Mining Bitcoin On The ESP32 For Fun, Definitely Not Profit

March 19, 2019 by Lewin Day 7 Comments

Bitcoin’s great, if you sold at the end of 2017. If you’re still holding, your opinion might be a little more sour. The cost to compete in the great hashing race continues to rise while cryptocurrency values remain underwhelming. While getting involved at the top end is prohibitively expensive, you can still have some fun with the basic concepts – as [Jake] did, by calculating Bitcoin hashes on the ESP32.

It’s a project that is very much done for fun, rather than profit. [Jake] notes that even maxing out both cores, it would take 31 billion years to mine one block at current difficulty levels. Regardless, the underlying maths is nothing too crazy. Double-hashing the right data with the SHA256 algorithm is all that’s required, a task that is well within the ESP32’s capabilities. There’s hardware acceleration available, too – though this is weirdly slower than doing it in software.

Overall, you’re not going to get rich hashing Bitcoin on a cheap microcontroller platform. You might just learn something useful, though. If this isn’t weird enough though, you could always try the same thing on a 1970s Xerox Alto.

Rebuilding The First Vocal Encryption System

January 27, 2019 by Dan Maloney 12 Comments

Back in the early days of radio, it was quickly apparent that the technology would revolutionize warfare, but only if some way could be found to prevent enemies from hearing what was said. During World War II, the Allies put a considerable amount of effort into securing vocal transmissions, resulting in a system called SIGSALY – 50 tons of gear developed by Bell Laboratories with the help of Alan Turing that successfully secured communications between the likes of Churchill and Roosevelt during the war.

Now, a small piece of the SIGSALY system lives again, in the form of a period-faithful reproduction of the vocal quantizer used in the system. It’s the work of [Jon D. Paul], who undertook the build to better understand how the SIGSALY system worked. [Jon] also wanted to honor the original builders, who developed a surprisingly sophisticated system given the technology of the day.

SIGSALY was seriously Top Secret in the day, and most of the documentation was destroyed when the system was decommissioned. Working from scant information, [Jon] was able to recreate the quantizer from period parts, including five vintage VT-109/2051 thyratrons scrounged from eBay. The vacuum tubes are similar in operation to silicon-controlled rectifiers (SCRs) and form the core of the ADC, along with a resistor divider ladder network. Almost every component is period correct, and everything is housed in a nice acrylic case. It’s a beautiful piece of work and a great homage to a nearly forgotten piece of cryptographic history.

Interestingly, Bell Labs had a bit of a head start on the technology that went into SIGSALY, by virtue of their work on the first voice synthesizer in the 1930s.

Continue reading “Rebuilding The First Vocal Encryption System” →

What Can The Blockchain Do For You?

October 25, 2018 by Brian Benchoff 40 Comments

Imagine you’re a general, camped outside a fortified city with your army. Your army isn’t strong enough to take the city without help. But you do have help: camped on other hills outside this city are a half dozen more generals, with their armies ready to attack. Attacking one army at a time will fail; taking this city will require at least three or four armies, and an uncoordinated attack will leave thousands dead outside the city gates. How do you coordinate an attack with the other generals? Now, how do you coordinate your attack if one of those other generals is Benedict Arnold? What happens when one of the generals is working with the enemy?

This situation is a slight rephrasing of the Byzantine Generals Problem, first presented in the ACM Transactions on Programming Languages and Systems in 1982. It’s related to the Two Generals Problem formulated a decade prior. These are the analogies we use when we talk about trust over a communications channel, how hard it is to transmit knowledge, and how to form a consensus around imperfect facts.

This problem was upended in late 2008 when Satoshi Nakamoto, a person or group of people, published a white paper on the ‘block chain’. This was the solution to double-spending in digital currency. Think of it as having a digital thing that only one person could own. As a test of this block chain technology, Bitcoin was launched at the beginning of 2009. Things got more annoying from there.

