Magnets Are Bad For Hardware Again

If you were around tech in the bad old days, magnets could be really bad news. They were fine on the fridge, no problem at all. Put one near a floppy disk, or a hard drive, or even a computer monitor, though, and you were in for some pain. You’d lose data, possibly permanently destroy a disk or drive, or you’d get ugly smeary rainbow effects all over your screen.

The solid state revolution has eliminated a lot of these problems. We all use SSDs, flash drives, and LCD monitors now, all of which care a lot less about flirting with magnets. However, the same can’t be said about all our modern hardware, for a magnet could cause your smartphone some major grief indeed.

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Spy Tech: A Quiet Radio For Spies

Normally, when you think of a radio transmitter, you want the strongest signal and range. But if your radio operator is secretly operating as a spy, broadcasting their position isn’t a feature; it is a liability. This fact didn’t escape World War II radio designers.

In late 1942, the British realized they needed a way for Special Operation Executive agents, resistance members, and other friendly forces to communicate with an aircraft without attracting undue attention. Two engineers from the Royal Corps of Signals developed a pair of transceivers — the S-Phone — operating around 380 MHz just for this purpose. Frequencies this high were unusual at the time, which further deterred enemy detection.

The output power was below 200 mW, and the ground equipment consisted of a dipole strapped to the operator. No transistors, so with rechargable batteries, the rig weighed about fifteen pounds and reused some parts of a paratrooper radio, Wireless Set Number 37. The other side of the connection was installed in an airplane.

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Between-Device Sharing Still Sucks

Once upon a time, computing was simple. You had files on a floppy disk. If you wanted to take them to a different computer, you ejected the disk from one machine and put it in another. It wasn’t fast, but it was easy and intuitive. Besides, you probably only had one computer of your own, anyway.

Life has since gotten a lot more complex. You’ve got a desktop, a laptop, a work laptop, your personal and business phones, and a smart watch to boot. You live amongst a swirling maelstrom of terabytes of data. Despite all the technical advances that got you here, it’s still a pain to get a file from one device to another, even when they’re sitting on the same desk. Why?!

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How Pulse Oximetry Figures Out Your Blood Oxygen Levels

If you’ve ever had a medical team investigating cardiac issues, you’ve probably had a bunch of electrodes stuck all over your chest and been hooked up to an electrocardiogram. This is the gold standard when it comes to understanding electrical activity in the heart and can diagnose a great many conditions. However, sometimes doctors just need the basic information—your pulse rate, and whether or not there’s actually any oxygen in your blood.

Thankfully, there’s a cheap and simple device that can offer that exact information. It’s the pulse oximeter, and it’s a key piece of equipment that’s just about vital for monitoring vitals. Let’s learn how it works!

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How Search Engines Enabled Finding Needles In A WWW-Sized Haystack

When the World Wide Web surged into existence during the 1990s, we were introduced to the problem of how to actually find something in this ever-ballooning construction zone that easily outpaced even the fastest post-WW2 urban sprawl. Although domain names provided a way to find servers using DNS rather than having to mash in IP addresses, you still somehow had to know the relevant URL.

A range of solutions were thought up over time, ranging from printed Yellow Pages type guides, to online curated lists of resources, as well as things like web rings where one website would link to a relevant similar website. This was the time when word-of-mouth was also very relevant, with people proudly announcing their own website on Geocities or other hosting service.

Search engines already existed long before the WWW became the hot new thing during the 1990s, but it was the WWW that would really push them to their limits. As anyone who used search engines for the WWW can attest, they had many issues. Often you’d end up using multiple search engines to find something, and despite fierce competition between web search engines to become the starting page for their browser, actually finding things on the WWW remained a tough problem.

Since a web search engine ‘just’ has to index the WWW and match a search query against the results, why was this such a hard problem that persisted until Google apparently cracked the code?

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How To Make Steel That Breathes

There are plenty of porous materials out there that we’re all readily familiar with. Fabrics and wood are great examples, allowing liquids or gases to pass through to a certain degree—a property which is useful or problematic depending on the application.

Metals, however, are not something we would readily consider to be porous. They are solid, unyielding, and impermeable. However, with the right techniques, it is possible to produce so-called “breathable” steel, which has particularly interesting applications in the molding industry.

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This Week In Security: Android Exposes ADB, ShinyHunters Get Paid, Robot Dogs, And More

Google has patched an Android ADB bug in the May security patch set. If you have a Pixel phone you should already have the patches, and most other major manufacturers should be close behind. Unfortunately, the biggest risk from this patch will be to the vendors who are also the least likely to release timely – or any – security updates.

ADB, the Android Debug Bridge, is the main tool for installing apps during development and debugging apps while they’re running. It can also be used to side-load apps from a PC. While most normal users are unlikely to ever enable it, developers typically do and some power users might when jailbreaking a device or setting parameters not exposed in the Android UI. Debugging can be done locally via USB, or optionally over the network. To protect the device, the user must unlock the Android device and authorize each new debug agent.

Covered by Risky.Biz, a bug introduced in 2020, and present in every Android release since, allowed bypassing authorization entirely if network debugging was enabled and at least one connection had been made to the ADB service in the past. This happens because ADB compares the certificate of the incoming debug connection with the list of saved certificates. If the certificate type does not match — for instance supplying an Ed25519 certificate instead of a RSA certificate — ADB has been incorrectly handling the error code, and allowing the connection.

In most programming languages, false is considered zero, and true is considered anything not zero. The certificate API returns a 1 for a valid match, a zero for an invalid match, and a negative-one for a type mismatch. Negative one is not zero, so when treated as a boolean value, it becomes true.

To exploit the bug, ADB must be enabled in wireless mode, and there must be at least one trusted device in the ADB configuration. For the average user this is an unlikely combination, but for developers, the time to update is now.

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