Edit: updated for 2019! Ethereum’s October 15th 2017 hardfork introduced some cryptography precompiles, so now you can do more fancy privacy friendly things. However, it’s a bit tricky using precompiles if you don’t know how to call them, and get all of that low-gas-consuming goodness for yourself. So I’ll explain. inline assembly? The evm? Precompiles? Solidity??? …

A few days ago Multichain’s users were hacked by several attackers groups, all abusing the same vulnerability in Multichain (previously AnySwap) smart contract. The attackers were able to steal tokens valued at millions of US Dollars. Crypto Protocol Publicly Announces Flaw, Users Relentlessly Owned by Hackers The hack against users of Multichain is getting worse as a cybersecurity researcher calls the incident "the worst way…www.vice.com

Explaining Ethereum state trie to deepen knowledge of Ethereum blockchain. Introduction This article explains the Ethereum state trie. Ethereum is often called “world state machine” and uses original data storage to record states(accounts) and transactions. As state trie is a core database in Ethereum, it is important to understand it to…

According to the most recent developer report by Alchemy, the Web3 environment just reached more than 12.000 dApps running across all chains, and, along with that, the number of Smart Contracts verified has grown at least 160% YoY. …

Free stuff is always a good thing! Even if the web2 products are selling our data without our consent, we are comfortable in using them, because they won’t charge us. Almost every interaction with the dApp involves a transaction which seems pretty complicated and intimidating for beginners because it prompts…

The web needs a better business model — and we believe the technology is finally here to do it. — It’s become dangerously clear in the last few years that the business model we thought would support a vibrant, open web just isn’t going to work any more. …

We often hear about major attacks conducted against projects that have failed to get a smart contract audit. You know the story: headlines with eye-watering numbers, a once promising project now relegated to history, the usual narratives peddled about the ‘wild west’ of crypto. …

One of the greatest features of the blockchain is that data are immutable. That means that nobody can change the content of any transaction without invalidating the whole blockchain. But unfortunately, there are several issues with this system: When you deploy your smart contract, you can’t change the code afterwards…

EIP-1271 defines a way to verify signatures through a smart contract, these are usually multi-signature (multisig) wallets like Gnosis Safe, unfortunately, some websites, like OpenSea don’t like multisig wallets, or don’t want to allow multisig wallets to log in, even though it is simple and safe. So in this post…

I migrated my posts to my own blog because Medium is becoming less and less comfortable for readers (paywalls, impossibility to highlight the code, etc.). To read this article in a nicer and privacy friendly context, read it on my personal blog and follow me on Twitter to get notified! …

We need an efficient structure to store a large number of entries in a smart contract that we can quickly traverse. It must also be very cheap to add new items, even as the amount of items grows. The mapping data type in solidity is wonderful for storing information, but…

The idea behind Relic is simple: smart contracts should be able to securely access any data ever pushed to Ethereum. After all, we can easily access the history on Etherscan, or with our own archive node, so why not from dApps? While the basic idea is simple, there’s a lot…

tl;dr There is a critical bug in a lot of ERC20 token contracts that surfaced due to a recent Solidity update. ERC Basics The ERC20 standard is by far the most common token standard on the Ethereum platform. ERC20 is defined as an interface that specifies which functions and events…

by Zoraiz Mahmood — Twitter @0xZorz — Transparent Proxy, Eternal Storage, Diamond Storage, Multi-facets. One may come across these terms when trying to build high quality contracts that can stand the test of time, upgrading as required. This summary aims to break them down, how they interact with each other and how you can get started using…

A few weeks ago I published the article ‘What to Build Next? — According to Vitalik’ Thank you for the viewership. It means a lot and helps motivate me to continue. The years spent as a web developer and programming mentor haven’t gone to waste. …

One of the greatest features of the blockchain is that data are immutable. That means that nobody can change the content of any transaction without invalidating the whole blockchain. But unfortunately, there are several issues with this system: When you deploy your smart contract, you can’t change the code afterwards…