--- title: Tutorial: Introduction to Formal Verification with Lean... description: A hands-on tutorial introducing formal verification using the Lean 4 proof assistant, targeted at cryptographic engineers. It walks through defining BitStrings... canonical: https://daily.dev/posts/tutorial-introduction-to-formal-verification-with-lean-part-1--blrhdrqdt twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Tutorial: Introduction to Formal Verification with Lean (Part 1) | daily.dev og:description: A hands-on tutorial introducing formal verification using the Lean 4 proof assistant, targeted at cryptographic engineers. It walks through defining BitStrings... og:url: https://daily.dev/posts/tutorial-introduction-to-formal-verification-with-lean-part-1--blrhdrqdt og:image: https://api.daily.dev/og/posts/bLrHdRqDT.png og:image:alt: Tutorial: Introduction to Formal Verification with Lean (Part 1) og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Tutorial: Introduction to Formal Verification with Lean (Part 1) **[Hacker News](https://daily.dev/sources/hn)** · 26 min read · 0 upvotes · 0 comments ## Summary A hands-on tutorial introducing formal verification using the Lean 4 proof assistant, targeted at cryptographic engineers. It walks through defining BitStrings and XOR over ℤ₂, proving XOR properties (commutativity, associativity, identity, self-inverse) using Lean tactics, defining a Shannon Cipher as a Lean structure, and finally proving that the One-Time Pad satisfies the Shannon Cipher correctness property. Key Lean concepts covered include implicit parameters, currying, lambda functions, simp tactics, Vector.ext, and namespaces. The tutorial follows Boneh & Shoup's 'A Graduate Course in Applied Cryptography' as its mathematical source. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [From Zero to QED](https://daily.dev/posts/from-zero-to-qed-h3omgvjou) · Hacker News · 2 upvotes · 0 comments - [Introduction to Lean for Programmers](https://daily.dev/posts/introduction-to-lean-for-programmers-zyd84tuax) · Towards Data Science · 0 upvotes · 0 comments - [Creator of Lean: Handwritten Math Will Change Dramatically](https://daily.dev/posts/creator-of-lean-handwritten-math-will-change-dramatically-ssexcp90l) · The Developing Dev · 0 upvotes · 0 comments - ["Why not just use Lean?"](https://daily.dev/posts/why-not-just-use-lean--5cqfy7h3y) · Hacker News · 0 upvotes · 0 comments --- Tags: [#cryptography](https://daily.dev/tags/cryptography) [View this post on daily.dev](https://daily.dev/posts/tutorial-introduction-to-formal-verification-with-lean-part-1--blrhdrqdt) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Tutorial: Introduction to Formal Verification with Lean (Part 1)","url":"https://daily.dev/posts/tutorial-introduction-to-formal-verification-with-lean-part-1--blrhdrqdt","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/tutorial-introduction-to-formal-verification-with-lean-part-1--blrhdrqdt"},"datePublished":"2026-07-22T13:04:20.180Z","dateModified":"2026-07-22T13:04:44.778Z","description":"A hands-on tutorial introducing formal verification using the Lean 4 proof assistant, targeted at cryptographic engineers. 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