Quick Background
For those that don't know, Chaumian eCash was created by David Chaum in the 80s - the implementation was known as DigiCash and it even saw use at a US bank from 1995 - 1998.
It introduces near perfect privacy (blinded amounts + transmission).
Bitcoin
eCash is being used as an add-on to bitcoin (not in competition), specifically there are a couple of implementations happening now on LN (ie. cashu, nutstash.app, etc) and on-chain (Fedimints, etc).
Features
- Blinded Amounts
- Can be used both on-chain and on LN
- NOT UTXO based - but Bearer based (no online requirement, transport agnostic)
- eCash is "minted" and transactions between users of same mint are instant and no-fee
- eCash can transfer between mints via LN (or other ways)
- Can hold other "assets" (ie. USDT, tokens, etc)
- Scales bitcoin
But how exactly does this "scale" bitcoin?
Its a nuanced discussion, but most of us now understand that scaling BTC to entire world on-chain will never happen (mathematically impossible - not to mention fee issues). Therefore we need some form of "Custodians" to get 6B people both on the network and transacting. Even though LN by itself helps tremendously, there is no way to open that many channels on-chain, so custodians of some sort will be needed....the problem custodians bring is that they can/will be pressured by state actors to censor transactions. Custodians can and will be tempted to spy on users and use captured data for their advantage at expense of user.
eCash solves this since it becomes (a) impossible for Custodian to know what is being transferred AND (b) because its bearer-based, its impossible for Custodian to know even know assets are trading hands (ie. you could literally download "ecash.json" file and send via WhatsApp and its like sending physical cash over chat network).
How can I get started
Quickest way right now, is to spin up an instance of LN wallet at https://legend.lnbits.com and enable the "Cashu" extension. Then you can create a mint, issue some assets and play around.
You can use the https://wallet.nutstash.app/ web wallet to transfer assets to your lnbits wallet and see how it works. There are also wallets available for iOS / Android (https://enuts.cash)