Title:

Technical RFC: ZEC-NAM shielded airdrop mechanism

Body:

Hello Zcashers,

The Heliax team (developing Anoma & Namada) would like to reach out to you again for an update on the shielded airdrop, previously discussed [here](https://forum.zcashcommunity.com/t/on-namada-zcash-alliance-shielded-airdrop-to-zcash-holders/46189). In the time since that post, we have come up with a more detailed protocol design and a small demo to proof-of-concept the most important aspect of the airdrop transaction, and we would like to show it to you and collect feedback.

Both the protocol details and the demo can be found in [this GitHub repo](https://github.com/anoma/namada-shielded-airdrop).

We would be enthusiastic about any technical feedback you wish to discuss with us concerning protocol correctness, privacy-preservation, and ease of integration into wallets etc. If you wish to discuss the airdrop _program_ please reply to the former post - let's keep this thread to technical details and discussions only.

Best wishes,
Carlo