Testament

Testament turns every iPhone into a TEE that crypto apps can use to run secure computation using the same trust assumptions as a cloud-based TEE service. This make TEEs more decentralized by lowering the barrier to entry using one from "only nerds who can spin up a beefy cloud server" to "everyone with a phone in their pocket". It also allows crypto apps to compute over private data locally without data ever leaving a user's device. These two properties open up many new use cases for crypto developers to build - from distributed data oracles to fully-verifiable onchain games.

Testament utilizes mobile hardware attestations signed by Apple's root certificate, giving every computation the full security of Apple's hardware supply chain and an Apple-certified guarantee that the computation was performed correctly without tampering.

The Testament mobile app is build using React Native and calls into Apple's AppAttest native framework to generate hardware attestations and signatures proving correct computation. Testament exposes a deeplink-based API that apps can use to execute computations inside the TEE, and communicates the computation results back to the app using a callback URL. An example app shows the full data flow from web -> mobile -> back to web, and implements full offchain verification of the TEE attestations and signatures.