How To Reverse Engineer Silicon

January 16, 2018 by 19 Comments

A few semesters back, [Jordan] was in an Intro to Hardware Security course at CMU. The final project was open ended, and where some students chose projects like implementing a crypto algorithm or designing something on an FPGA, [Jordan] decided to do something a little more ambitious. He wanted to decapsulate and reverse engineer an IC. No, this isn’t taking a peek at billions of transistors — [Jordan] chose a 74-series Quad XOR for this project — but it does show what goes into reverse engineering silicon, and how even simple chips can be maddeningly confusing.

The first step to reverse engineering a chip is decapsulation, and for this [Jordan] had two options. He could drop acid, or he could attack a ceramic package with an endmill. While hot nitric acid is effective and fun, it is a bit scary, so [Jordan] mounted a few chips in a 3D printed holder wedged in the vice on his mill. By slowly bringing the Z axis down a few thou at a time, he was able to find the tiny 1 mm square bit of silicon embedded in this chip. With the help of a grad student and the cleanroom, this square of sand was imaged with a very nice microscope.

Now that [Jordan] had an image of the silicon itself, he had to reverse engineer the chip. You might think that with less than a dozen transistors in there, designing an XOR out of transistors is something anyone with a bit of Minecraft experience can do. This line of thinking proved to be a trap. Technically, this wasn’t an XOR gate. It was a transmission gate XNOR gate with a big inverter on the output. Logically, it’s the same, but when it comes to silicon fabrication, the transmission gate XNORs aren’t able to sink or source a lot of current. By designing the chip as an XNOR with an inverter, the chip designers were able to design a simple chip that could still meet the spec.

While [Jordan] managed to reverse engineer the chip, this was quite possibly the simplest chip he could reverse engineer. The Quad XOR is just the same silicon repeated four times, anyway. This is the baseline for all efforts to reverse engineer silicon, and there were still a few confusing traps.

Review: LinkSprite Mini CNC

January 16, 2018 by 106 Comments

It’s a great time to be a hobbyist. No matter how you feel about the Arduino/Raspberry Pi effect, the influx of general enthusiasm and demand it has created translates to better availability of components, a broader community, and loads of freely available knowledge. When people have access to knowledge and ideas, great things can happen. Tools that were once restricted to industrial use become open source, and the price of entry-level versions goes into a nosedive.

As we’ve seen over the last several years, the price of cheap 3D printers keeps falling while the bar of quality keeps rising. It’s happening with laser cutters and carving tools, too. Strolling through Microcenter a few weeks ago, I spotted a new toy on the back wall next to the 3D printers. It was LinkSprite’s desktop mini CNC. They didn’t have one out on display, but there were two of them in boxes on the shelf. And boy, those boxes were small. Laughably small. I wondered, could this adorable machine really be any good? To some, the $200 price tag suggests otherwise. To me, the price tag made it justifiable, especially considering that the next price point for a hobby CNC mill is at least twice as much. I took my phone out and stood there frantically looking for reviews, documentation, anything that was available. It seemed that the general, if sparse consensus is that this thing isn’t a total waste of money. Oh, and there’s a wiki.

According to LinkSprite’s wiki, this little machine will engrave wood, plastic, acrylic, PVC, and PCBs. It will specifically not engrave metal (PCB copper notwithstanding). I’m a bit leery of the chemicals used in the PCB etching process, so the idea of engraving them instead was especially tempting. I pulled the trigger.

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Remember Your Birthday For Fifty Years

January 16, 2018 by 18 Comments

Our Coin Cell Challenge competition has turned up some amazing entries, things that we wouldn’t have thought possible from such meagre power sources. Take [Vishnu M Aiea]’s entry for instance, a device which he claims can light up as a birthday reminder every year for up to fifty years.

At its heart is a modified Arduino Nano clone that draws a measured 608 nA from a CR2450N. From the specification of the cell he has calculated the 50 year maximum figure, as well as a possible 29 years for a CR2032 and 64 years for a CR2477. He does however note that this does not take self-discharge into account, but you can probably afford a new battery in a decade or so.

