From 4b17aed56712989e8edc5419e2e3e35f10d2d005 Mon Sep 17 00:00:00 2001
From: Emanuel Pargov <bamzedev@gmail.com>
Date: Wed, 31 Jul 2024 14:04:52 +0300
Subject: [PATCH] Add assurance structs (#26)

---
 internal/block/assurance.go | 20 ++++++++++++++++++++
 internal/block/block.go     |  1 +
 2 files changed, 21 insertions(+)
 create mode 100644 internal/block/assurance.go

diff --git a/internal/block/assurance.go b/internal/block/assurance.go
new file mode 100644
index 0000000..e61d0f9
--- /dev/null
+++ b/internal/block/assurance.go
@@ -0,0 +1,20 @@
+package block
+
+import "github.com/eigerco/strawberry/internal/crypto"
+
+// Assurance represents a single validator's attestation of data availability
+// for work reports on specific cores. It is part of the Assurances Extrinsic (E_A).
+// Each Assurance contains:
+// - An anchor to the parent block
+// - A bitstring flag indicating availability for each core
+// - The index of the attesting validator (0 to 1023)
+// - A signature validating the assurance
+// Assurances must be ordered by validator index in the extrinsic.
+type Assurance struct {
+	Anchor         crypto.Hash                       // Parent block hash (a ∈ H)
+	Flag           bool                              // Bitstring of assurances, one bit per core (f ∈ B_C)
+	ValidatorIndex uint16                            // Index of the attesting validator (v ∈ N_V)
+	Signature      [crypto.Ed25519SignatureSize]byte // Ed25519 signature (s ∈ E)
+}
+
+type AssurancesExtrinsic []Assurance
diff --git a/internal/block/block.go b/internal/block/block.go
index df83577..2ccf300 100644
--- a/internal/block/block.go
+++ b/internal/block/block.go
@@ -11,4 +11,5 @@ type Extrinsic struct {
 	ET []*TicketProof
 	EP *PreimageExtrinsic
 	ED *DisputeExtrinsic
+	EA *AssurancesExtrinsic
 }