HashCloak Launches Formal Verification Tutorial Using Lean
Original: Introduction to Formal Verification with Lean Part 1
Why This Matters
Formal verification of cryptographic protocols reduces the risk of implementation errors in security-critical systems.
HashCloak cryptography engineer Elena published Part 1 of a tutorial series on formal verification using Lean, targeting cryptographic engineers new to the field. The tutorial walks through Lean basics and formally verifies the One-Time Pad (OTP) protocol using definitions from Boneh and Shoup's graduate cryptography textbook.
HashCloak has published a beginner-friendly tutorial series on formal verification using Lean, authored by cryptography engineer Elena. Lean is a functional programming language and theorem prover created in 2013 by Leonardo de Moura at Microsoft Research. It allows mathematical proofs to be written in code and machine-checked by the compiler, ensuring correctness in a way pen-and-paper proofs cannot guarantee.
The tutorial targets cryptographic engineers who are new to formal verification. Part 1 introduces Lean basics and works toward formally verifying the One-Time Pad (OTP) protocol—originally described by Frank Miller and Gilbert Vernam, and later popularized by Claude Shannon. Definitions and proofs are sourced from Dan Boneh and Victor Shoup's 'A Graduate Course in Applied Cryptography.'
HashCloak notes that while resources like VCV-io contain formalized Lean cryptography proofs, they are too advanced for beginners and lack introductory tutorials. This series aims to fill that gap. Recommended supplementary resources include 'The Hitchhiker's Guide to Logical Verification,' 'Functional Programming in Lean,' 'Theorem Proving in Lean 4,' and the browser-based Natural Numbers Game. The full tutorial is structured in four parts, with Part 2 being the most extensive.