The British Government Is Coming For Your Privacy

July 30, 2023 by Jenny List 77 Comments

The list of bad legislation relating to the topic of encryption and privacy is long and inglorious. Usually, these legislative stinkers only affect those unfortunate enough to live in the country that passed them. Still, one upcoming law from the British government should have us all concerned. The Online Safety Bill started as the usual think-of-the-children stuff, but as the EFF notes, some of its proposed powers have the potential to undermine encryption worldwide.

At issue is the proposal that services with strong encryption incorporate government-sanctioned backdoors to give the spooks free rein to snoop on communications. We imagine that this will be of significant interest to some of the world’s less savoury regimes, a club we can’t honestly say the current UK government doesn’t seem hell-bent on joining. The Bill has had a tumultuous passage through the Lords, the UK upper house, but PM Rishi Sunak’s administration has proved unbending.

If there’s a silver lining to this legislative train wreck, it’s that many of the global tech companies are likely to pull their products from the UK market rather than comply. We understand that UK lawmakers are partial to encrypted online messaging platforms. Thus, there will be poetic justice in their voting once more for a disastrous bill with the unintended consequence of taking away something they rely on.

Header image: DaniKauf, CC BY-SA 3.0.

How To Survive A Wet Bulb Event

July 27, 2023 by Lewin Day 268 Comments

Territories across the northern hemisphere are suffering through record-breaking heatwaves this summer. Climate scientists are publishing graphs with red lines jagging dangerously upwards as unprecedented numbers pour in. Residents of the southern hemisphere watch on, wondering what the coming hot season will bring.

2023 is hinting at a very real climate change that we can’t ignore. As the mercury rises to new heights, it’s time to educate yourself on the very real dangers of a wet bulb event. Scientists predict that these deadly weather conditions could soon strike in the hottest parts of the world. What you learn here could end up saving your life one day.

Hot Bodies

The body has methods of maintaining a set temperature. *Credit: Wikimedia Commons, CNX OpenStax, CC BY-SA 4.0*

To understand the danger of a wet bulb event, we must first understand how our bodies work. The human body likes to maintain its temperature at approximately 37 °C (98.6 °F). That temperature can drift slightly, and the body itself will sometimes move its temperature setpoint higher to tackle infection, for example. The body is a delicate thing, however, and a body temperature above 40 °C (104 °F) can become life threatening. Seizures, organ failures, and unconsciousness are common symptoms of an overheating human. Death is a near-certainty if the body’s temperature reaches 44 °C (112 °F), though in one rare case, a patient in a coma survived a body temperature of 46.5 °C (115.7 °F).

Thankfully, the body has a host of automated systems for maintaining its temperature at its chosen set point. Blood flow can be controlled across the body, and we instinctively seek to shed clothes in the heat and cover ourselves in the cold. However, the bare naked fact is that one system is most crucial to our body’s ability to cool itself. The perspiration system is vital, as it uses sweat to cool our body via evaporation. Water is a hugely effective coolant in this way, with beads of sweat soaking up huge amounts of heat from our skin as they make the phase change from liquid to vapor.

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ChatGPT, The Worst Summer Intern Ever

July 26, 2023 by Dan Maloney 71 Comments

Back when I used to work in the pharma industry, I had the opportunity to hire summer interns. This was a long time ago, long enough that the fresh-faced college students who applied for the gig are probably now creeping up to retirement age. The idea, as I understood it, was to get someone to help me with my project, which at the time was standing up a distributed data capture system with a large number of nodes all running custom software that I wrote, reporting back to a central server running more of my code. It was more work than I could manage on my own, so management thought they’d take mercy on me and get me some help.

The experience didn’t turn out quite like I expected. The interns were both great kids, very smart, and I learned a lot from them. But two months is a very tight timeframe, and getting them up to speed took up most of that time. Add in the fact that they were expected to do a presentation on their specific project at the end of the summer, and the whole thing ended up being a lot more work for me than if I had just done the whole project myself.

I thought about my brief experience with interns recently with a project I needed a little help on. It’s nothing that hiring anyone would make sense to do, but still, having someone to outsource specific jobs to would be a blessing, especially now that it’s summer and there’s so much else to do. But this is the future, and the expertise and the combined wisdom of the Internet are but a few keystrokes away, right? Well, maybe, but as you’ll see, even the power of large language models has its limit, and trying to loop ChatGPT in as a low-effort summer intern leaves a lot to be desired.

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PCIe For Hackers: Our M.2 Card Is Done

July 25, 2023 by Arya Voronova 18 Comments

We’ve started designing a PCIe card last week, an adapter from M.2 E-key to E-key, that adds an extra link to the E-key slot it carries – useful for fully utilizing a few rare but fancy E-key cards. By now, the schematic is done, the component placement has been figured out, and we only need to route the differential pairs – should be simple, right? Buckle up.

Getting Diffpairs Done

PCIe needs TX pairs connected to RX on another end, like UART – and this is non-negotiable. Connectors will use host-side naming, and vice-versa. As the diagram demonstrates, we connect the socket’s TX to chip’s RX and vice-versa; if we ever get confused, the laptop schematic is there to help us make things clear. To sum up, we only need to flip the names on the link coming to the PCIe switch, since the PCIe switch acts as a device on the card; the two links from the switch go to the E-key socket, and for that socket’s purposes, the PCIe switch acts as a host.

