Bitcoin is a purely online virtual currency, unbacked by either physical commodities or sovereign obligation; instead, it relies on a combination of cryptographic protection and a peer-to-peer protocol for witnessing settlements. Consequently, Bitcoin has the unintuitive property that while the ownership of money is implicitly anonymous, its flow is globally visible. In this paper we explore this unique characteristic further, using heuristic clustering to group Bitcoin wallets based on evidence of shared authority, and then using re-identification attacks (i.e., empirical purchasing of goods and services) to classify the operators of those clusters. From this analysis, we consider the challenges for those seeking to use Bitcoin for criminal or fraudulent purposes at scale. Demand for low friction e-commerce of various kinds has driven a proliferation in online payment systems over the last decade. Thus, in addition to established payment card networks (e.g., Visa and Mastercard), a broad range of the so-called "alternative payments" has emerged including eWallets (e.g., Paypal, Google Checkout, and WebMoney), direct debit systems (typically via ACH, such as eBillMe), money transfer systems (e.g., Moneygram), and so on. However, virtually all of these systems have the property that they are denominated in existing fiat currencies (e.g., dollars), explicitly identify the payer in transactions, and are centrally or quasi-centrally administered. By far the most intriguing exception to this rule is Bitcoin. First deployed in 2009, Bitcoin is an independent online monetary system that combines some of the features of cash and existing online payment methods. Like cash, Bitcoin transactions do not explicitly identify the payer or the payee: a transaction is a cryptographically signed transfer of funds from one public key to another.

When William Legrand finally decrypted the string, it did not seem to make much more sense than it did before. But at least it did sound more like natural language, and eventually guided the main character of Edgar Allan Poe's "The Gold-Bug"36 to discover the treasure he had been after. Legrand solved a substitution cipher using symbol frequencies. He first looked for the most frequent symbol and changed it into the most frequent letter of English, then similarly inferred the most frequent word, then punctuation marks, and so on. Both before and after 1843, the natural impulse when faced with some mysterious message has been to count frequencies of individual tokens or subassemblies in search of a clue. Perhaps one of the most intense and fascinating subjects for this kind of scrutiny have been biosequences. As soon as some such sequences became available, statistical analysts tried to link characters or blocks of characters to relevant biological functions.

Zittrain, J. Engineering an election – digital gerrymandering poses a threat to democracy.

The four-color map theorem says no more than four colors are required to color the regions of a two-dimensional map so no two adjacent regions have the same color. Over the past two decades, mathematicians have succeeded in bringing computers to bear on the development of proofs for conjectures that have lingered for centuries without solution. Following a small number of highly publicized successes, the majority of mathematicians remain hesitant to use software to help develop, organize, and verify their proofs. Yet concerns linger over usability and the reliability of computerized proofs, although some see technological assistance as being vital to avoid problems caused by human error. Troubled by the discovery in 2013 of an error in a proof he co-authored almost 25 years earlier, Vladimir Voevodsky of the Institute for Advanced Study at Princeton University embarked on a program to not only employ automated proof checking for his work, but to convince other mathematicians of the need for the technology.

More than 20% of U.S. adults live with some form of disability, according to a September 2015 report released by the U.S. Centers for Disease Control and Prevention. The latest generation of smartphones, tablets, and personal computers are equipped with accessibility features that make using these devices easier, or at least, less onerous, for those who have sight, speech, or hearing impairments. These enhancements include functions such as screen-reading technology (which reads aloud text when the user passes a finger over it); screen-flashing notification when a call or message comes in for the hearing impaired; and voice controls of basic functions for those who are unable to physically manipulate the phone or computing device's controls. Other technologies that can help the disabled have or are coming to market, and not all of them are focused simply on providing access to computers or smartphones. Irrespective of the accessibility provided, most market participants agree more needs to be done to help those with disabilities to fully experience our increasingly digital world.

It is widely regarded as one of the greatest human achievements ever made, but putting a man on the moon was no cheap undertaking. The Apollo missions to send just 12 men onto the dusty lunar surface cost 25 billion ( 17 billion) – estimated to be worth around 170 billion ( 120 billion) in modern monetary value. But it appears we may be able to send humans back to our rocky satellite and set up a permanent base where they could live for just a fraction of the cost. The cost of building a base on the moon could be a fraction of what has been previously expected. Scientists say it may be possible to build a permanent base (illustrated) housing 10 people within the next five to seven years for around 10 billion.

Nasa has announced that it has found evidence of flowing water on Mars. Scientists have long speculated that Recurring Slope Lineae -- or dark patches -- on Mars were made up of briny water but the new findings prove that those patches are caused by liquid water, which it has established by finding hydrated salts. Several hundred camped outside the London store in Covent Garden. The 6s will have new features like a vastly improved camera and a pressure-sensitive "3D Touch" display

Organisations have begun to shift their analytical efforts to back office operations and away from more customer-facing processes in a search for greater competitive advantage, according to a new report. More than two thirds of companies, based on feedback from 600 operations executives surveyed as part of a report from Capgemini Consulting's digital transformation institute, revealed there is now a greater focus on operational analytics initiatives, in order to boost efficiency behind the scenes. Anne-Laure Thieullent, head of big data, Europe, for Capgemini's insights and data global practice, said: "Organisations are pivoting towards operational analytics as it can both increase the efficiency and performance of the back office as well as boost the customer experience in the front office. However, despite the focus, there are factors limiting the success of these projects; specifically siloed datasets, fragile governance models, inability to harness third party data sources, and an absence of a strong mandate from leadership teams." The four levels of maturity for operational analytics, as decided by Capgemini Consulting, are'Game Changers' - those who have both integrated analytics and realised its benefits, 'Optimisers' - those who have seen basic success but not yet scaled-up efforts, 'Strugglers' - who have adopted the analytics strategy without seeing the benefits, and'Laggards' - who are just beginning to focus on operational analytics.

Somewhere in a Cupertino warehouse, a giant labors with robotic precision, its 29 arms singularly focused on one thing: an iPhone. But instead of putting pieces together, this robot is pulling pieces apart. It disassembles iPhones at the rate of one handset every 11 seconds--less time than it takes you to fish your phone out of an overcrowded bag. Apple calls the machine Liam. The project was kept secret for three years, says Mashable deputy tech editor Samantha Murphy Kelly, who was allowed a sneak preview of Liam in action.

The video game industry has already taken 2016 by storm. With San Francisco's annual Game Developers Conference seeing record numbers of attendees, and Ubisoft's The Division becoming the fastest-selling original IP in games history – and generating 300m in the process – there's good reason to be excited if you're a video game fan. If first-person shooters are not your cup of tea, there's Stardew Valley, a new role-playing adventure game that allows you to go fishing, plant seeds and fall in love. Joining co-hosts Keith Stuart and Jordan Erica Webber are the founder of UK-based studio Fourth State, Mark Backler, and the community manager at Chucklefish, Molly Carroll.