diff --git a/mysticeti.nim b/mysticeti.nim
index f5f5711..9072720 100644
--- a/mysticeti.nim
+++ b/mysticeti.nim
@@ -15,10 +15,11 @@ import ./mysticeti/blocks
 
 export blocks.Transaction
 export blocks.Block
+export blocks.BlockId
 export blocks.author
 export blocks.round
 export blocks.parents
-export blocks.blockHash
+export blocks.id
 export blocks.SignedBlock
 export blocks.blck
 export blocks.signer
diff --git a/mysticeti/blocks.nim b/mysticeti/blocks.nim
index d78dd5a..1217f29 100644
--- a/mysticeti/blocks.nim
+++ b/mysticeti/blocks.nim
@@ -7,27 +7,31 @@ type
   Block*[Signing, Hashing] = object
     author: Identifier[Signing]
     round: uint64
-    parents: seq[Hash[Hashing]]
+    parents: seq[BlockId[Signing, Hashing]]
     transactions: seq[Transaction]
+  BlockId*[Signing, Hashing] = object
+    author: Identifier[Signing]
+    round: uint64
+    hash: Hash[Hashing]
 
 func new*(
   _: type Block,
   author: Identifier,
   round: uint64,
-  parents: seq[Hash],
+  parents: seq[BlockId],
   transactions: seq[Transaction]
 ): auto =
-  Block[Identifier.Signing, Hash.Hashing](
+  Block[BlockId.Signing, BlockId.Hashing](
     author: author,
     round: round,
     parents: parents,
     transactions: transactions
   )
 
-func author*(blck: Block): auto =
+func author*(blck: Block | BlockId): auto =
   blck.author
 
-func round*(blck: Block): uint64 =
+func round*(blck: Block | BlockId): uint64 =
   blck.round
 
 func parents*(blck: Block): auto =
@@ -36,8 +40,12 @@ func parents*(blck: Block): auto =
 func toBytes(blck: Block): seq[byte] =
   cast[seq[byte]]($blck) # TODO: proper serialization
 
-func blockHash*(blck: Block): auto =
-  Block.Hashing.hash(blck.toBytes)
+func id*(blck: Block): auto =
+  BlockId[Block.Signing, Block.Hashing](
+    author: blck.author,
+    round: blck.round,
+    hash: Block.Hashing.hash(blck.toBytes)
+  )
 
 type SignedBlock*[Signing, Hashing] = object
   blck: Block[Signing, Hashing]
diff --git a/mysticeti/validator.nim b/mysticeti/validator.nim
index c697030..44229db 100644
--- a/mysticeti/validator.nim
+++ b/mysticeti/validator.nim
@@ -1,6 +1,5 @@
 import ./basics
 import ./signing
-import ./hashing
 import ./blocks
 
 type
@@ -48,10 +47,10 @@ func nextRound*(validator: Validator) =
 
 proc propose*(validator: Validator, transactions: seq[Transaction]): auto =
   assert validator.identifier notin validator.round.slots
-  var parents: seq[Hash[Validator.Hashing]]
+  var parents: seq[BlockId[Validator.Signing, Validator.Hashing]]
   if previous =? validator.round.previous:
     for id in previous.slots.keys:
-      parents.add(previous.slots[id].proposal.blockHash)
+      parents.add(previous.slots[id].proposal.id)
   let blck = Block.new(
     author = validator.identifier,
     round = validator.round.number,
diff --git a/tests/testValidator.nim b/tests/testValidator.nim
index e718d38..cb9e1af 100644
--- a/tests/testValidator.nim
+++ b/tests/testValidator.nim
@@ -64,7 +64,7 @@ suite "Validator":
     validator1.receive(proposal4)
     validator1.nextRound()
     let proposal5 = validator1.propose(seq[Transaction].example)
-    check proposal1.blck.blockHash in proposal5.blck.parents
-    check proposal2.blck.blockHash in proposal5.blck.parents
-    check proposal3.blck.blockHash in proposal5.blck.parents
-    check proposal4.blck.blockHash in proposal5.blck.parents
+    check proposal1.blck.id in proposal5.blck.parents
+    check proposal2.blck.id in proposal5.blck.parents
+    check proposal3.blck.id in proposal5.blck.parents
+    check proposal4.blck.id in proposal5.blck.parents