Don’t Be A Code Tyrant, Be A Mentor

May 16, 2017 by Adam Fabio 168 Comments

Hardware hacking is a way of life here at Hackaday. We celebrate projects every day with hot glue, duct tape, upcycled parts, and everything in between. It’s open season to hack hardware. Out in the world, for some reason software doesn’t receive the same laissez-faire treatment. “Too many lines in that file” “bad habits” “bad variable names” the comments often rain down. Even the ~~unsafest~~ silliest of projects isn’t safe. Building a robot to shine lasers into a person’s eyes? Better make sure you have less than 500 lines of code per file!

Why is this? What makes readers and commenters hold software to a higher standard than the hardware it happens to be running on? The reasons are many and varied, and it’s a trend I’d like to see stopped.

Software engineering is a relatively young and fast evolving science. Every few months there is a new hot language on the block, with forums, user groups, and articles galore. Even the way software engineers work is constantly changing. Waterfall to agile, V-Model, Spiral model. Even software design methodologies change — from pseudo code to UML to test driven development, the list goes on and on.

Terms like “clean code” get thrown around. It’s not good enough to have software that works. Software must be well commented, maintainable, elegant, and of course, follow the best coding practices. Most of these are good ideas… in the work environment. Work is what a lot of this boils down to. Software engineers have to stay up to date with new trends to be employable.

There is a certain amount of “born again” mentality among professional software developers. Coders generally hate having change forced upon them. But when they find a tool or system they like, they embrace it both professionally, and in their personal projects. Then they’re out spreading the word of this new method or tool; on Reddit, in forums, to anyone who will listen. The classic example of this is, of course, editors like the vi vs emacs debate.

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Automate The Freight: Medical Deliveries By Drone

May 12, 2017 by Dan Maloney 26 Comments

Being a cop’s kid leaves you with a lot of vivid memories. My dad was a Connecticut State Trooper for over twenty years, and because of the small size of the state, he was essentially on duty at all times. His cruiser was very much the family vehicle, and like all police vehicles, it was loaded with the tools of the trade. Chief among them was the VHF two-way radio, which I’d listen to during long car rides, hearing troopers dispatched to this accident or calling in that traffic stop.

One very common call was the blood relay — Greenwich Hospital might have had an urgent need for Type B+ blood, but the nearest supply was perhaps at Yale-New Haven Hospital. The State Police would be called, a trooper would pick up the blood in a cooler, drive like hell down I-95, and hand deliver the blood to waiting OR personnel. On a good day, a sufficiently motivated and skilled trooper could cover that 45-mile stretch in about half an hour. On a bad day, the trooper might end up in an accident and in need of blood himself.

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History Of Git

May 11, 2017 by Al Williams 89 Comments

Git is one of those tools that is so simple to use, that you often don’t learn a lot of nuance to it. You wind up cloning a repository from the Internet and that’s about it. If you make changes, maybe you track them and if you are really polite you might create a pull request to give back to the project. But there’s a lot more you can do. For example, did you know that Git can track collaborative Word documents? Or manage your startup files across multiple Linux boxes?

Git belongs to a family of software products that do revision (or version) control. The idea is that you can develop software (for example) and keep track of each revision. Good systems have provisions for allowing multiple people to work on a project at one time. There is also usually some way to split a project into different parts. For example, you might split off to develop a version of the product for a different market or to try an experimental feature without breaking the normal development. In some cases, you’ll eventually bring that split back into the main line.

Although in the next installment, I’ll give you some odd uses for Git you might find useful, this post is mostly the story of how Git came to be. Open source development is known for flame wars and there’s at least a few in this tale. And in true hacker fashion, the hero of the story decides he doesn’t like the tools he’s using so… well, what would you do?

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How A Hacker Remembers A PIN

May 10, 2017 by Elliot Williams 98 Comments

If you have more than a few bank cards, door-entry keycodes, or other small numeric passwords to remember, it eventually gets to be a hassle. The worst, for me, is a bank card for a business account that I use once in a blue moon. I probably used it eight times in five years, and then they gave me a new card with a new PIN. Sigh.

How would a normal person cope with a proliferation of PINs? They’d write down the numbers on a piece of paper and keep it in their wallet. We all know how that ends, right? A lost wallet and multiple empty bank accounts. How would a hacker handle it? Write each number down on the card itself, but encrypted, naturally, with the only unbreakable encryption scheme there is out there: the one-time pad (OTP).

