Firn Protocol is the first ever privacy service which uses the account-based model (like Ethereum)

Firn is a state-of-the-art, zero-knowledge privacy utility for Ethereum and EVM-based rollups. Firn supports not just private payments, but the private invocation of arbitrary smart contracts. Firn moreover allows deposits and withdrawals of arbitrary amounts of Ether, as well as private, peer-to-peer payments (in which the sender's and receiver's identities and the amount being transferred are all hidden). In this light, Firn can be viewed as something like a general-purpose private wallet for EVM-based blockchains.

Unlike all other projects in the privacy space, Firn uses an account-based architecture. In practical terms, this means that Firn's browser-based wallet can retrieve and synchronize your account state extremely efficiently, downloading less than a kilobyte of data in the process. Other projects require data downloads in the megabytes or more, and feature extremely long synchronization times. This latter requirement has proven prohibitive in multiple instances (including Aztec Connect, which had an insurmountable bug load and was deprecated, and Zcash, which faced a crippling "spam attack"). As privacy projects continue to grow and mature, we believe that our wallet's superior efficiency will prove decisive.

The crucial thing to understand is that Firn is account-based; every other live-and-working cryptographic privacy protocol is UTXO-based. This distinction is analogous to that between Ethereum and Bitcoin. Indeed, you can think of Firn as something like "Ethereum, but private"; other protocols—like Zcash, Monero, and Aztec—are more like "Bitcoin, but private."

Firn’s state consists of a global table of accounts. (These are analogous to those constituting Ethereum’s global account table, but they exist within Firn’s contract.) Just as Ethereum associates, to each account, a balance—and also code, storage, etc. in the case of contract.

This is how Firn gets away with running entirely in an extremely lightweight browser client. Firn’s front-end is hosted entirely statically on IPFS, and can even be accessed as a Tor hidden service. Firn has no off-chain rollup (like Aztec does), and Firn proofs can be generated by the browser entirely unassistedly. Firn’s browser client must only download a few hundred bytes (compared to megabytes in the case of Aztec); it’s completely stateless, and stores nothing locally (unlike Aztec); finally, Firn synchronizes instantly, even on fresh devices. Firn’s liveness depends only on the L1’s liveness. During synchronization and proof-generation, Firn communicates only through the selected wallet (whose RPC is controlled by the user), and does not initiate any “backdoor” connections to Firn-specific services. (When you actually dispatch a withdrawal or transfer, a one-time zero-knowledge proof gets sent to the Firn relay, which pays gas and forwards it to the blockchain. This proof reveals nothing to the relay. The relay does not collect any IP information.)

Visit us at app.firn.cash to learn more