During the last month and a half, the Ethereum core development and research teams have been building upon the progress made in the last year, and with the specter of last year's security issues now well behind us, work has begun in full force on imple...

Members of the Ethereum R&D team and the Zcash Company are collaborating on a research project addressing the combination of programmability and privacy in blockchains. This joint post is being concurrently posted on the Zcash blog, and is coauthor...

The first version of the Light Ethereum Subprotocol (LES/1) and its implementation in Geth are still in an experimental stage, but they are expected to reach a more mature state in a few months where the basic functions will perform reliably. The light...

December marks a month of continued progress in the Ethereum ecosystem. Research on proof of stake and sharding continues after the research team's workshop in Singapore in November, the light client slowly keeps getting better, Whisper and Swarm keep ...

On December 16, we were made aware that someone had recently gained unauthorized access to a database from forum.ethereum.org. We immediately launched a thorough investigation to determine the origin, nature, and scope of this incident. Here is what we...

With the long awaited geth 1.5 ("let there bee light") release, Swarm made it into the official go-ethereum release as an experimental feature. The current version of the code is POC 0.2 RC5 -- "embrace your daemons" (roadmap), which is the refactored ...

This chapter describes the game theory and economic security modelling we were doing in the Fall of 2014. It recounts how the "bribing attacker model" led our research directly to a radical solution to the long range attack problem....

Vitalik suggested last week that I share my basic research and design philosophy in a blog post, I agreed but complained that it was still changing. My friend Jon West told me that everyone would really appreciate it if I told everyone about my Casper ...

The possibilities of zkSNARKs are impressive, you can verify the correctness of computations without having to execute them and you will not even learn what was executed - just that it was done correctly. Unfortunately, most explanations of zkSNARKs re...

This week marks the completion of our fourth hard fork, Spurious Dragon, and the subsequent state clearing process, the final steps in the two-hard-fork solution to the recent Ethereum denial of service attacks that slowed down the network in September...

Security Alert Affected configurations: Geth Severity: High Summary:  An issue has been identified with Geth's journaling mechanism. This caused a network fork at block #2686351 (Nov-24-2016 14:12:07 UTC). The...

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The Ethereum network will be undergoing a hard fork at block number 2,675,000, which will likely occur between 15:00 and 16:00 UTC on Tuesday, November 22, 2016. A countdown timer can be seen at https://fork.codetract.io/. The Morden test network will ...

The Go Ethereum team is very proud to finally release Geth 1.5, which can almost be called a complete internal rewrite of the Go Ethereum (go-ethereum) codebase. We've packed a huge number of changes into this release, and simply listing them wouldn't...

This blog post provides an update on our findings following the discovery of the storage corruption bug last week. In summary, the bug was much less severe than we initially thought. The small number of affected contracts we found is either only exploi...

Summary: In some situations, variables can overwrite other variables in storage. Affected Solidity compiler versions: 0.1.6 to 0.4.3 (including 0.4.4 pre-release versions) Detailed description: Storage variables that are smaller than 256 bits are pa...

One of the important indicators of how much load the Ethereum blockchain can safely handle is how the uncle rate responds to the gas usage of a transaction. In all blockchains of the Satoshian proof-of-work variety, any block that is published has the ...

Mist leaks some low level APIs, which Dapps could use to gain access to the computer's file system and read/delete files. This would only affect you if you navigate to an untrusted Dapp that knows about these vulnerabilities and specifically tries to a...

The Ethereum network will be undergoing a hard fork at block number 2463000, which will likely occur between 12:00 and 13:00 UTC on Tuesday, October 18, 2016. A countdown timer can be seen at https://fork.codetract.io/....

During the last couple of weeks, the Ethereum network has been the target of a sustained attack. The attacker(s) have been very crafty in locating vulnerabilities in the client implementations as well as the protocol specification. While the recent pa...

Today the network was attacked by a transaction spam attack that repeatedly called the EXTCODESIZE opcode (see trace sample here), thereby creating blocks that take up to 20-60 seconds to validate due to the 50,000 disk fetches needed to process the tr...

URGENT ALL MINERS: The network is under attack. The attack is a computational DDoS, ie. miners and nodes need to spend a very long time processing some blocks. This is due to the EXTCODESIZE opcode, which has a fairly low gasprice but which requires no...

Security Alert Affected configurations: Geth Likelihood: High Severity: High Summary: geth nodes running out of memory and crashing on block https://etherchain.org/block/2283416 Details: TBD Solution: [Geth 1.4.12](http...

Today, I am delighted to announce that Yoichi Hirai (pirapira on github) is joining the Ethereum project as a formal verification engineer. He holds a PhD from the University of Tokyo on the topic of formalizing communicating parallel processes and cre...

The primary expense that must be paid by a blockchain is that of security. The blockchain must pay miners or validators to economically participate in its consensus protocol, whether proof of work or proof of stake, and this inevitably incurs some cost...

The foundation has committed to support the community consensus on the admittedly difficult hard fork decision. Seeing the results of various metrics, including carbonvote, dapp and ecosystem infrastructure adoption, this means that we will focus our r...

The DAO soft-fork attempt was difficult. Not only did it turn out that we underestimated the side effects on the consensus protocol (i.e. DoS vulnerability), but we also managed to introduce a data race into the rushed implementation that was a ticking...

We would like to congratulate the Ethereum community on a successfully completed hard fork. Block 1920000 contained the execution of an irregular state change which transferred ~12 million ETH from the "Dark DAO" and "Whitehat DAO" contracts into the W...

The DAO, though not a product developed by the Ethereum Foundation, has been a hot topic as of late, both internally in the organisation as well as within our community. The Hard Fork is a delicate topic and the way we see it, no decision is the right ...

Ethereum is not meant to be a platform to build esoteric smart contract applications that require a STEM degree to understand, but it aims to be one pillar of a different architecture for applications on the world wide web. With this post we will try t...