The OTP is an odd duck among encryption methods. They’re meant to be decrypted in your head, but as long as the secret key remains safe, they’re rock solid. If you’ve ever tried to code up the s-boxes and all that adding, shifting, and mixing that goes on with a normal encryption method, OTPs are refreshingly simple. The tradeoff is a “long” key, but an OTP is absolutely perfect for encrypting your PINs.

The first part of this article appears to be the friendly “life-hack” pablum that you’ll get elsewhere, but don’t despair, it’s also a back-door introduction to the OTP. The second half dives into the one-time pad with some deep crypto intuition, some friendly math, and hopefully a convincing argument that writing down your encrypted PINs is the right thing to do. Along the way, I list the three things you can do wrong when implementing an OTP. (And none of them will shock you!) But in the end, my PIN encryption solution will break one of the three, and remain nonetheless sound. Curious yet? Read on.

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Number Twitters

May 9, 2017 by Brian Benchoff 47 Comments

Grab a shortwave radio, go up on your roof at night, turn on the radio, and if the ionosphere is just right, you’ll be able to tune into some very, very strange radio stations. Some of these stations are just a voice — usually a woman’s voice — simply counting. Some are Morse code. All of them are completely unintelligible unless you have a secret code book. These are number stations, or radio stations nobody knows much about, but everyone agrees they’re used to pass messages from intelligence agencies to spies in the field.

A few years ago, we took a look at number stations, their history, and the efforts of people who document and record these mysterious messages used for unknown purposes. These number stations exist for a particular reason: if you’re a spy, you would much rather get caught with an ordinary radio instead of a fancy encryption machine. Passing code through intermediaries or dead drops presents a liability. The solution to both these problems lies in broadcasting messages in code, allowing anyone to receive them. Only the spy who holds a code book — or in the case of the Cuban Five, software designed to decrypt messages from number stations — can decipher the code.

Number stations are a hack, of sorts, of the entire concept of broadcasting. For all but a few, these number stations broadcast complete gibberish. Only to the person holding the code book or the decryption software do these number stations mean anything. However, since the first number stations went on the air over one hundred years ago, broadcasting has changed dramatically. We now have the Internet, and although most web services cannot be considered a one-to-many distribution as how broadcasting is defined, Twitter can. Are there number stations on Twitter? There sure are. Are they used by spies or agents of governments around the world? That’s a little harder to say.

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A Queen Mystery: The Legend Of The Deacy Amp

May 8, 2017 by Adam Fabio 56 Comments

It sounds like a scene from a movie. A dark night in London, 1972. A young man walks alone, heading home after a long night of practicing with his band. His heavy Fender bass slung over his back, he’s weary but excited about the future. As he passes a skip (dumpster for the Americans out there), a splash of color catches his attention. Wires – not building power wires, but thinner gauge electronics connection wire. A tinkerer studying for his Electrical Engineering degree, the man had to investigate. What he found would become rock and roll history, and the seed of mystery stretching over 40 years.

The man was John Deacon, and he had recently signed on as bassist for a band named Queen. Reaching into the skip, he found the wires attached to a circuit board. The circuit looked to be an amplifier. Probably from a transistor radio or a tape player. Queen hadn’t made it big yet, so all the members were struggling to get by in London.

Deacon took the board back home and examined it closer. It looked like it would make a good practice amplifier for his guitar. He fit the amp inside an old bookshelf speaker, added a ¼ “ jack for input, and closed up the case. A volume control potentiometer dangled out the back of the case. Power came from a 9-volt battery outside the amp case. No, not a tiny transistor battery; this was a rather beefy PP-9 pack, commonly used in radios back then. The amp sounded best cranked all the way up, so eventually, even the volume control was removed. John liked the knobless simplicity – just plug in the guitar and play. No controls to fiddle with.

And just like that, The Deacy amp was born.

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A Brief History Of Radioactivity

May 1, 2017 by Manuel Rodriguez-Achach 58 Comments

More than one hundred years ago, Henri Becquerel discovered that uranium emitted penetrating rays similar to those used by Wilhelm Röntgen to take the first X-ray image (of his wife’s hand), starting a new era of far-reaching applications. There are of course many dangers that come with the use of radioactivity, but there are also many beneficial uses for our society.

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