updates

Implementation Suggestions

Do access control from a separate secure domain (origin). This provides security and future proofs against domain name changes.

Don't give content hosts secret data. This way they can just restore from backup on break-in instead of having to change all the access control lists. We may even be able to turn this into an authentication integrity check feature?
Derive entity keys instead of randomly generating them. This makes recovery easier (and we can store less data).

Encrypt(
  their public key,
  SHA(my private key + their public key + deterministic string)
)

RELATED: Support subkeys. We need to generate an entity key per-subkey presented.
Support multiple crypto primitives.
Bootstrap off of keybase? Or google's end-to-end: https://github.com/google/end-to-end/wiki/Key-Distribution?
How would I do this with openauth? How many openauth servers would I need?
Replace ACP with xoring + hashing + signing.
Randomize ACP order!

One of the jobs of an AP is to distribute entity keys. How should an AP respond to key requests from unknown parties:
- Generate what would be the key? This means the AP must know enough secret state to generate the key at runtime (privacy/security concern).
- Generate a random key? Currently, these keys only change when the friend's public key changes so maybe not...
- Respond with encrypted(no key) (allows users to verify that NO content has been shared with them)?

DOCUMENT THIS NOW

Unpack, explain.

IBE: We could give every member of a group a (gid, date) group key but these could be used to track group members. Might as well just certify temporary group keys.
Ring Signature: Group membership isn't anonymous. Doesn't really give us anything over ACP anyways.
Group Signature: Same as ring signature.
Group keys: Permanent. Would have to update ACLs to change.
Per service group lists: makes fingerprinting way to easy.
Explain stupid kerberos scheme. Security issues.