The Arduino clone carefully selected for its “P” version low-power processor has had its serial bridge IC removed to achieve this power consumption, as well as a voltage regulator and some discrete components. Interestingly he notes that the ATMega168P is even more frugal than its 328 cousin, so he’s used the former chip. A selection of internal flags are set for minimal power consumption, and the internal oscillator is selected to use as low a clock speed as possible. There is an Intersil ISL1208 low power RTC chip mounted on a piece of stripboard to provide the timing, and of course an LED to provide the essential birthday alert.

When the LED lights for the big day there’s always the hope you’ll receive another coin cell, this time powering an edge-lit musical birthday card.

 

Win Big Prizes With Repairs You Can Print

January 16, 2018 by 58 Comments

Another month, another contest, and this time we’re looking for the best 3D printed repairs you’ve built.

The Repairs You Can Print Contest on Hackaday.io is a challenge to show off the real reason you bought a 3D printer. We want to see replacement parts, improved functionality, or a tool or jig that made a tough repair a snap. Think of this as the opposite of printing low poly Pokemon or Fallout armor. This is a contest to demonstrate the most utilitarian uses of a 3D printer. Whether you fixed your refrigerator, luggage, jet engine, vacuum cleaner, bike headlight, or anything else, we want to see how you did it!

The top twenty projects in the Repairs You Can Print contest will be rewarded with $100 in Tindie credit. That’s a Benjamin to spend on parts, upgrades, and components to take your next project to the next level!

Students and Organizations Can Win Big

The Best Student and Best Organization will win a Prusa i3 MK3!

This contest is open to everyone, but we’re also looking for the best projects to come from students and hackerspaces. We’ll be giving away two amazing 3D printers to the best Student entry and best Organization entry. These two top projects will be awarded an Original Prusa i3 MK3 with the Quad Material upgrade kit. This is one of the finest 3D printers you can buy right now, and we’re giving these away to the best student, hackerspaces, robotics club, or tool lending library.

If you have a project in mind, head on over to Hackaday.io and create a project demonstrating your 3D printed repair!

What is This Contest All About?

This contest is all about Repairs You Can Print, but what does that actually mean? Instead of printing Pokemon or plastic baubles on your desktop CNC machine, we’re looking for replacement parts. We’re looking for commercial, off the shelf items that were broken, but repaired with the help of a 3D printer. Is your repair good enough to show off as part of the contest? Yes! That’s the point, we want to see the clever repair jobs that people often don’t spend much time talking about because they just work.

Need some examples? Sure thing.

The underside of a vacuum cleaner
A 3D printed wheel for a broken vacuum cleaner

A while back, [Elliot Williams], one of the fantastic Hackaday Editors, had a broken vacuum cleaner. The wheels were crap, but luckily they were designed as a single part that snaps into a swivel socket. Over six or so years, the original wheels in this vacuum gave out, but a replacement part was quickly printed and stuffed into the socket. The new wheels have been going strong for a year now. That’s an entire year of use for a vacuum for five cents worth of plastic and an hour’s worth of printing time.

Need another example? My suitcase was apparently dragged behind a luggage cart for miles at either ORD or PHL. When it arrived on the baggage carousel, one wheel was shredded, and the wheel mount was ground down to almost the axle. The rest of the bag was still good, and I just removed the old wheel, salvaged the bearings, and printed a new wheel out of PLA. This suitcase has now traveled 60,000 miles with a 3D printed wheel, and it’s only now looking worse for wear.

How To Get In On The Action

We’re looking for the best repairs, jigs, and tools you’ve ever printed. To get started, head on over to Hackaday.io, create a new project, and document your repair. The Repairs You Can Print contest will run from Tuesday, January 16th, 2018 through 12 PM PST Tuesday, February 20th, 2018. Here’s a handy count down timer for ‘ya.

