Ethereum Light Client Helios: A New Trustless Blockchain Access Solution

Recently, a light client for Ethereum called Helios has been launched. This client is developed based on the Rust language and aims to provide completely trustless access to Ethereum.

One major advantage of blockchain technology is that it does not require trust in a third party. Through the blockchain, users can truly control their assets and data. However, for convenience, we often make some compromises. One of these is using centralized RPC( remote calls to ) servers.

Currently, users typically access Ethereum through centralized providers. These companies run high-performance nodes on cloud servers, making it easy for everyone to obtain on-chain data. When wallets query token balances or check transaction statuses, these centralized services are almost always used.

The problem with this approach is that users need to trust these providers, and cannot verify the accuracy of the query results. Helios was created to solve this problem. It can convert data from untrusted centralized RPC providers into securely verifiable local RPC. Combined with centralized RPC, Helios can verify the authenticity of data without running a full node.

One of the major advantages of Helios is that it can complete synchronization in about 2 seconds without the need for storage. Users can securely access on-chain data through any device ( including mobile phones and browser plugins ). This is expected to allow more people to use Ethereum without trust and without being limited by hardware.

Relying on centralized infrastructure may pose potential risks. For example, if the RPC provider does not provide accurate quotes from decentralized exchange smart contracts, users may be misled into signing unfavorable exchange transactions. Worse still, malicious providers may also withhold transactions privately and profit from them.

To avoid these risks, experienced users typically choose to run their own Ethereum nodes. However, this requires a significant amount of time and resources, making it still difficult for most users, especially mobile device users.

Helios consists of an execution layer and a consensus layer. The consensus layer utilizes the synchronization committee of the beacon chain to track the head of the chain by validating the signatures of the synchronization committee. The execution layer combines the validated beacon block headers with the untrusted execution layer RPC to provide validated execution layer data.

This design allows Helios to verify all data from untrusted RPCs without running a full node. While untrusted RPCs can refuse to provide data access, they cannot provide incorrect results.

The application prospects of Helios are promising. Users can use it as an RPC provider in MetaMask, achieving trustless access to various DApps. Developers can also embed Helios into JavaScript applications to enhance the security of Ethereum and reduce reliance on centralized infrastructure.

In the future, Helios has several potential development directions, such as supporting the direct acquisition of light client data from the P2P network, building a WebAssembly version, and integrating into wallet software. These advancements are expected to further enhance the security and decentralization of the Ethereum ecosystem.