> For the complete documentation index, see [llms.txt](https://docs.roguechain.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.roguechain.io/rogue-protocol/rogue-chain/anytrust-revolutionizing-blockchain-infrastructure/data-availability-certificates-dacerts.md).

# Data Availability Certificates (DACerts)

At the core of AnyTrust lies the concept of the Data Availability Certificate (DACert). This certificate comprises the hash of a data block, an expiration time, and evidence that N-1 Committee members have signed the (hash, expiration time) pair. This evidence includes the hash of the Keyset used for signing, a bitmap indicating the signing Committee members, and a BLS aggregated signature over the BLS12-381 curve, affirming the authenticity of the signatures.

Operating on the 2-of-N trust assumption, a DACert provides assurance that a block's data will be accessible from at least one honest Committee member until the specified expiration time. This foundational trust assumption forms the basis for the reliability and security of data availability within the AnyTrust framework.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## 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, and the optional `goal` query parameter:

```
GET https://docs.roguechain.io/rogue-protocol/rogue-chain/anytrust-revolutionizing-blockchain-infrastructure/data-availability-certificates-dacerts.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.