# Introducing zkBridge protocol

zkBridge uses zkSNARKs to enable a prover to efficiently convince the receiver chain that a certain state transition happened on the sender chain. zkBridge consists of a block header relay network and an updater contract.

The block header relay network retrieves the block headers from the sender chain, generates proofs of the validity of the block headers, and sends the headers along with the proofs to the updater contract (set up on the receiver chain).

The updater contract maintains a light-client state. It automatically adds block headers of the sender chain once the associated proofs are verified, and updates the current main chain of the sender chain.

<figure><img src="https://1490802357-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fnh72Z9AlRZpyxWkeGHh5%2Fuploads%2FxtANhMXIwjp18zUiutP1%2Fimage.png?alt=media&#x26;token=40bed31f-a18d-4b9e-a8c0-7caa3dd3eff6" alt=""><figcaption></figcaption></figure>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.zkbridge.com/zkbridge-trustless-cross-chain-bridges-made-practical/introducing-zkbridge-protocol.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.