Proof of Bank Account

[fvictorio]

Title

  Title: Proof of Bank Account
  Layer: DApps

Abstract

Create a Dapp that allows validators to prove ownership of some bank account.

Rationale

See Igor's post.

Implementation

The PoBA dapp will consist of a frontend that uses the Plaid plugin, a server, a
PoBA smart contract and an ERC780 (claims registry) smart contract.

The data flow will be like this:

• A user goes to the dapp and clicks a button to link their bank account.
• The Plaid plugin shows a modal where the user can log in to their bank.
• This generates a token that the server can use to access the user's bank
  accounts. Since there can be more than one, we'll use the first one for now
  (something to improve in a later iteration).
• The server signs a combination of the wallet address and the bank account
  identifier (and maybe some extra data) and generates some transaction data
  that sends back to the client.
• The user gets the Metamask popup to approve the transaction. Since the
  transaction data is signed, the PoBA smart contract can know that the server
  originated that information.
• The PoBA smart contract associates the bank account information to that wallet
  address and saves the claim to the ERC780 registry. We should define the
  content of the key and value of the claim. We can start with using the hash of
  the data as a key (like we do in PoPA) and just any non-zero value as the
  value.

Note that, unlike PoPA, here the registration and confirmation are done in the
same step (since we don't need to wait for a postcard to arrive to the user's
home).

As mentioned, once this prototype is working, the next step is to allow the user
to choose which bank account to link to their address.

[6proof]

Very good. This method efficiently uses existing systems. Are individual banks / financials required to be members in the Plaid network to participate? Great concept.

[fvictorio]

Are individual banks / financials required to be members in the Plaid network to participate?

I think so, yes. If we rely on their service to validate accounts, then the bank will need to be supported by Plaid.