The collector

The collector in HyveDA is responsible for aggregating attestations made by the DA Nodes and converting them into DAC Certificates. Currently, the collector is a trusted entity, although DAC Certificates can be fully cryptographically verified. Over time, the collector will become decentralized and permissionless. This document details the process of turning attestations into DAC Certificates.

Overview

The collector is connected to the DA Nodes' P2P network and receives attestations via QUIC. It verifies the validity of these attestations and then aggregates them. The aggregation process involves grouping attestations based on their respective blob identifiers. Once enough attestations have been received to satisfy the quorum threshold, a blob certificate is created, containing the aggregate of all attestations. As mentioned earlier in this documentation, the aggregation of signatures uses the BLS12-381 scheme. Each slot, the collector sends a transaction to the DA Registry smart contract with the DAC Certificate. This certificate can then be used by third parties to confirm the data availability of a blob and to enable slashing.

Epochs and slots

The collector is the only component in HyveDA that operates with slots. Each slot lasts 10 seconds, slightly shorter than the Ethereum block time for convenience. During each slot, a transaction is made to the Ethereum smart contract with the DAC Certificate. The DAC Certificate will exist on Ethereum's execution layer indefinitely, as it contains critical information about data availability.

Blob finalization

Each blob must have enough attestations to guarantee data availability. The minimum number of attestations required is determined by the blob's security parameters. For example, a blob in a DAC might need 80% of its attestations to be provided to be deemed available, while another might require 100% of attestations. To expedite blob finalization, the collector notifies DA Nodes over the P2P network which blobs are in the channel. DA Nodes are incentivized to provide attestations for these blobs, as their inclusion is almost guaranteed, resulting in rewards for the attestors.

Low latency certificates

The collector will be connected to a P2P network where clients can subscribe to DAC Certificate updates. These updates are accompanied by cryptographic proofs of a blob's inclusion. Consequently, clients can be certain their blob will be included in the next DAC Certificate before it is sent to the chain. This enables lower latencies for data availability certificates, eliminating bottlenecks for DA implementers.