Common Whitepaper - Differences

Common Whitepaper

The Common Whitepaper: https://eprint.iacr.org/2023/1868 is a paper describing an Order Book DEX with privacy features, a joint work between Cardinal Cryptography and Nethermind researchers.

The Common DEX that we implement as part of Common -- the Privacy Suite on Aleph Zero -- is heavily inspired by the Common Whitepaper, however there are also several differences between the two. These differences aim at:

• making the DEX also usable and efficient (in terms of prices offered to users) in the non-private mode,

• making the design more modular, thus allowing shipment of the product in stages,

• simplifying the order flow and interactions with the Decryption Oracle.

Similarities with Common DEX

The foundation of the Common protocol in the whitepaper is a shielded pool. This is also true for Common DEX -- by default, each user action in Common DEX is anonymous -- it originates and concludes in the shielded pool. The concrete implementation of the underlying shielded pool (referred to as "anonymity pool" in the whitepaper) is the Shielder from this documentation.

As in the Common Whitepaper, Common DEX separates the interactions with the anonymity pool and the execution engine of the DEX (referred to as "Swap Engine" in the whitepaper). In fact, in the DEX the execution engine is even further separated and the users are able to interact with it directly.

Differences with Common DEX

In the Common Whitepaper the only mode to use the Order book is via submitting private orders (or by filling orders), in Common DEX this changes -- privacy is opt-in, and it will be possible to submit orders publicly.

In the whitepaper the Dutch auctions are run as part of the swap phase. In the Common DEX implementation, the Dutch auction mechanism is generalized and used to match regular, plaintext orders using a mechanism akin to Uniswap-X or CowSwap.

The Decryption Oracle in the whitepaper is used to decrypt the batched orders from subsequent rounds. Common DEX on the other hand will allow more sophisticated use patterns of the Decryption Oracle -- for instance Iceberg Orders.