Echidna Streaming Workshop

Welcome to the 6-part series on how to use Echidna to fuzz like a pro! This repository has 6 folders, each of which maps to a specific workshop in the series.

To learn more about how these workshops will work, please read this blogpost.

Note that each workshop will be live streamed on Trail of Bits' Twitch channel and YouTube channel at 12 PM EST on the following days:

Beginner

Part 1: The Basics (streaming on Nov 16, 2022)

Part 2: Fuzzing arithmetics and functions (streaming on Nov 22, 2022)

Intermediate

Part 3: Introduction to AMM’s invariants (streaming on Nov 30, 2022)

Part 4: AMM fuzzing (streaming on Dec 6, 2022)

Advanced

Part 5: Introduction to advanced DeFi’s invariants (streaming on Dec 14, 2022)

Part 6: Advanced DeFi invariants (streaming on Dec 21, 2022)

Additional Notes

• This repository will be migrated to the building-secure-contracts repository at the end of the series. We will update this README when that time comes.
• This repository will be updated as the series continues. Thus, there might be some incomplete folders / broken links in the process.

Try your own invariants!

ABDK Math

• Associative property of multiplication – (x * y) * z = x * (y * z)
• Distributive property of multiplication – x * (y + z) = (x * y) + (x * z)
• Multiplication of inverses (using the inv function) – inv(x * y) = inv(x) * inv(y)
• Square roots – sqrt(x) * sqrt(x) = x
• Logarithms – log2(x * y) = log2(x) * log2(y)
• Average gavg()
• Power pow()
• Natural logarithm – ln()
• Exponentiation – exp()

Uniswap V2

• Path independence for swaps
• Pool invariant always increases
• LP tokens are minted differently based on existing pool liquidity
• An LP provider's underlying asset balances are monotonically increasing
• Path independence for LPs

Echidna Installation

• Download relevant binaries for your system
• Add to PATH* (All commands in respective README documents assume echidna-test refers to the binary)