Ethereum in practice part 2: how to build a better democracy in under a 100 lines of code

This is a second post on a series on how to use the current Ethereum tools to build smart contracts without needing programming experience. Download the latest version of the Ethereum Wallet, read the first part and let’s have fun! Creating a token is fun, but what is the value of a token that doesn’t do anything new? We are now going to create a new contract that uses the tokens we just created. The contract will be a Democratic organization... [Read More]

Ethereum in practice part 1: how to build your own cryptocurrency without touching a line of code

A lot of things have happened in the past few weeks in the Ethereum ecosystem, so many that it might be hard for a casual observer to understand where we are and what’s available out there. So I would like to use my first post here to give you an overview of the tools we’ve built and how you can use them to build interesting things right now. But first a short introduction: I am Alex Van de Sande and... [Read More]

Applications of Security Deposits and Prediction Markets You Might Not Have Thought About

Special thanks to Vlad Zamfir for his work in developing many of the ideas behind prediction markets for content curation. For the past six years, people have been searching to try to find those elusive applications of blockchain technology that could finally break out into the mainstream. For cryptocurrency, the applications are largely already known - though it of course remains to be seen just how well it will be able to retain its advantages as traditional payment systems continue... [Read More]

Merkling in Ethereum

Merkle trees are a fundamental part of what makes blockchains tick. Although it is definitely theoretically possible to make a blockchain without Merkle trees, simply by creating giant block headers that directly contain every transaction, doing so poses large scalability challenges that arguably puts the ability to trustlessly use blockchains out of the reach of all but the most powerful computers in the long term. Thanks to Merkle trees, it is possible to build Ethereum nodes that run on all... [Read More]

Stateful Turing-Complete Policies

One of the major security challenges of the internet over the last twenty years has consistently been the rather simple problem of securing user accounts. Right now, users have accounts with hundreds of websites, and dozens of passwords, leading to large numbers of hacks as individual websites, often run by people not particularly skilled in the finer points of cryptography and internet security, find themselves exploited by increasingly clever hackers, and users frequently deal with the complexity of remembering hundreds... [Read More]

Ethereum Dev Update 2015 / Week 44

With DEVCON1 a mere week away, the teams are excited and preparing to share all the great tools and technology the ecosystem has to offer. There will be hundreds of developers and dozens of talks including Nick Szabo, Vitalik Buterin, and Marley Gray from Microsoft. Tickets are limited and we anticipate selling out, so if you haven’t already registered, head on over to to secure your spot now! cpp-ethereum TurboEthereum released 1.0.0 of the C++ tools. Work has been... [Read More]

Microsoft to Sponsor Ethereum’s DEVCON1

London, United Kingdom, October 28th - Ethereum is happy to announce that Microsoft will sponsor and attend DΞVCON1, the premier Ethereum developer conference. Marley Gray, Director of Technology Strategy US Financial Services at Microsoft said, “Microsoft is excited to sponsor and attend Ethereum’s DevCon1. We find the Ethereum blockchain incredibly powerful and look forward to collaborating within the Ethereum Community. We see a future where the combination of Microsoft Azure and Ethereum can enable new innovative platforms like Blockchain-as-a-Service. This... [Read More]

Nick Szabo Confirmed as Keynote Speaker of Ethereum’s DEVCON1

London, United Kingdom, October 22nd - The Ethereum Foundation is pleased to announce the Keynote Speaker of Ethereum’s annual conference DΞVCON1, Nick Szabo. Nick’s keynote will focus on the history of the blockchain, smart contracts and assets on the blockchain. Nick is a computer scientist, legal scholar and cryptographer known for his research on digital contracts and digital currency. The phrase and concept of “smart contracts” was developed by Szabo with the intent of merging contract law into programming protocols... [Read More]

Security alert [Implementation of BLOCKHASH instruction in C++ and Go clients can potentially cause consensus issue – Fixed. Please update.]

Summary: Erroneous implementation of BLOCKHASH can trigger a chain reorganisation leading to consensus problems Affected configurations: All geth versions up to 1.1.3 and 1.2.2. All eth versions prior to 1.0.0. Likelihood: Low Severity: Medium Impact: Medium Details: Both C++ (eth) and Go (geth) clients have an erroneous implementation of an edge case in the Ethereum virtual machine, specifically which chain the BLOCKHASH instruction uses for retrieving a block hash. This edge case is very unlikely to happen on a live... [Read More]

Vitalik’s Research and Ecosystem Update

Over the last five days, myself, our executive director Ming Chan, and several others from the Ethereum team and Ethereum-based projects and businesses including Maker, String/Dfinity and Consensys have been visiting China and Hong Kong, where there have been a series of back-to-back conferences and events most notably including the Blockchain Workshop in Hong Kong on Oct 11-13 and the “First Global Blockchain Summit” in Shanghai organized by our friends at Wanxiang on Oct 15-16, while at the same time... [Read More]