Hello, I'm Chris. I'm researching and implementing decentralized technologies.

Here you can find software & hardware I'm working on, and posts I've written on the topic. I'm interested in technology that enables people to control their own data, freedom of expression, web based decentralization, and trust minimised architectures.

Click here for Bugout Box

Technology

Posts

Slingcode: Personal Computing Platform

2020-03-15

Recently I was teaching one of my kids a bit of web coding. This is way more complicated than it should be. There are so many moving parts - configuration, build systems, editors, hosting requirements, certificates etc. just to get a simple web app running. Why?

I thought back to when I was learning to code with my mother on our Apple IIe. The computer was ours. The code was ours. The data was ours.

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The Only Truth Will Be Cryptographic

2020-01-08

Photographs are easy to fake. So much so that there is a turn of phrase to describe it. People say something is "'shopped" when they are skeptical regarding the veracity of an image. This refers to the image editing program Photoshop which is often used to modify images. For example the magazine industry routinely modifies the photographs which appear in their pages.

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A Week in Singapore

2019-11-21

singapore.jpgcyber.jpg

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Announcing The Bugout Box

2019-11-05

A few weeks ago at the BSides Perth conference I announced this piece of hardware I've been tinkering on.

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Speaking schedule 2019 and beyond

2019-09-18

I've got three conference talks coming up in Perth (Australia), London, and The Gold Coast (Australia). If you're nearby let me know - I would love to buy you a coffee/beer and hear what you're up to.

Security BSides

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Notes on "History of the Blockchain" by Nick Szabo

2019-08-28

In November 2015 Nick Szabo gave a talk on the history of the blockchain which was dense with useful ideas.

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BEP44 For Decentralized Applications

2019-05-12

Depiction of decentralized network

In 2014 Arvid Norberg and Steven Siloti came up with a BitTorrent extension called BEP44. The basic purpose of BEP44 is to allow people to store small pieces of information in a part of the BitTorrent network called the DHT. The DHT ("distributed hash table") is a key/value lookup table that is highly decentralized. Prior to BEP44 it was used to look up the IP addresses of peers from the hashes of the torrent they were sharing.

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Build a decentralized web chat in 15 minutes

2019-03-27

This post originally appeared on the David Walsh blog.

In this 15 minute tutorial we're going to build a simple decentralized chat application which runs entirely in a web browser.

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Hashcash Auctions for Decentralized Resource Allocation

2018-10-27

Abstract

Hashcash is a mechanism for defending against spam and denial-of-service attacks in email and other decentralized systems. Implementors of systems using hashcash face the issue of how to set the proof-of-work difficulty. A general solution to this problem is given which can be used to predictably allocate resources in decentralized systems where individual nodes each contribute finite resources. Some emergent effects of this solution are explored.

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Decentralized Identity Linking

2018-08-31

Decentralized identity linking animation

A problem faced by decentralized systems is that of naming things. The problem is best expressed by Zooko's Triangle which conjectured that no single kind of naming system can provide names satisfying all three of the following properties:

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On Self-hosting and Decentralized Software

2018-08-12

Sketch of a tree

Web applications often follow a client-server model meaning that there is a piece of software which runs in your web browser (the client) and a piece of software which runs on a server somewhere. I'm interested in this model, where it came from, and where it's going, and I discuss this below. I'll also discuss a new model for self-hosting web applications that I've been exploring.

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Hash Function Attacks Illustrated

2018-07-30

Here are some illustrated explanations of the main ways in which cryptographic hash functions can be attacked, and be resistant to those attacks.

Zooko Wilcox's blog post Lessons From The History Of Attacks On Secure Hash Functions gives us a nice overview of these and I've quoted his concise explanations below. Check out his great post for more detail and history on this topic.

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Browser Blockchain in ClojureScript

2018-06-13

I built a little blockchain-in-a-browser in ClojureScript to help understand the underlying algorithms.

You can simulate a network of peers by opening multiple browser tabs. Each peer can mine blocks and make transactions independently and the resulting blockchain will resolve conflicts correctly across all tabs.

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3d Printable Sixteen Sided Hexadecimal Die

2014-01-27

Hexadecimal Die

This is a Hexadecimal die that you can 3d print. Download the STL file or get the source code on GitHub. Hopefully useful when generating private keys and the like.

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