THE INSATIABLE DO YOU NEED THE BLOCK-CHAINING THE MONEY MINES BITCOIN BEAST A BLOCKCHAIN? OF WALL STREET OF MONGOLIA Cryptocurrency’s Find out in seconds A new platform for How watts coming energy crisis with our handy guide trading in the trillions become bitcoins P. 36 P. 38 P. 40 P. 46 FOR THE TECHNOLOGY INSIDER | 10.17 BLOCK- CHAIN WORLD SPECIAL REPORT The tech behind Bitcoin has been released into the wild. Here’s how it’s going to change the landscape P. 24 SUPERMICRO® BigTwin® The IT Industry’s Highest Performing Twin Multi-Node System 2U Multi-Node System Supporting • A Full Range of Processors Up to the highest performing 205 watt CPUs • Maximum Memory 3TB 24 DIMMs per node • All-Flash NVMe 24 All Flash NVMe or Hybrid NVMe/SAS3 drives • Double the I/O Capacity Three PCI-E 3.0 x16 options per node • Supports Intel® Xeon® Scalable Processors Intel Inside®. Powerful Productivity Outside. Learn more at supermicro.com/GPU © Super Micro Computer, Inc. Specifications subject to change without notice. Intel, the Intel logo, Xeon, and Xeon Inside are trademarks or registered trademarks of Intel Corporation in the U.S. and/or other countries. 10.17 Special Report: BLOCKCHAIN WORLD The Blossoming 26 Blockchains: How They 45 Blockchain Lingo Work and Why They’ll Change Your cheat sheet for all things blockchain. of Blockchain the World 24 Enthusiasts The technology behind Bitcoin could touch every 46 Photo Essay: are sure that transaction you ever make. By Morgen E. Peck The Bitcoin Mines of China This Bitcoin operation in Inner Mongolia uses blockchain 36 Feeding the sophisticated semiconductors to turn cheap, dirty technology is Blockchain Beast energy into digital cash. Text by Morgen E. Peck going to take over By 2020, Bitcoin will probably be using as much Photography by Stefen Chow electricity as Denmark, and that’s a problem. the world. We set By Peter Fairley 54 Govern by Blockchain out to discover Can blockchains cut government red tape? if they’re right. 38 Do You Need a Blockchain? Dubai and Illinois may be the first to find out. This chart will tell you if the technology can solve By Amy Nordrum By Morgen E. Peck your problem. By Morgen E. Peck & Samuel K. Moore 56 Energy Trading for 40 Wall Street Occupies Fun and Profit the Blockchain Buy your neighbor’s rooftop solar power or Financial firms now want to adopt the technology that was sell yours—it’ll all be on a blockchain. predicted to render them obsolete. By Amy Nordrum By Morgen E. Peck & David Wagman On the cover and above Illustrations for IEEE Spectrum by Mario De Meyer SPECTRUM.IEEE.ORG | NORTH AMERICAN | OCT 2017 | 01 Make the Connection Find the simple way through complex EM systems with CST STUDIO SUITE Components don’t exist in electromag- If you’re more interested in filters, couplers, netic isolation. They influence their neigh- planar and multilayer structures, we’ve a bors’ performance. They are affected by wide variety of worked application exam- the enclosure or structure around them. ples live on our website at They are susceptible to outside influ- www.cst.com/apps. ences. With System Assembly and Mode- ling, CST STUDIO SUITE helps optimize Get the big picture of what’s really going component and system performance. on. Ensure your product and components perform in the toughest of environments. Involved in antenna development? You can read about how CST technology is Choose CST STUDIO SUITE – used to simulate antenna performance at Complete Technology for 3D EM. www.cst.com/antenna. joins CST, a Dassault Systèmes company | www.cst.com | [email protected] DEPARTMENTS_01.13DEPARTMENTS_10.17 09 15 08 Online News Resources Opinion spectrum.ieee.org Advances in Magnetic Tape Tech Halloween Hack Make the Web Better for Everyone The Bandwidth Defender Keep Unspooling A wearable Python-based It’s ubiquitous, but it delights as IEEE Spectrum spent a day in Thinner tape, tinier bits, and smarter microcontroller and some LEDs much as it annoys. Must it stay the field with a radio-frequency- error correction yield a cartridge transform a cheap costume. that way? interference hunter. His job is that puts 330 million books’ worth By Stephen Cass By G. Pascal Zachary to find gadgets that are illegally of data in the palm of your hand. transmitting signals in licensed By Prachi Patel 17 S tartups: LPPFusion Turns 04 Back Story frequency bands and ask their Instability to Its Advantage 06 Contributors owners to shut them off. Watch the 11 Nuclear Power’s Last Hope? 18 R eview: The Deep History of 20 Numbers Don’t Lie: video at http://spectrum.ieee.org/ 13 AI Versus Doctors Humanoid Robots Sputnik Turns 60 rfhunters1017 14 Self-Driving Wheelchairs Debut 72 Past Forward: 22 Technically Speaking: Software as Hardware Dark Web Dialect ADDITIONAL RESOURCES Tech Insider / Webinars The Institute Available at spectrum.ieee.org/webinars