Founded in 2017 and jointly funded by A16Z and Paradigm, the ancient privacy blockchain Aztec is about to launch its TGE. Unlike Zama, which grafts privacy layers onto other chains through FHE, Aztec's privacy capabilities are more native and employ a hybrid privacy model. It allows users to specify which data is public and which is private. The privacy data status uses a model similar to Bitcoin's UTXO, as UTXOs are inherently more suitable for privacy than the account model. With an account model, for example, if you hold 100USD and transfer 30USD, leaving 70USD, everyone on the chain can immediately see who you transferred it to based on wallet asset changes. Therefore, any operation that directly modifies the corresponding wallet data is the antithesis of privacy. Therefore, in Aztec, each asset is called a "note," which stores data such as funds and holder information. Each transfer does not directly modify the note; instead, the old note is destroyed, and one or more new notes are created. The nullifier is an encrypted fingerprint generated for each note, used to identify whether the corresponding note has been used and destroyed. As a nearly 10-year-old project, Aztec's privacy technology has been used by zkSync, Polygon, and others. JPMorgan Chase included it in its financial privacy assessment in 2019.