Cryptography — ZeroCourse

reading · we frame, you read MIT or the canonical taught · we author, no canonical fits ↺ spirals back to earlier lessons

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Prerequisites

Discrete Mathematics not yet

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reading · 35 min + ~229 min canonical

Symmetric Encryption: Shared Secrets and the AES Workhorse

Cryptography is where security gets its math — the machinery that makes confidentiality and integrity provable rather than hopeful. And it starts with the oldest, most intuitive i…

primary Stanford Cryptography I by Dan Boneh on Coursera

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reading · 35 min + ~229 min canonical L1

Asymmetric Cryptography: The Magic of Public Keys

The previous lesson ended on an apparent impossibility: two strangers want to share a secret key, but everything they send crosses a network an eavesdropper is watching — so how c…

primary Stanford Cryptography I by Dan Boneh on Coursera

after L1 locked

reading · 35 min + ~229 min canonical L1

Hashes, MACs, and Digital Signatures: Integrity and Authenticity

The first two lessons were about confidentiality — keeping messages secret. But secrecy is only half of security, and often not the important half. Consider: a software update dow…

primary Stanford Cryptography I by Dan Boneh on Coursera

after L2 locked

reading · 35 min + ~229 min canonical L1

Putting It Together: TLS, Certificates, and PKI

Every previous lesson gave you a primitive: symmetric encryption (fast, secret, but needs a shared key), asymmetric encryption and Diffie-Hellman (solves key distribution, but slo…

primary Stanford Cryptography I by Dan Boneh on Coursera

after L3 locked

reading · 35 min + ~229 min canonical L1

Key Management and the Frontier: Zero-Knowledge Proofs and Blockchain

The final lesson of Cryptography splits into two very different endings. The first is the humbling operational truth that every practitioner learns: the algorithms are the easy pa…

primary Stanford Cryptography I by Dan Boneh on Coursera

after L4 locked

exercise reading · 15 min L1

Exercises: Easy (Warm-up)

- [ ] Implement Caesar cipher and frequency analysis attack in Ruby — Encrypt/decrypt, break by letter frequency - [ ] Hash a password with bcrypt in Ruby — BCrypt::Password.creat…

after L5 locked

exercise reading · 30 min L1

Exercises: Medium (Core)

- [ ] Implement Diffie-Hellman key exchange in Ruby — Two parties derive shared secret over insecure channel - [ ] Implement HMAC from scratch in Ruby — SHA-256 based, verify mess…

after L6 locked

exercise reading · 45 min L1

Exercises: Hard (Stretch)

- [ ] Implement a simplified TLS handshake in Ruby — Client hello, server hello, key exchange, encrypted communication - [ ] Break a weak hash function — Given MD5 hashes, find co…

after L7 locked

exercise reading · 60 min L1

Mini-Project

- [ ] Build an end-to-end encrypted messaging system in Ruby — Diffie-Hellman key exchange, AES-256-GCM for messages, digital signatures for authentication, perfect forward secrec…

after L8 locked

L10

project reading · 360 min L1

Project: End-to-End Encrypted Chat in Ruby

Build a two-party encrypted messaging system: Diffie-Hellman key exchange (implemented from scratch), AES-256-GCM encryption (via OpenSSL), message signing with HMAC. Two Ruby pro…

after L9 locked

L11

assessment reading · 56 min L1

Self-Assessment: Cryptography

- [ ] What is the difference between symmetric and asymmetric encryption? Give examples of each. - [ ] Explain Diffie-Hellman key exchange. Why can an eavesdropper not derive the …

after L10 locked

11 lessons. Read in order; spiral back when you need to. By the end you'll have used the core ideas twice — once on the abstract, once on something you'll meet at work next week.