At a high-level Porter probably needs to support Alice.grant and Alice.revoke interactions. Determine what underlying functionality needs to be provided to facilitate this workflow.

For Alice specifically:

• Sampling of ursulas for a policy as part of Alice.grant - return ursula and associated public keys
• KFrag distribution as part of sharing policy - this would be rendered obsolete by TreasureMap con KFrags (?) -
• TreasureMap publication (can be side channelled) - Porter can do distribution if desired - how is this affected by TreasureMap con KFrags (?)
• Revocation - Off-chain revocation would be Alice giving Porter a revocation kit for Porter to contact Ursulas to delete Kfrags (TreasureMap sin Kfrags), or add the KFrags to a reject list (TreasureMap con KFrags)
  ...others...?

Delivery here could be in the form of a comprehensive list of areas to be tackled, and a list of potential functions (and required inputs and outputs) that could be exposed by Porter. Extra credit for sequence diagrams 😅 j/k .