Available at theinstitute.ieee.org Efficient Design of Integrated Photonic Circuits AUTOMATED TRADING Sentient.AI, a San Francisco–based startup, has Fluid-Structure Interaction Analysis of a Piezoelectric Fan completely automated its hedge fund using its own AI software. IEEE Fellow Risto Miikkulainen, the company’s chief research officer, explains how it was White Papers developed through trial and error over the past decade. Available at http://spectrum.ieee.org/whitepapers HISTORY OF THE STOCK TICKER One of Thomas Edison’s first inventions, the stock ticker revolutionized the speed at which financial Sequential Peeling: A Model-Based Approach to Structure Identification information flowed. and De-embedding Fundamentals to Building a Test System: Automated Test Power HONEST DOLLAR Senior Member William Hurley sold his startup— Infrastructure which created a way for those without employer-sponsored retirement Selecting Current Sensors and Transformers plans to invest toward their future—to Goldman Sachs. Unified Storage: Software-Defined Storage Made Easy Capacitor Selection for Switch Mode Power Supply Applications IEEE SPECTRUM (ISSN 0018-9235) is published monthly by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved. © 2017 by The Institute of Electrical and Electronics Engineers, Inc., 3 Park Avenue, New York, NY 10016-5997, U.S.A. Volume No. 54, issue No. 10, North American edition. The editorial content of IEEE Spectrum magazine does not represent official positions of the IEEE or its organizational units. Canadian Post International Publications Mail (Canadian Distribution) Sales Agreement No. 40013087. Return undeliverable Canadian addresses to: Circulation Department, IEEE Spectrum, Box 1051, Fort Erie, ON L2A 6C7. Cable address: ITRIPLEE. Fax: +1 212 419 7570. INTERNET: [email protected]. ANNUAL SUBSCRIPTIONS: IEEE Members: $21.40 included in dues. Libraries/institutions: $399. POSTMASTER: Please send address changes to IEEE Spectrum, c/o Coding Department, IEEE Service Center, 445 Hoes Lane, Box 1331, Piscataway, NJ 08855. Periodicals postage paid at New York, NY, and additional mailing offices. Canadian GST #125634188. Printed at 120 Donnelley Dr., Glasgow, KY 42141-1060, U.S.A. IEEE Spectrum circulation is audited by BPA Worldwide. IEEE Spectrum is a member of the Association of Business Information & Media Companies, the Association of Magazine Media, and FROM LEFT: EMILY COOPER; RANDI KLETT; ALYSSA PAGANO ALYSSA KLETT; RANDI COOPER; EMILY LEFT: FROM Association Media & Publishing. IEEE prohibits discrimination, harassment, and bullying. For more information, visit http://www.ieee.org/web/aboutus/whatis/policies/p9-26.html. SPECTRUM.IEEE.ORG | NORTH AMERICAN | OCT 2017 | 03 BACK STORY_ Safety meets performance The Mines of Mongolia n 4 July, Morgen e. Peck woke up in the middle of the night with a slight case of panic. For three months, she had been pressing officials at Bitmain, a Chinese bitcoin-mining hardware company, to allow her to tour a mining facility it runs in Inner Mongolia. And for two months she had received encouraging but noncommittal responses. Now, though, time was about to run out because the deadlines were looming for O our October issue. Miners can be an evasive bunch, she says. “I had visited a few small mines in central China before and been greeted by snarling watchdogs Arm C/C++ and shirtless, screaming watch-humans.” So getting entry to Bitmain would take patience and a battering ram of charm. Compiler Late on the 4th, it paid off, and the trip was approved. A week later she flew to Baotou, a city in Inner Mongolia that’s near Bitmain’s mines. The setting provided a stark contrast to the clean idealism of the Bitcoin for functional project. “Baotou was probably the ugliest place I’ve ever been,” says Peck. “A coal plant sits right in the middle of the city. Foliage everywhere safety covered in soot. A filthy discolored river snaking through it all. These are the places that keep Bitcoin running. You don’t think about all that when you’re nibbling a lunch of baked salmon at a blockchain industry conference listening to someone tell you how Bitcoin is the salvation for the unbanked.” Despite the initial ambivalence of her hosts, when Peck arrived she found them fully committed to transparency. The only scrutiny came from the local police chief. “He was obviously on good terms with everyone there. Which was interesting in itself, as other miners I’ve visited were clearly skirting the law,” says Peck. “Here, though, I was the Visit only person he was worried about.” ■ developer.arm.com/compiler CITING ARTICLES IN IEEE SPECTRUM IEEE Spectrum publishes an international and a North American edition, as 10.17 indicated at the bottom of each page. Both have the same edit orial content, but because of diff erences in advertising, page numbers may differ.