Prototypes Nordlys FysioterapiP4 · Encrypted form
Answers
The clinic’s inbox

Answers only you can open

This page is the receiver. It made a key pair and keeps the private key in this browser. The form link has the public key after the #, so the key never reaches a server log. Whoever fills in the form encrypts the answers with that key before they are sent.

PartValue
Your keyMaking a key
Method
Answers on the server0

What the server holds

The server in this prototype is the browser’s local storage. The list below shows every envelope exactly as it is stored.

JSON
[]
How Nordlys Fysioterapi is built
  1. The form makes a new key pair for this one answer.
  2. It combines its private key with the clinic’s public key. HKDF turns the result into an AES-GCM key.
  3. The answers are encrypted with that key. The envelope holds the form’s public key, the salt, the nonce and the ciphertext.
  4. The form’s private key is thrown away. After sending, not even this browser can open the answers again.