Introduction to Configurable Asset Privacy for Ethereum (CAPE)
This documentation site is dedicated to CAPE: Configurable Asset Privacy for Ethereum.
CAPE is a smart contract application developed by Espresso Systems that enables digital asset creators to configure who can see data regarding the custody and transfer of the assets they create. Users can create new tokens and wrap existing Ethereum tokens to give them the desired privacy properties.
Using CAPE, a digital asset creator can define viewing policies for their assets concerning any of the following data:
  • Sender and receiver addresses
  • The amount of an asset sent, received, and held
  • The type of asset being sent, received, and held
In addition to viewing policies, asset creators can also use CAPE to define other policies around their assets, including freezing policies, offering asset creators like stablecoin providers the ability to retain controls to address fraud, theft, and dispute resolution.
For end users, CAPE offers better privacy options for sending, receiving, and holding assets than what is offered natively on Ethereum today. An important consideration in designing CAPE has been to allow users to have a clear understanding of who has insights into and controls over their transactions, and to empower users to actively opt in and out of the data they are sharing. For this reason, configured policies for CAPE assets are shown in the user interface that we have designed.
CAPE is also designed to support credential issuers and users. Espresso Systems is glad to be collaborating closely with industry leaders like CENTRE in designing decentralized identity standards.
CAPE is open-sourced here. While CAPE can be run on any EVM blockchain, we have deployed it as a demo on the Arbitrum Goerli testnet, with plans to deploy CAPE to more testnets and mainnets soon. Stay tuned on our Twitter and Discord!
To learn more about the technology behind CAPE, see the CAPE Technical Documentation section. Or, to get started with CAPE immediately, jump into the CAPE User Guide.