Now, blockchain is at the top of the hype cycle. Every industry is looking at blockchain tech to figure out how it will work for them. Kodak launched their own blockchain, there are proposals to use the blockchain in drones and 3D printers. Medical records could be stored on the blockchain, HIPAA be damned, and there’s a blockchain phone, for reasons. This doesn’t even cover the massive amount of speculation in Bitcoin itself; thousands of other cryptocurrencies have also sprung up, and people are losing money.

The blockchain is a confusing thing, with hashes and Merkle trees and timestamps. Everyone is left asking themselves, what does the blockchain actually do? Is there an independent body out there that will tell me what the blockchain is good for, and when I should use it? You’re in luck: NIST, the National Institute of Standards and Technology released their report on blockchain technology (PDF). Is blockchain magic? No, no it is not, and it probably shouldn’t be used for anything other than a currency.

Continue reading “What Can The Blockchain Do For You?” →

RGB Sensor’s New Job: Cryptocurrency Trade Advisor

July 8, 2018 by Donald Papp 15 Comments

[XenonJohn] dabbles in cryptocurrency trading, and when he saw an opportunity to buy an RGB color sensor, his immediate thought — which he admitted to us would probably not be the immediate thought of most normal people — was that he could point it to his laptop screen and have it analyze the ratio of green (buy) orders to red (sell) orders being made for crypto trading. In theory, if at a given moment there are more people looking to buy than there are people looking to sell, the value of a commodity could be expected to go up slightly in the short-term. The reverse is true if a lot of sell orders coming in relative to buy orders. Having this information and possibly acting on it could be useful, but then again it might not. Either way, as far as out-of-left-field project ideas go, promoting an RGB color sensor to Cryptocurrency Trading Advisor is a pretty good one.

Since the RGB sensor only sees what is directly in front of it, [XenonJohn] assembled a sort of simple light guide. By enclosing the area of the screen that contains orders in foil-lined cardboard, the sensor can get a general approximation of the amount of red (sell orders) versus green (buy orders). The data gets read by an Arduino which does a simple analysis and sends alerts when a threshold is crossed. He dubbed it the Crypto-Eye, and a video demo is embedded below.

Continue reading “RGB Sensor’s New Job: Cryptocurrency Trade Advisor” →

This Year, Badges Get Blockchains

June 28, 2018 by Brian Benchoff 11 Comments

This year’s hottest new advance in electronics comes through wearable badges. You can’t have failed to notice another technology that’s getting really hot. It’s the blockchain. What is a blockchain? It’s a linked list where every item in the list contains a cryptographic hash of the previous item in the list. What is a blockchain in English? It’s the most revolutionary technology that’s going to solve every problem on the planet, somehow. It’s the basis for crypto (no not that one, the other one). The blockchain is how you add more Lamborghinis to your Lamborghini account. Even though we’re still trying to figure out how it solves a single problem, one thing is certain: blockchains solve every problem. We were born too late to explore the Earth, born too early to explore the Universe, but just in time for blockchain.

Independent badges are always looking at the latest technology, and perhaps this was inevitable. It’s a badge built on the blockchain. It’s a wearable sneakernet of mining. It’s a game with collaborative proof of work.

The blockchain badge from [Mr Blinky Bling] is an independent badge for this year’s Defcon, and like most independent badges it’s loaded up with RGB LEDs, microcontrollers, and exquisitely crafted FR4. What makes this badge different is the add-ons, or ‘blocks’ that attach to the main badge through 1/8″ phono jacks. These blocks form the basis of the social game, where two badge holders trade blocks for a while, allow their badges to perform a proof of work on each block, and finally, each block is hashed and the score increased. Yes, this is a blockchain, but it’s more of a block-tree, and it runs on sneakernet instead of the Internet.

Yes, this does indeed all sound like a joke. Make no mistake, though: this is real. This is a hardware game built on blockchain technology, that some lucky badge holders will be playing at this year’s Defcon. It’s filled with blinky and blockchain. It’s awesome.

