Encrypted city

Urban metaphors are powerful in the world of computing. The reverse is also true. Computing brings metaphors to bear on how we think of cities — as flows of data, networks, circuits, grids and an Internet of things, as if cities are made up of bits, memories (RAM), sensors, actuators, and with communication systems, inputs,…More

Romancing the blockchain

The blockchain idea is addictive for some. It’s technically fascinating, mysterious and counter-intuitive. It depends on cryptography to function, and inherits the fascination many of us have with cyphers and codes. Who can resist the lure of a secret message? The way blockchain platforms function also mystify with their abstruse methods and terminology: proof of…More

Share city

In his book on the “sharing economy,” Arun Sundararajan maintains that commerce is shifting “away from traditional corporations and toward a crowd of entrepreneurs we find through a digital marketplace” (6). Within the constellation of these new (shared) business models he places Airbnb, a platform that allows individuals to capitalise on their own under-utilised domestic…More

How smart are smart contracts?

Blockchain technologies such as bitcoin, support peer-to-peer monetary transactions, where lines in a shared ledger indicate payer, payee, date, amount and the goods or services to be exchanged: as is the case in a line in a bank statement. But, instead of a text line indicating  the product being exchanged, what if that line included…More

Sign here ……………………

How do signatures function? A signature is a sign, seal, or mark on a document indicating its authenticity, as when a painter signs a painting, or someone signs a letter or legal document. The signature and the thing it marks is meant to be a one-off. The signature marks an original document, before the thing…More

Decode this

Political statements come coded: “I think there’s blame on both sides. I don’t have any doubt about it and you don’t have any doubt about it either.” That was Trump on the white supremacist contingent at the Unite the Right demonstration in Charlottesville this week (with violence resulting in deaths and injury). The statement sounds…More

An anti-hacker puzzle

Following on from my previous post … Here’s a simple puzzle challenge. The SHA256 hashing algorithm (see earlier post: Immutable data) converts any string of text (integers or letters) into a (near) unique 64 character long string of numbers and letters. Using this algorithm the string “301253” (someone’s birthdate) translates to the string of characters…More

Why hackers have to work hard

A 4 digit mechanical combination lock is designed so that a person trying to break into your locker (a padlock hacker) would have to try on average 5,000 combinations (104/2). That’s about 2-5 hours work, which is a big investment in time, and before the hacker exhausts all iterations he or she may well be…More

Immutable data

An application on the exorbin.com website can convert any block of data into a near unique 64 character string of characters. Fun with SHA256 So “abc” converts to ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad My name, “Richard Coyne”, converts to ba7c5c9e90f05540084e798effd0389b60ec98677662017065d34a0b880778a7 Here’s some Shakespeare “To be, or not to be — that is the question: Whether ’tis nobler in the mind to…More

Dark web anonymity

I downloaded a bitcoin wallet to my smartphone on 3 July 2017, and filled it with £100 of bitcoin procured via my debit card. The transaction cost £3. A bank transfer would have been free, but I was in a hurry. (With currency fluctuations, and 3 weeks later, my wallet today contains £110.19. So I…More