Shielded Actions education & messaging

[proper crest]

i think we'll need to do some solid messaging and education around Shielded Actions, if anyone wants to collaborate

[proper crest]

@flat arrow how do Shielded Actions work? at the most basic level

this is likely outside of your domain of expertise, but you probably know how to get a god synopsis of this

[next flare]

Hi, which type of zk-SNARK will Namada use, Sapling or Halo2?

[proper crest]

hi! iirc, modified Sapling cct

[flat arrow]

Hi! Sry just seeing this. The MASP in Namada does indeed use an extended Sapling circuit. Here's the MASP repo if you want to peek around the cryptography: https://github.com/anoma/masp

[versed snow]

Do you mean explaining concepts and processes like shielding, unshielding and paying fees while preventing information leakage to end-users? I prefer letting the UX handle that as much as possible through convention over configuration, because letting end-users figure out gas payer, gas spending keys and disposable gas payer, they are bound to make mistakes and expose themselves.

[versed snow]

WARNING: Some information might be leaked if your shielded wallet is not up to date, make sure to run `namadac shielded-sync` before running this command.

Why?

[proper crest]

no, i mean how developers can create and use Shielded Actions
wow i'm late

[quaint tapir]

I can't go into the details because im not smart enough to understand it, but everytime a shielded payment is made, the on-chain masp UTXO is updated. When you shieldsync you basically sync your local UTXO with the on-chain masp UTXO. This means that, even if you didnt' shieldsync, you might have enough information locally to produce a valid masp spending transaction, but you will reveal that you have been able to spend a note with an older "version" of the masp UTXO. You are basically leaking some time information