Author:Haotian
Recently, there has been a lot of discussion about the differences between ZK and Trusted Execution Environment (TEE). The reason is that @unichain, a newcomer to layer2, claims that its millisecond-level sub-blocks are built on TEE, while @FlareNetworks, an old oracle chain that claims to be a data blockchain, integrates traditional Internet channels such as Google Cloud and introduces verifiable off-chain computing through TEE. Combining these two things, let me talk about my views:
1) TEE (Trusted Execution Environment) is a hardware-level security technology. Simply put, TEE creates an independent, secure, and isolated Enclave environment in the processor, which is completely isolated from the main operating system program. It can safely store and protect sensitive data and has a strict access control mechanism.
This means that developers can execute specific programs in TEE, fully amplifying the execution efficiency and performance of the hardware while ensuring security. Currently, there are many different TEE implementations, including Intel SGX ARM TrustZone, which have wider applications in the fields of mobile Internet, Internet of Things, etc., and applications in blockchain scenarios are being explored.
2) Unichain is based on the TEE environment, which allows transactions to be pre-executed and verified before they are officially packaged into blocks. This breaks the limitation that transactions must be uploaded to Mempool and wait for packaging, and provides a relatively safe and closed anti-tampering environment, so it can be realized.
Flare Network's idea of being an oracle is also magnified with the help of the TEE environment. It would be very cumbersome to use the oracle data blockchain to feed prices (Price indicators) for the DeFi contract environment. If the data range is expanded to include sports game results, social media data, real-time election rankings, etc., it requires huge off-chain computing and processing capabilities, and finally delivers the verifiable results to the on-chain environment.
Flare will use the TEE environment provided by Google Cloud to perform intensive computing operations and only feed trusted results to the chain, avoiding the accumulation of large data sources on the chain and generating large costs. The idea is simple: complex computing tasks are performed off-chain and then verified on-chain through short proofs, which can reduce the data load and computing requirements on the chain.
3) By analogy, it is not difficult to find that the TEE trusted execution environment relies on hardware manufacturers (such as AMD, Intel) to some extent, combined with traditional upstream service providers such as Google Cloud to provide "trustworthiness", pre-processing the original data, and finally applying the data results to the chain. This is a key difference from ZK's trust based on mathematical principles and cryptographic algorithms that does not rely on any hardware: TEE requires a third-party trust party.
How to solve this problem? The logic is simple: TEE + verifiable Prove network. Introducing a verifiable proof network can significantly improve the transparency and credibility of the TEE system. The decentralized verification network that Unichain is going to introduce and the distributed node governance architecture provided by Flare's own blockchain architecture both play the role of this verification network.
Although Unichain has not yet disclosed the implementation and governance details of this verification network, how to utilize the remote authentication features of the TEE enclave environment and how to generate proofs and interact with the on-chain environment under the premise of hardware security and confidentiality must be the key points.
