Some useful bits: A few solved development problems via Crypto
summary
Covers concrete fixes: use private set intersection (Diffie‑Hellman and newer PSI/OPRFs) to join IDs without sharing emails, use secure multi‑party computation or homomorphic encryption to compute across parties (tradeoffs: SMPC is network‑heavy, HE is CPU‑heavy), and use the Signal Protocol (ratchet + periodic Diffie‑Hellman resets) for end‑to‑end messaging. Mentions Google’s Private Join and CipherMode’s open‑source Rust SMPC with Python bindings, warns against rolling your own and advises audited libraries and combining with differential privacy.
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chapters (11)
- 0:00Start
- 5:07Google Ads Problem
- 8:40Diffie-Hellman Key Exchange Finding Private Joins with Shared Keys
- 11:55Private Set Intersection
- 15:19Yao's MBillionaires Problem
- 16:03Secure Multi-Party Computation (SMPC) Cryptography for multiple parties/players
- 22:41Signal Chat: End-to-End Encryption
- 23:35What a Rachet!
- 25:51Double Rachet Algorithm Securing past and future messages
- 27:22End-to-end Encryption Secure messaging & data sharing
- 29:12Today was just a taste!
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