I’ve been investigating city life through the lens of cryptography. Here are some of the claims I think I can make on behalf of an “urban cryptography.” The most obvious contribution is that cryptography (digital encryption) addresses and resolves challenges of securing data and information flows in the city. But there’s more. Cities rely on…More
Tag Archives: encryption
Elliptic fields
One property of algebraic equations is that you can perform the same simple arithmetical operation on both sides of the equation and the equivalence still holds for the same x and y values, e.g. y = 2x has the same values if both sides are multiplied by the same number e.g. 6y = 12x. The…More
Sharing a secret number
Here’s a naive method for two people to agree a secret number. The number to be shared is simply an integer, which is a key for some other encrypted communication channel. It could even be a PIN to a bank account, an access code for a door or the combination code to a shared locker…More
Ornament and crime
The Austrian architect Adolf Loos (1870-1933) wrote Ornament and Crime. It is a celebrated polemic against the superfluity of ornament in the modern industrial age: “not only is ornament produced by criminals but also a crime is committed through the fact that ornament inflicts serious injury on people’s health, on the national budget and hence…More
Steganography for architects
Steganography is hiding one picture (a secret or data) inside another (a host or carrier) image. As with cryptography in general, there are several reasons someone might want to hide content in this way. The hidden image could serve as a digital watermark. That’s to assert your claim on a picture. If someone copies it…More
Crypto-sceptics
Encryption is an unfortunate necessity to keep our personal information and communications private. While we ponder whether it’s safe or not to Zoom it’s worth reflecting on encryption’s negatives. Critic Shoshana Zuboff writes “encryption is the only positive action left to discuss when we sit around the dinner table and casually ponder how to hide from…More
Living with virions [and Ro]
Smartphones can’t yet take your temperature and diagnose if you are carrying an infection. But developers are designing smartphone apps to trace if you’ve been in contact with someone who has COVID-19. The most promising contact tracing apps enable smartphones to exchange short encrypted messages when they are within range of one another. That happens…More
Sociable encryption: The secret of the five keys
Will encryption save us? Social psychologist Shoshana Zuboff explains in detail the methods employed by Google and other digital giants to track our clicks, sell our data, and auction targeted advertising slots to monetise our private on-screen experiences. Our online behaviour is the resource. We are the product, not the consumer. Google’s clients are advertisers…More
Hacking the city of the future
What happens when hackers get hacked? The headquarters of the US National Security Agency (NSA) is located between the cities of Washington and Baltimore. Amongst its many operations the NSA develops hacking tools for spying on other countries. But some of these tools leaked out, and earlier this year were turned on the city of…More
No interpreter required
If only people speaking different languages could communicate without the need of an interpreter. I’m thinking of the Trump-Putin encounters with translators present. Only unscrupulous leaders would bar their translators from disclosing to other trusted officials what was said. But I’m also thinking of Leon Battista Alberti’s justification of his cipher technique, which was to…More