WIP - Hierarchical Deterministic Note

[yoyoismee]

This is a WIP PR.

just wanna get some feedback before I spend more time on it.

motivation

to move a large sum through Torn would require multiple notes which might become messy.
(never experience that problem myself tho since I'm not that rich)

proposed ideas

the idea is to use a BIP39 style HD wallet to deterministically create multiple notes.
together with another function to deterministically create a deposit sequence.
we can use 1 note to control any amount of funds.

implementation

genCompactNote(currency, amount, netId)

create a note that contains currency, amount, netId and newly generated mnemonic.
note that unlike normal notes amount can be any number. e.g. 420 ETH is ok

createMultipleDeposit(mnemonic, amount )

deterministically generate deposits (the object with commitment, and others info) start from idx 0.
create deposit by using idx2 as secret and idx2 +1 as nullifier

recoverDepositFromMnemonic(mnemonic, idx)

create deposit based on mnemonic, idx.

taskSplit (amount, options )

greedy based task splitting.
e.g. 420.69 via ETH torn -> 4 * 100 + 2 * 10 + 6* 0.1

next step

if Torn commu/dev think we should go ahead with this feature.
the next step would be to complete the feature by implement

• note parser
• deposit flow
  • take in currency amount netID
  • create an HD note with that info
  • split tasks
  • generate enough deposits
  • loop through the tasks and make a deposit with the corresponding commitment
• not sure if we should have a withdrawal flow. since the mass withdrawal is a bad idea.
• command line

[yoyoismee]

sample result

[ghost]

@yoyoismee This is somewhat great feature for Tornado.Cash and it is actually better approach to manage multiple deposits than the on-chain backup feature as well!

Will be including this PR as well after some refactoring of cli.