Add ticket structs

internal/block/block.go

@@ -1,4 +1,12 @@
 package block
 
+// Block represents the main block structure
 type Block struct {
+	Header    *Header
+	Extrinsic *Extrinsic
+}
+
+// Extrinsic represents the block extrinsic data
+type Extrinsic struct {
+	ET []*TicketProof
 }

internal/block/ticket.go

@@ -0,0 +1,20 @@
+package block
+
+import "github.com/eigerco/strawberry/internal/crypto"
+
+const (
+	maxTicketsPerBlock = 16  // `K` in the paper. The maximum number of tickets which may be submitted in a single extrinsic.
+	ticketProofSize    = 784 // Size of F̄[]γz⟨XT ⌢ η′2 r⟩
+)
+
+// Ticket represents a single ticket (C in equation 50)
+type Ticket struct {
+	Identifier crypto.Hash // y ∈ H 32bytes hash
+	EntryIndex uint8       // r ∈ Nn (0, 1)
+}
+
+// TicketProof represents a proof of a valid ticket
+type TicketProof struct {
+	EntryIndex uint8                 // r ∈ Nn (0, 1)
+	Proof      [ticketProofSize]byte // RingVRF proof
+}