A gentle introduction to interbank payment systems

How do banks pay each other?  In most countries, when banks want to transfer money to each other, perhaps upon instruction from a customer, they don’t put bundles of banknotes in vans, they pay each other digitally.  How does this work?

This post is intended as a primer about payment systems and explains correspondent banking, nostros, real time gross settlement (RTGS) systems and deferred net settlement (DNS) systems.  It supports other posts where I discuss decentralisation of these systems using distributed ledgers.

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A gentle introduction to self-sovereign identity

In May 2017, the Indian Centre for Internet and Society think tank published a report detailing the ways in which India’s national identity database (Aadhaar) is leaking potentially compromising personal information. The information relates to over 130 million Indian nationals.  The leaks create a great opportunity for financial fraud, and cause irreversible harm to the privacy of the individuals concerned.

It is clear that the central identity repository model has deficiencies.  This post describes a new paradigm for managing our digital identities: se
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A gentle introduction to The Hyperledger Project

I have noticed a great deal of confusion when people talk about “Hyperledger”.  I recently gave a talk about this at a meetup hosted in Paypal’s offices in Singapore.  This article summarises the talk.

Hyperledger is a project, not a technology, and you don’t build stuff on Hyperledger.

When people ask, “What is Hyperledger?”, the answer I give is usually “Do you mean the project called Hyperledger run by The Linux Foundation, or do you mean one of the ledger technologies incubated by that project which used to be confusingly called Hyperledger Fabric?”. The first is a group of people, the second other is a bunch of code.

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A gentle introduction to Ethereum

Introduction

Ethereum builds on blockchain and cryptocurrency concepts, so if you are not familiar with these, it’s worth reading a gentle introduction to bitcoin and a gentle introduction to blockchain technology first. This article assumes the reader has a basic familiarity with how Bitcoin works.

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On loyalty point schemes and blockchains

Over the past year I’ve been asked my thoughts about ‘loyalty points on blockchains’ many times. The thinking seems to be bitcoin -> digital currency -> digital tokens -> loyalty points and at first pass it feels like a natural extension of a theme. People read about cryptocurrency trading and interoperability then think “Wouldn’t it be really cool if I could exchange my loyalty points for other ones, or if I could buy and sell them with real money?”.

This post attempts to describe how I understand the purpose of loyalty points, and in this context, how applicable blockchains are as a technical solution.

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A gentle introduction to immutability of blockchains

In the context of data security, the immutability of data stored on blockchains is important. What do people mean when they say “Blockchains are immutable”? In this post I try to explain the key concepts.

It may be useful to read introductions to blockchains and Bitcoin if you have just arrived here or are unfamiliar with them.

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A gentle introduction to smart contracts

What are people talking about when they talk about smart contracts?

In the context of blockchains and cryptocurrencies, smart contracts are:
pre-written logic (computer code),
stored and replicated on a distributed storage platform (eg a blockchain),
executed/run by a network of computers (usually the same ones running the blockchain),
and can result in ledger updates (cryptocurrency payments, etc).

… In other words, they are little programs that execute “if this happens then do that”, run and verified by many computers to ensure trustworthiness.

If blockchains give us distributed trustworthy storage, then smart contracts give us distributed trustworthy calculations.

Smart contracts are one of the functionalities that sets Ethereum apart from other blockchains.

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A gentle introduction to digital tokens

Digital tokens have come to the fore recently, firstly with excitement about cryptocurrencies such as bitcoin, then with digital tokens being used to represent different assets on a blockchain.  What are they?  How can you digitise a token?  Why is it important?

When I hear the word ‘token’ I think of round plastic things like a casino chip, or something which I can use to exchange for a beer under a specific system or in a specific marketplace.

tokens
My idea of tokens.

We will explore the original usage of the phrase ‘digital token’, then take a look into the world of cryptocurrency tokens, differentiating between blockchain-native tokens like BTC on Bitcoin or ETH on Ethereum, and asset-backed tokens like IOUs on Ripple.

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