syntax = "proto3";
package celestia.da;

option go_package = "github.com/celestiaorg/celestia-app/proto/celestia/da";

// DataAvailabilityHeader contains the row and column roots of the erasure
// coded version of the data in Block.Data.
// Therefor the original Block.Data is arranged in a
// k × k matrix, which is then "extended" to a
// 2k × 2k matrix applying multiple times Reed-Solomon encoding.
// For details see Section 5.2: https://arxiv.org/abs/1809.09044
// or the Celestia specification:
// https://github.com/celestiaorg/celestia-specs/blob/master/src/specs/data_structures.md#availabledataheader
// Note that currently we list row and column roots in separate fields
// (different from the spec).
message DataAvailabilityHeader {
  // RowRoot_j 	= root((M_{j,1} || M_{j,2} || ... || M_{j,2k} ))
  repeated bytes row_roots = 1;
  // ColumnRoot_j = root((M_{1,j} || M_{2,j} || ... || M_{2k,j} ))
  repeated bytes column_roots = 2;
}