Miss Beatrice Shilling Saves The Spitfire

January 16, 2018 by 54 Comments

On a bright spring morning in 1940, the Royal Air Force pilot was in the fight of his life. Strapped into his brand new Supermarine Spitfire, he was locked in mortal combat with a Luftwaffe pilot over the English Channel in the opening days of the Battle of Britain. The Spitfire was behind the Messerschmitt and almost within range to unleash a deadly barrage of rounds from the four eight Browning machine guns in the leading edges of the elliptical wings. With the German plane just below the centerline of the gunsight’s crosshairs, the British pilot pushed the Spit’s lollipop stick forward to dive slightly and rake his rounds across the Bf-109. He felt the tug of the harness on his shoulders keeping him in his seat as the nimble fighter pulled a negative-g dive, and he lined up the fatal shot.

But the powerful V-12 Merlin engine sputtered, black smoke trailing along the fuselage as the engine cut out. Without power, the young pilot watched in horror as the three-bladed propeller wound to a stop. With the cold Channel waters looming in his windscreen, there was no time to restart the engine. The pilot bailed out in the nick of time, watching his beautiful plane cartwheel into the water as he floated down to join it, wondering what had just happened.

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You’ll Really Want An “Undo” Button When You Accidentally Send A Ballistic Missile Warning

January 16, 2018 by 91 Comments

Hawaiians started their weekend with quite a fright, waking up Saturday morning to a ballistic missile alert that turned out to be a false alarm. In between the public anger, profuse apologies from officials, and geopolitical commentary, it might be hard to find some information for the more technical-minded. For this audience, The Atlantic has compiled a brief history of infrastructure behind emergency alerts.

As a system intended to announce life-critical information when seconds count, all information on the system is prepared ahead of time for immediate delivery. As a large hodgepodge linking together multiple government IT systems, there’s no surprise it is unwieldy to use. These two aspects collided Saturday morning: there was no prepared “Sorry, false alarm” retraction message so one had to be built from scratch using specialized equipment, uploaded across systems, and broadcast 38 minutes after the initial false alarm. In the context of government bureaucracy, that was really fast and must have required hacking through red tape behind the scenes.

However, a single person’s mistake causing such chaos and requiring that much time to correct is unacceptable. This episode has already prompted a lot of questions whose answers will hopefully improve the alert system for everyone’s benefit. At the very least, a retraction is now part of the list of prepared messages. But we’ve also attracted attention of malicious hackers to this system with obvious problems in design, in implementation, and also has access to emergency broadcast channels. The system needs to be fixed before any more chaotic false alarms – either accidental or malicious – erode its credibility.

We’ve covered both the cold-war era CONELRAD and the more recent Emergency Broadcast System. We’ve also seen Dallas’ tornado siren warning system hacked. They weren’t the first, they won’t be the last.

(Image: Test launch of an unarmed Minuteman III ICBM via US Air Force.)

New Part Day: MEMS Loudspeakers

January 16, 2018 by 47 Comments

MEMS, or Micro ElectroMechanical Systems, are the enabling technology that brings us smartphones, quadcopters, tire pressure monitors, and a million other devices we take for granted today. At its most basic level, MEMS is simply machining away silicon wafers to make not electronic parts, but electromechanical parts. The microphone in your cell phone isn’t an electret mic you would find in an old brick phone from the 80s — it’s a carefully crafted bit of silicon, packed in epoxy, and hanging off a serial bus.

Despite the incredible success of MEMS technology, there is still something in your smartphone that’s built on 19th-century technology. Loudspeakers haven’t changed ever, and the speaker in your newest iThing is still a coil of wire and some sort of cone.

Now there’s finally a MEMS loudspeaker A company called USound has developed the first loudspeaker that isn’t just a bunch of wire and a magnet. This is a speaker built from a silicon wafer that can be as small as 3 mm square, and as thin as 1 mm. Since these speakers are built on silicon, you can also add an amp right onto the package. This is quite literally a speaker on a chip, and we’d bet that there are already engineers at Samsung looking at stuffing this into a flagship phone.

ST and USound announced these extraordinarily small speakers would actually be made, but so far it’s been just that — an announcement. This changed at CES where ST demonstrated VR goggles with multiple MEMS speakers. Does this mean MEMS speakers are on their way to Mouser and Digikey? We eagerly await the product announcement and demo dev board kit.