[Mr. Blinky Bling] has already started a project for this badge over on hackaday.io, and right now they’re running a Kickstarter campaign for this badge with delivery at Defcon. This is one of the more interesting badges that will be floating around the con this year, and it has blockchain. This really isn’t one to miss.

Hackaday Links: June 3, 2018

June 3, 2018 by Brian Benchoff 26 Comments

All the Radio Shacks are dead. adioS, or something. But wait, what’s this? There are new Radio Shacks opening. Here’s one in Idaho, and here’s another in Claremore, Oklahoma. This isn’t like the ‘Blockbuster Video in Nome, Alaska’ that clings on by virtue of being so remote; Claremore isn’t that far from Tulsa, and the one in Idaho is in a town with a population of 50,000. Are these corporate stores, or are they the (cool) independent Radio Shacks? Are there component drawers? Anyone want to take a field trip and report?

A few years ago, [cnxsoft] bought a Sonoff WiFi switch to control a well pump. Despite this being a way to control the flow of massive amounts of water with an Internet of Things thing, we’re still rocking it antediluvian style, and for the most part this WiFi-connected relay worked well. Until it didn’t. For the past few days, the switch wouldn’t connect to the network, so [cnxsoft] cracked it open to figure out why. There was one burnt component, and more than one electrocuted insect. Apparently, an ant bridged two pins, was shortly electrocuted, and toasted a resistor. It’s a bug, a real bug, in an Internet of Things thing.

eInk is coming to license plates? Apparently. Since an eInk license plate already includes some electronics, it wouldn’t be much to add some tracking hardware for a surveillance state.

Hold up, it’s a press release about crypto hardware. No, not that crypto, the other crypto. Asus has announced a new motherboard that is capable of supporting twenty graphics cards. This isn’t a six-foot-wide motherboard; it’s designed especially for coin mining, and for that, the graphics cards really only need a PCIe x1 connection. The real trick here is not using PCIe headers, and instead piping everything over vertical-mount USB ports. Yes, this is a slight cabling nightmare. So, you still think the early 80s with fluorinert waterfalls and Blinkenlights that played Game of Life was the pinnacle of style in computer hardware? No, this is it right here.

Here’s a book you should read. Ignition!: An Informal History of Liquid Rocket Propellants by John Drury Clark is a fantastic book about how modern liquid rocket fuel came to be. Want to know why 60s cartoons and spy movies always referenced a ‘secret rocket fuel formula’ when kerosene and liquid oxygen work just fine? This is that. Back when we covered it, the book, used, on Amazon, cost $500. It’s now in print again and priced reasonably. It’s on the Inc. 9 Powerful Books Elon Musk Recommends list, so you know it’s good. Thanks, [Ben] for sending this one in on the tip line.

Distorted Text Says A Lot

May 31, 2018 by Brian McEvoy 21 Comments

Getting bounced to a website by scanning a QR code is no longer an exciting feat of technology, but what if you scanned the ingredient list on your granola bar and it went to the company’s page for that specific flavor, sans the matrix code?

Bright minds at the Columbia University in the City of New York have “perturbed” ordinary font characters so the average human eye won’t pick up the changes. Even ordinary OCR won’t miss a beat when it looks at a passage with a hidden message. After all, these “perturbed” glyphs are like a perfectly legible character viewed through a drop of water. When a camera is looking for these secret messages, those minor tweaks speak volumes.

The system is diabolically simple. Each character can be distorted according to an algorithm and a second variable. Changing that second variable is like twisting a distorted lens, or a water drop but the afterimage can be decoded and the variable extracted. This kind of encoding can survive a trip to the printer, unlike a purely digital hidden message.

Hidden messages like these are not limited to passing notes, metadata can be attached to any text and extracted when necessary. Literature could include notes without taking up page space so teachers could include helpful notes and a cell phone could be like an x-ray machine to see what the teacher wants to show. For example, you could define what “crypto” actually means.

Continue reading “Distorted Text Says A Lot” →