Blockchain

Celebrating our 2023 open-source contributions

At Trail of Bits, we pride ourselves on making our best tools open source, such as Slither, PolyTracker, and RPC Investigator. But while this post is about open source, it’s not about our tools… In 2023, our employees submitted over 450 pull requests (PRs) that were merged into non-Trail of Bits repositories. This demonstrates our […]

Billion times emptiness

Max Ammann
Behind Ethereum’s powerful blockchain technology lies a lesser-known challenge that blockchain developers face: the intricacies of writing robust Ethereum ABI (Application Binary Interface) parsers. Ethereum’s ABI is critical to the blockchain’s infrastructure, enabling seamless interactions between smart contracts and external applications. The complexity of data types and the need for precise encoding […]

Introducing invariant development as a service

Trail of Bits
Understanding and rigorously testing system invariants are essential aspects of developing robust smart contracts. Invariants are facts about the protocol that should remain true no matter what happens. Defining and testing these invariants allows developers to prevent the introduction of bugs and make their code more robust in the long term. However, it is difficult […]

Can you pass the Rekt test?

Trail of Bits
One of the biggest challenges for blockchain developers is objectively assessing their security posture and measuring how it progresses. To address this issue, a working group of Web3 security experts, led by Trail of Bits CEO Dan Guido, met earlier this year to create a simple test for profiling the security of blockchain teams. We […]

Fuzzing on-chain contracts with Echidna

Elvis Skozdopolj, Guillermo Larregay
With the release of version 2.1.0 of Echidna, our fuzzing tool for Ethereum smart contracts, we’ve introduced new features for direct retrieval of on-chain data, such as contract code and storage slot values. This data can be used to fuzz deployed contracts in their on-chain state or to test […]

Evaluating blockchain security maturity

Josselin Feist, Blockchain Engineering Director
Holistic security reviews should reveal far more than simple bugs. Often, these bugs indicate deeper issues that can be challenging to understand and address. Given the time-boxed nature of reviews, security engineers may not have the opportunity to identify all bugs caused by these problems—and they may continue to […]

What we told the CFTC about blockchain threats

Trail of Bits
Dan Guido, CEO In March, I joined the Commodity Futures Trading Commission’s Technology Advisory Committee (TAC), helping the regulatory agency navigate the complexities of cybersecurity risks, particularly in emerging technologies like AI and blockchain. During the committee’s first meeting, I discussed how the rapidly changing and public nature of blockchain technology makes it uniquely susceptible […]

Differential fuzz testing upgradeable smart contracts with Diffusc

Trail of Bits
On March 28, 2023, SafeMoon, a self-styled “community-focused DeFi token” on Binance Smart Chain, lost the equivalent of $8.9 million in Binance Coin BNB to an exploit in a liquidity pool. The exploit leveraged a simple error introduced in an upgrade to SafeMoon’s SFM token contract, allowing the attacker to burn tokens held in the […]

What should governments consider when getting involved with blockchain?

Trail of Bits
Last September, Principal Security Engineer Dr. Evan Sultanik was on a panel hosted by the Naval Postgraduate School’s Distributed Consensus: Blockchain & Beyond (DC:BB) movement, where faculty and students there are seeking opportunities to learn and share knowledge, research, funding, and events focused on distributed consensus technologies. The panel of nine government, academia, and industry […]

Circomspect has more passes!

Fredrik Dahlgren
TL;DR: We have released version 0.8.0 of Circomspect, our static analyzer and linter for Circom. Since our initial release of Circomspect in September 2022, we have added five new analysis passes, support for tags, tuples, and anonymous components, links to in-depth descriptions of each identified issue, and squashed a […]

Reusable properties for Ethereum contracts

Trail of Bits
As smart contract security constantly evolves, property-based fuzzing has become a go-to technique for developers and security engineers. This technique relies on the creation of code properties – often called invariants – which describe what the code is supposed to do. To help the community define properties, we are releasing a set of 168 pre-built […]

It pays to be Circomspect

Fredrik Dahlgren
In October 2019, a security researcher found a devastating vulnerability in Tornado.cash, a decentralized, non-custodial mixer on the Ethereum network. Tornado.cash uses zero-knowledge proofs (ZKPs) to allow its users to privately deposit and withdraw funds. The proofs are supposed to guarantee that each withdrawal can be matched against a […]