Have Some Candy While I Steal Your Cycles

Distributed computing is an excellent idea. We have a huge network of computers, many of them always on, why not take advantage of that when the user isn’t? The application that probably comes to mind is Folding@home, which lets you donate your unused computer time to help crunch the numbers for disease research. Everyone wins!

But what if your CPU cycles are being used for profit without your knowledge? Over the weekend this turned out to be the case with Showtime on-demand sites which mined Monero coins while the users was pacified by video playback. The video is a sweet treat while the cost of your electric bill is nudged up ever so slightly.

It’s an interesting hack as even if the user notices the CPU maxing out they’ll likely dismiss it as the horsepower necessary to decode the HD video stream. In this case, both Showtime and the web analytics company whose Javascript contained the mining software denied responsibility. But earlier this month Pirate Bay was found to be voluntarily testing out in-browser mining as a way to make up for dwindling ad revenue.

This is a clever tactic, but comes perilously close to being malicious when done without the user’s permission or knowledge. We wonder if those ubiquitous warnings about cookie usage will at times include notifications about currency mining on the side? Have you seen or tried out any of this Javascript mining? Let us know in the comments below.

Cryptocurrency Mining Post-Bitcoin

While the age of using your own computer to mine Bitcoin during spare CPU cycles has long passed, average folks aren’t entirely shut out of the cryptocurrency game yet. Luckily, Bitcoin isn’t the only game in town anymore, and with GPUs coming down in price it’s possible to build a mining rig for other currencies like Etherium.

[Chris]’s build starts with some extruded aluminum and a handful of GPUs. He wanted to build something that didn’t take up too much space in the small apartment. Once the main computer was installed, each GPU was installed upwards in the rack, with each set having its own dedicated fan. After installing a fan controller and some plexiglass the rig was up and running, although [Chris] did have to finagle the software a little bit to get all of the GPUs to work properly.

While this build did use some tools that might only be available at a makerspace, like a mill and a 3D printer, the hardware is still within reason with someone with a little cash burning a hole in their pockets. And, if Etherium keeps going up in value like it has been since the summer, it might pay for itself eventually, providing that your electric utility doesn’t charge too much for power.

And if you missed it, we just ran a feature on Etherium.  Check it out.

World’s Worst Bitcoin Mining Rig

Even if we don’t quite understand what’s happening in a Bitcoin mine, we all pretty much know what’s needed to set one up. Racks of GPUs and specialized software will eventually find a few of these vanishingly rare virtual treasures, but if you have enough time, even a Xerox Alto from 1973 can be turned into a Bitcoin mine. As for how much time it’ll take [Ken Shirriff]’s rig to find a Bitcoin, let’s just say that his Alto would need to survive the heat death of the universe. About 5000 times. And it would take the electricity generated by a small country to do it.

Even though it’s not exactly a profit center, it gives [Ken] a chance to show off his lovingly restored Alto. The Xerox machine is the granddaddy of all modern PCs, having introduced almost every aspect of the GUI world we live in. But with a processor built from discrete TTL chips and an instruction set that doesn’t even have logical OR or XOR functions, the machine isn’t exactly optimized for SHA-256 hashing. The fact that [Ken] was able to implement a mining algorithm at all is impressive, and his explanation of how Bitcoin mining is done is quite clear and a great primer for cryptocurrency newbies.

[Ken] seems to enjoy sending old computer hardware to the Bitcoin mines — he made an old IBM mainframe perform the trick a while back. But if you don’t have a room-size computer around, perhaps reading up on alternate uses for the block chain would be a good idea.

[via Dangerous Prototypes]

[Cody] Takes us From Rock To Ring

[Cody Reeder] had a problem. He wanted to make a ring for his girlfriend [Canyon], but didn’t have enough gold. [Cody and Canyon] spent some time panning for the shiny stuff last summer. Their haul was only about 1/3 gram though. Way too small to make any kind of jewelry. What to do? If you’re [Cody], you head up to your silver mine, and pick up some ore. [Cody] has several mines on his ranch in Utah. While he didn’t go down into the 75 foot deep pit this time, he did pick up some ore his family had brought out a few years back. Getting from ore to silver is a long process though.

splattersFirst, [Cody] crushed the rock down to marble size using his homemade rock crusher. Then he roasted the rock in a tire rim furnace. The ore was so rich in lead and silver that the some of the metal just dropped right out, forming splatters on the ground beneath the furnace. [Cody] then ball milled the remaining rock to a fine powder and panned out the rest of the lead. At this point the lead and silver were mixed together. [Cody] employed Parks process to extract the silver. Zinc was added to the molten lead mixture. The silver is attracted to the zinc, which is insoluble in lead. The result is a layer of zinc and silver floating above the molten lead. Extracting pure silver is just a matter of removing the zinc, which [Cody] did with a bit of acid.

Cody decided to make a silver ring for [Canyon] with their gold as the stone. He used the lost wax method to create his ring. This involves making the ring from wax, then casting that wax in a mold. The mold is then heated, which burns out the wax. The result is an empty mold, ready for molten metal.

The cast ring took a lot of cleanup before it was perfect, but the results definitely look like they were worth all the work.

Continue reading “[Cody] Takes us From Rock To Ring”

Turning the DEFCON Badge Into a Bitcoin Miner


The DEFCON badge this year was an impressive piece of hardware, complete with mind-bending puzzles, cap sense buttons, LEDs, and of course a Parallax Propeller. [mike] thought a chip as cool as the Propeller should be put to better use than just sitting around until next year so he turned it into a Bitcoin miner, netting him an astonishing 40 hashes per second.

Mining Bitcoins on hardware that doesn’t have much processing power to begin with (at least compared to the FPGAs and ASIC miners commonly used) meant [mike] would have to find some interesting ways to compute the SHA256 hashes that mining requires. He turned to RetroMiner, the Bitcoin miner made for an original Nintendo. Like the NES miner, [mike] is offloading the communication with the Bitcoin network to a host computer, but all of the actual math is handled by a single core on the Propeller.

Saving one core for communication with the host computer, a DEFCON badge could conceivably manage 280 hashes/second, meaning the processing power of all the badges made for DEFCON is about equal to a seven-year-old graphics card.