I Almost Hashed a Document Number That Needed to Be Read Again (opens in new tab)

What building KYC verification taught me about the difference between encryption and hashing - and why getting that choice wrong would have broken the entire feature VaultPay is a wallet microservice I built on top of AuthShield. Previous parts: Part 1 is here: Part 2 is here: Part 3 is here: Part 4 is here: When I started designing KYC verification for VaultPay, my first instinct was to hash the document number before storing it. Hashing felt like the secure choice. It's what you do with pas...