Recent content in My experience on Gustavo Grieco: blockchain security researcher
TL;DR We proved the core accounting math of Spark’s PSM3 (share price, conversions, swap quotes) against the real bytecode: sixty properties, verified for every input up to uint128 , with all the code in our spark-psm branch . The proofs run in Echidna’s verification mode on top of hevm’s arithmetic abstraction, still experimental and in review as argotorg/hevm#1075 . What…
In this post, we will see a bit of the new Echidna capabilities using the enhanced symbolic execution from hevm. In a nutshell, symbolic execution works in the same way as fuzzing, checking whether a program has specific issues, like assertion failures . However, unlike fuzzing, it either confirms the program works correctly by showing no paths lead to these issues, or it finds examples that prove…
Over the last couple of weeks, I’ve been working on prototyping a new open-source tool called Quimera . Quimera was born out of my deep interest in automatic exploit generation, the recent advancements in LLM reasoning, and, frankly, a lot of free time. The core idea behind Quimera is to use feedback-driven exploit generation for Ethereum smart contracts, leveraging LLMs and Foundry traces.…
Security Stuff Recent Working on a prototype for usig LLMs for automatic exploit generation in EVM: quimera : data-driven exploit generation for Ethereum smart contracts using LLMs and Foundry. Worked on some of the most influential smart contract fuzzers for EVM: Led the development of echidna . Provided assistance on the medusa development. Also have some experience with symbolic execution:…
Most important academic papers Slither: A Static Analysis Framework for Smart Contracts (Josselin Feist, Gustavo Grieco , Alex Groce) Manticore: A User-Friendly Symbolic Execution Framework for Binaries and Smart Contracts (Mark Mossberg, Felipe Manzano, Eric Hennenfent, Alex Groce, Gustavo Grieco , Josselin Feist) SMARTIAN: Enhancing Smart Contract Fuzzing with Static and Dynamic Data-Flow…
Only a small part of the audits where I was involved was published. This is the current list of public audits: Arbitrum (2020-2025) Reviewed all the major components: Nitro/ArbOS ( 1 , 2 , 3 , 4 ) Stylus ( 1 , 2 ) BoLD ( 1 , 2 , 3 ) Bridge ( 1 , 2 , 3 , 4 ) Timeboost ( 1 ) Sequencer ( 1 ) Security Council: ( 1 ) Governance actions: ( 1 , 2 , 3 , 4 ) 2025 ZkVerify 2023 Nested Finance Atlendis…