very peak. The plan was challenging, both from a mountaineering perspective and in terms of the engineering required to build something that would be able to withstand some of the worst conditions on the planet, and to send valuable data back reliably. It didn’t all go exactly to plan, but it’s still a great story about the intersection of science and engineering.
To understand this security flaw, or group of security flaws, we first need to know what wireless coexistence mechanisms are. Modern devices can support cellular and non-cellular wireless communications standards at the same time (LTE, WiFi, Bluetooth). Given the desired miniaturization of our devices, the different subsystems that support these communication technologies must reside in very close physical proximity within the device (in-device coexistence). The resulting high level of reciprocal leakage can at times cause considerable interference.
There are several scenarios where interference can occur, the main ones are:
Two radio systems occupy neighboring frequencies and carrier leakage occurs
The harmonics of one transmitter fall on frequencies used by another system
Two radio systems share the same frequencies
To tackle these kind of problems, manufacturers had to implement strategies so that the devices wireless chips can coexist (sometimes even sharing the same antenna) and reduce interference to a minimum. They are called coexistence mechanisms and enable high-performance communication on intersecting frequency bands and thus, they are essential to any modern mobile device. Despite open solutions exist, such as the Mobile Wireless Standards, the manufacturers usually implement proprietary solutions.
Spectra
Spectra is a new attack class demonstrated in this DEF CON talk, which is focused on Broadcom and Cypress WiFi/Bluetooth combo chips. On a combo chip, WiFi and Bluetooth run on separate processing cores and coexistence information is directly exchanged between cores using the Serial Enhanced Coexistence Interface (SECI) and does not go through the underlying operating system.
Spectra class attacks exploit flaws in the interfaces between wireless cores in which one core can achieve denial of service (DoS), information disclosure and even code execution on another core. The reasoning here is, from an attacker perspective, to leverage a Bluetooth subsystem remote code execution (RCE) to perform WiFi RCE and maybe even LTE RCE. Keep in mind that this remote code execution is happening in these CPU core subsystems, and so can be completely invisible to the main device CPU and OS.
Join me below where the talk is embedded and where I will also dig into the denial of service, information disclosure, and code execution topics of the Spectra attack.
How cool would it be if there was a material that couldn’t be cut or drilled into? You could make the baddest bike lock, the toughest-toed work boots, or the most secure door. Really, the list of possibilities just goes on and on.
Proteus chews through an angle grinder disc in seconds.
The material is made of aluminium foam that’s embedded with a bunch of small ceramic spheres. It works by inducing retaliatory vibrations into the cutting tools, which turns the tools’ force back on themselves and quickly dulls their edges.
The creators have named the material Proteus after the elusive and shape-shifting prophet of Greek mythology who would only share his visions of the future with those who could get their arms around him and keep him still. It sounds like this material could give Proteus a run for his money.
The ceramic spheres themselves aren’t indestructible, but they’re not supposed to be. Abrading the spheres only makes Proteus stronger. As the cutting tool contacts them, they’re crushed into dust that fills the voids in the aluminium foam, strengthening the material’s destructive vibratory effect. The physical inspiration for Proteus comes from protective hierarchical structures in nature, like the impact-resistant rind of grapefruit and the tendency of abalone shells to resist fracture under the impact of shark teeth.
How It’s Made
Proteus recipe in pictures.
At this point, Proteus is a proof of concept. Adjustments would likely have to be made before it can be produced at any type of scale. Even so, the recipe seems pretty straightforward. First, an aluminium alloy powder is mixed with a foaming agent. Then the mixture is cold compacted in a compressor and extruded in dense rods. The rods are cut down to size and then arranged along with the ceramic spheres in a layered grid, like a metallurgical lasagna.
The grid is spot-welded into a steel box and then put into a furnace for 15-20 minutes. Inside the furnace, the foaming agent releases hydrogen gas, which introduces voids into the aluminium foam and gives it a cellular structure.
Effects of cutting into a cylinder of Proteus with an angle grinder.
According to their paper, the researchers tried to penetrate the material with an angle grinder, a water jet cutter, and a drill. Of these, the drill has the best chance of getting through because the small point of contact can find gaps more easily, so it’s less likely to hit a ceramic sphere. The researchers also made cylindrical samples without steel cladding which they used to test the compressive strength and prove Proteus’ utility as a structural material for beams and columns. It didn’t fare well initially, but became less compressible as the foam matrix collapsed.
The creation process lends some leeway for customization, because the porosity of the aluminium foam can be varied by changing the bake time. As for the drill bit problem, tightening up security is as easy as adjusting the size and/or density of the ceramic spheres.
In the video after the break, you can watch a chunk of Proteus eat up an angle grinder disc in under a minute. Some may argue about the tool wielder’s technique, but we think there’s something to be said for any material that can destroy a cutting disc that fast. They don’t claim that Proteus is completely impenetrable, but it does look impressive. We wish they would have tried more cutting tools like a gas torch, or experimented with other destructive techniques, like plastic explosives, but we suppose that research budgets only go so far.