While initially routing this board, I absolutely forgot about one more important thing for PCIe – series capacitors on every data pair, on the host TX side of the link. We need three capacitor pairs here – on TX of the PCIe switch uplink, and two pairs on TX side of the switch – again, naming is host-side. I only remembered this after having finished routing all the diffpairs, and, after a bit of deliberation, I decided that this is my chance to try 0201 capacitors. For that, I took the footprints from [Christoph]‘s wonderful project, called “Effect of moon phase on tombstoning” – with such a name, these footprints have got to be good.

We’ve talked about differential pair calculations before in one of the PCIe articles, and there was a demo video too! That said, let’s repeat the calculations on this one – I’ll show how to get from “PCB fab website information” to “proper width and clearance diffpairs”, with a few fun shortcuts. Our setup is, once again, having signals on outer layers, referenced to the ground layer right below them. I, sadly, don’t yet understand how to calculate differential impedance for signal layers sandwiched between two ground planes, which is to say – if there’s any commenters willing to share this knowledge, I’d appreciate your input tremendously! For now, I don’t see that there’d be a tangible benefit to such an arrangement, anyway.

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DisplayPort: Tapping The Altmode

July 24, 2023 by Arya Voronova 11 Comments

Really, the most modern implementation of DisplayPort is the USB-C DisplayPort altmode, synonymous with “video over USB-C”, and we’d miss out if I were to skip it. Incidentally, our last two articles about talking USB-PD have given a few people a cool new toy to play with – people have commented on the articles, reached out to me for debugging help, and I’ve even seen people build the FUSB302B into their projects! Hot on the heels of that achievement, let’s reach further and conquer one more USB-C feature – one that isn’t yet openly available for us to hack on, even though it deserves to be.

For our long-time readers, it’s no surprise to see mundane capabilities denied to hackers. By now, we all know that many laptops and phones let you get a DisplayPort connection out of a USB-C port. Given that the USB-C specifications are openly available, and we’ve previously implemented a PD sink using those specifications, you’d expect that we could do DisplayPort with the same ease. Yet, the DisplayPort altmode specification is behind a VESA membership paywall, with a hefty pricetag – a practice of theirs that has been widely criticized, counter to their purpose as a standards organization and having resulted in some of their standards failing.

Not to worry, however – we can easily find an assortment of PDFs giving a high-level overview and some details of the DisplayPort altmode, and here’s my favorite! I also have a device running MicroPython with a FUSB302 chip connected, and a few DisplayPort altmode devices of mine that I can disassemble. This, turns out, is more than enough for us to reverse-engineer our way into an open-source DisplayPort altmode library!

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Weather In Wartime: The Importance Of British Meteorology In WWII

July 24, 2023 by Donald Papp 10 Comments

Weather can have a significant impact on transport and operations of all kinds, especially those at sea or in the air. This makes it a deeply important field of study, particularly in wartime. If you’re at all curious about how this kind of information was gathered and handled in the days before satellites and computer models, this write-up on WWII meteorology is sure to pique your interest.

Weather conditions were valuable data, and weather *forecasts* even more so. Both required data, which relied on human operators for instruments to be read and their readings transmitted.

The main method of learning weather conditions over the oceans is to persuade merchant ships to report their observations regularly. This is true even today, but these days we also have the benefit of things like satellite technology. Back in the mid-1900s there was no such thing, and the outbreak of WWII (including the classification of weather data as secret information due to its value) meant that new solutions were needed.

The aircraft of the Royal Air Force (RAF) were particularly in need of accurate data, and there was little to no understanding of the upper atmosphere at the time. Eventually, aircraft flew regular 10-hour sorties, logging detailed readings that served to provide data about weather conditions across the Atlantic. Readings were logged, encoded with one-time pad (OTP) encryption, then radioed back to base where charts would be created and updated every few hours.

The value of accurate data and precise understanding of conditions and how they could change was grimly illustrated in a disaster called the Night of the Big Wind (March 24-25, 1944). Forecasts predicted winds no stronger than 45 mph, but Allied bombers sent to Berlin were torn apart when they encountered winds in excess of 120 mph, leading to the loss of 72 aircraft.

The types of data recorded to monitor and model weather are nearly identical to those in modern weather stations. The main difference is that instruments used to be read and monitored by human beings, whereas today we can rely more on electronic readings and transmission that need no human intervention.

Ask Hackaday: What’s Linux Anyway?

July 21, 2023 by Al Williams 55 Comments

Any time we mention Linux, it is a fair bet we will get a few comments from people unhappy that we didn’t refer to it as GNU/Linux or with some other appellation. To be fair, they aren’t wrong. Linux is a kernel. Much of what we think of as a Linux desktop OS is really from other sources, including, but not limited to, GNU. We thought about this after reading a report from [The Register] that Linux has nearly half of the desktop OS Linux market. Wait, what?

If you are like us, you probably think that’s a typo. It isn’t. But the more you think about it, the less sense it makes. You know that half of the world’s desktops don’t run Linux. But maybe they mean Unix? Nope. So how can Linux have almost half of the Linux market? That’s like saying nearly half of Hackaday readers read Hackaday, right?

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