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How to Let Everyone Keep a Secret

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Someone calls you at work and says, “Don’t tell anyone, but…” If you are like most people, there are one or two people you will pass it along to with the same admonishment. In fact, they are probably repeating it from someone else, and you are on their list of two people. So for really big secrets, you need a way to spread the secret out so that no one has any real information about the secret, but a certain number of people together can decode it. As [neeaj] explains in a recent post about  Shamir’s Secret Sharing , [Adi Shamir] (the S in RSA encryption) devised a way to do this very well in 1979, and the core concept is very easy to understand. The explanation works with geometry. The equation for a line is y=mx+b, where m is the slope and b is the y-intercept (that is, where the line touches the y-axis when X is 0. An infinite number of lines cross the Y axis at, for example, 10. The line y=3x+10 does, and so does the line y=-1.41x+10. You can’t g...

Recycling Two XBox One Consoles into a 10 GB USB Flash Drive

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Amidst the ongoing RAM & storage apocalypses, Mad Max-esque scenes are unsurprisingly developing, with the eMMC recycling project by [Chase Fournier] from a pair of XBox One S (‘XBone’) mainboards being just one more example. These mainboards come equipped with a 5 GB eMMC chip installed, alongside 8 GB of DDR3. Removing the eMMC chips isn’t that complicated and after some reballing fun the chips were both installed on a carrier board with a Norelsys NS1081 controller IC. This provides a USB 3.0 interface and can connect to up to four SD or eMMC memories, with here just two channels used. Although the eMMC testing device didn’t seem too happy with either chip, after mounting them on the PCB the controller could be programmed and saw both eMMC packages for a grand total of 10 GB storage. Sequential read performance in CrystalDiskMark was about 140 MB/s while write performance was about 64 MB/s, which is zippy enough for smaller files. Not that you can sto...

Camping on Unconventional Watercraft

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The fjords of Norway are world famous for their beauty, but even though the word itself is Norwegian, there are fjords all over the world in areas that used to be covered in glaciers. One of these areas is the Pacific Northwest of North America, we herit’s actually possible to travel by boat from the Seattle area all the way into Alaska without going to the Pacific Ocean, and although plenty of people make this journey by boat, [Matt] is planning on doing this journey on a jet ski with a custom camper on the back . Normally a jet ski wouldn’t be the ideal platform for a multi-day on-boat adventure because of their size, but [Matt] found perhaps the largest jet ski ever made and he got a deal on it since it had previously been wrecked. Once he repaired the hull damage, he cut a sheet of plywood in half and put a hinge in the middle so it can unfold over the top of the jet ski but fold it away when he’s traveling. With the basic concept in place he took it right out on ...

Attack of the Atomic Oxygen

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While designing anything for operation in space has its challenges, there is at least one thing that is more of a problem for objects in Earth orbit than for deep-space probes: atomic oxygen. We like oxygen because we need it to live, but it is also highly reactive as a single atom. Luckily, on Earth, most of what we breathe is O 2 . [Space Daily] talks about the challenges of the International Space Station dealing with the “space weather” of atomic oxygen in low Earth orbit . Part of the problem is that even when we know better, we tend to think of the atmosphere coming to an abrupt end and space being a hard vacuum. But in reality, the atmosphere gradually dissipates, and at “only” 400 km above the Earth, the Space Station is really flying through a very thin atmosphere. To compound the problem, this is above the ozone layer, so the Sun’s UV light rips O 2 into single oxygen atoms. Over time, these free oxygen atoms can affect many parts of a spacecra...

Linux Distributions and Who is Responsible For the Software

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The topic of downstream and upstream is an important one in the Linux ecosystem, where from one base distribution you can go many layers of distros deep before even looking at all the other base distributions. Within that veritable jungle you get questions about who is responsible for packaging software, where to report bugs found with a specific application, as well as what ‘LTS’ truly means in a consumer context. These and other points are raised in a recent video by [Brodie Robertson], with many examples of things going tragically wrong. There’s a good argument to be made that ultimately it is the distro that is responsible for the software that they provide via their repositories. As [Brodie] shows in the video, there are a few cases where an ‘LTS’ distro uses an old version of some software that contains a bug that has been fixed a while ago, so reporting it to the developer is rather pointless, while the distro maintainers should fix it with backpor...

Autopsy of a Failed Vintage Carbon Resistor

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Detail of the lead connecting to the inner carbon-filled tube. (Credit: CuriousMarc) Although resistors are hardly among the most exciting components, they are arguably one of the most important ones, as anyone who has done any amount of circuit design and debugging can attest to. So too with a single carbon resistor in a vintage Metrix oscilloscope that [CuriousMarc] recently repaired. After recapping the board there was still a major issue that got traced down to said resistor. After replacing it with a fresh resistor obviously this meant doing an autopsy to see why the old resistor had failed . The 20 kOhm-rated resistor looked fine on the outside, with no obvious damage or discoloration, but it measured around 0.843 MOhm. To get to the insides [CuriousMarc] asked his friend [TubeTime] on how to proceed. The answer here was sandpaper and a lot of patience, and thus the experiment to see how much sanding it takes to get to the core of a fairly big resistor commenced. Ultimately th...

A Clock Inspired by Failed Cognitive Tests

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One simple screening tool for cognitive impairment is the clock-drawing test (CDT): the patient is provided with a printed circle and asked to draw a clock face with the hands pointing to a certain time. Depending on how the clock is drawn, this could indicate a variety of different disorders, particularly dementia, with a particular deformity in the drawing sometimes pointing to a specific issue. These failed tests inspired [John Silvia] to create a clock with a unique, disordered face. The numerals in this clock face are placed exclusively along the right half of the clock (in the test, this can be a sign of damage to the right parietal lobe, or of executive dysfunction caused by dementia), and out of order. The hour hand is controlled by a servo motor, and the minute hand is mounted on a separate, commercially-purchased clock mechanism on the left-hand side of the face. The frame for the clock and the face are 3D-printed, and the servo motor is controlled by an ESP32-C3 with an ...