Dec 15, 2021Building a secure NFT gaming experience. A Herdsman’s diaryExperiences and learnings from my continuous security audit for Wolf Game. The Shepherd never loses a beat. Mere hours after the Great Rescue of 13,809 wolves and sheep, the nimble Shepherd had already specced the next stages of the game and was writing code at the speed of light. After…Ethereum7 min readEthereum7 min read
Nov 28, 2021Wolf Game Herdsman’s reportThe Great Rescue of 13,809 sheep and wolves. On November 22th, notstoops reported a reentrancy issue in Wolf Game that would have allowed malicious users to mint arbitrary amounts of WOOL. In response, the Shepherd paused the Barn (staking) smart contract. …Ethereum4 min readEthereum4 min read
Aug 8, 2021Rage of the machine: An AI* makes metal musicIntroducing the latest album by the versatile metal genius DeepSlayerXL, with song reviews by GPT-3. *Apologies to ML researchers for saying “AI” in the title, the article was written for a general audience. As a teenager, I played in a small-town metal band. This was the nineties so our music…Deep Learning5 min readDeep Learning5 min read
Jun 18, 2021Is Tether a black swan?A risk assessment by a DeFi security dude. Note: I’ve been working as a security auditor and engineer in the blockchain space for four years and participated in audits of DeFi protocols such as Aave, Bancor and mStable which also involved assessing economic risk. …Cryptocurrency14 min readCryptocurrency14 min read
Nov 24, 2020I asked GPT-3 for the question to “42”. I didn’t like its answer and neither will you.Can GPT-3 compute the ultimate question about life, the Universe, and everything? Ironically, even though I didn’t like its response, it did eventually lead to a potential answer to the ultimate question. It is known that the answer to life, the Universe, and everything is 42. However, despite the concerted…AI6 min readAI6 min read
Mar 24, 2020Catching weird security bugs in Solidity smart contracts with global invariant checksContract invariants are properties of the program program state that are expected to always be true. In my previous article I discussed the use of Solidity assertions to check contract invariants. This article expands on the use of invariants and provides a couple of additional examples. An interesting property of…Solidity7 min readSolidity7 min read
Published inCoinmonks·Jan 28, 2020How to become a cryptocurrency thought leader on TwitterThought leading is a complicated profession. Thanks to the emergence of cryptocurrency, it has also been one of the fastest growing fields of the past decade. This article outlines simple rules to get you started on this rewarding career path. It doesn’t reflect the opinion of my employer. The most…Cryptocurrency6 min readCryptocurrency6 min read
Published inCoinmonks·Jan 28, 2020Advanced smart contract security verification in RemixThe Remix development environment provides users with a convenient and powerful way of checking the correctness of smart contracts via the MythX plugin. In this article, I’ll explain the basics and provide several examples including security tests of real-world smart contracts. Smart contracts are immutable (or at least supposedly so)…Blockchain11 min readBlockchain11 min read
Published inGood Audience·May 12, 2019Blockchain? Bah!Why the cryptocurrency experiment has failed. I shouldn’t have to write it but this article is satire. After one decade of blockchain, I’m perplexed. It’s not that I haven’t had a gas of a good time on Crypto Twitter. I’ve met great people and even caught a pump or two…Blockchain3 min readBlockchain3 min read
Published inConsenSys Diligence·Mar 29, 2019Ethereum security tools built by ConsenSys DiligenceConsenSys Diligence is a security-focused group of 30+ Ethereum engineers, auditors and researchers distributed all over the world. We have a tradition of building security tools for ourselves and the Ethereum community. Because our time is precious, we focus on creating polished, highly usable tools that are truly helpful to…Ethereum4 min readEthereum4 min read
