diff --git a/scls-cardano/cddl-src/Cardano/SCLS/CDDL.hs b/scls-cardano/cddl-src/Cardano/SCLS/CDDL.hs
index 2047a8e0..57d474c7 100644
--- a/scls-cardano/cddl-src/Cardano/SCLS/CDDL.hs
+++ b/scls-cardano/cddl-src/Cardano/SCLS/CDDL.hs
@@ -15,6 +15,7 @@ import Cardano.SCLS.Namespace.GovCommittee qualified as GovCommittee
 import Cardano.SCLS.Namespace.GovConstitution qualified as GovConstitution
 import Cardano.SCLS.Namespace.GovPParams qualified as GovPParams
 import Cardano.SCLS.Namespace.GovProposals qualified as GovProposals
+import Cardano.SCLS.Namespace.Nonces qualified as Nonces
 import Cardano.SCLS.Namespace.PoolStake qualified as PoolStake
 import Cardano.SCLS.Namespace.Pots qualified as Pots
 import Cardano.SCLS.Namespace.Snapshots qualified as Snapshots
@@ -46,6 +47,7 @@ namespaces =
     , mkDefinition @"pots/v0" Pots.record_entry
     , mkDefinition @"pool_stake/v0" PoolStake.record_entry
     , mkDefinition @"snapshots/v0" Snapshots.record_entry
+    , mkDefinition @"nonces/v0" Nonces.record_entry
     , mkDefinition @"gov/committee/v0" GovCommittee.record_entry
     , mkDefinition @"gov/constitution/v0" GovConstitution.record_entry
     , mkDefinition @"gov/pparams/v0" GovPParams.record_entry
@@ -64,6 +66,7 @@ mkDefinition r =
 
 type instance Spec.NamespaceKeySize "utxo/v0" = 34
 type instance Spec.NamespaceKeySize "blocks/v0" = 36 -- 28 bytes for key, and 8 for epoch in BE
+type instance Spec.NamespaceKeySize "nonces/v0" = 1 -- Just zero
 type instance Spec.NamespaceKeySize "pots/v0" = 8 -- Key is epoch number
 type instance Spec.NamespaceKeySize "pool_stake/v0" = 28 -- 28 bytes for key
 type instance Spec.NamespaceKeySize "snapshots/v0" = 32 -- 1 byte for hash type, 1 byte for stage, 29 bytes for hash (cred 29, key 28+1),  1 for value type
diff --git a/scls-cardano/cddl-src/Cardano/SCLS/Common.hs b/scls-cardano/cddl-src/Cardano/SCLS/Common.hs
index e2dcfb6c..ae49ee89 100644
--- a/scls-cardano/cddl-src/Cardano/SCLS/Common.hs
+++ b/scls-cardano/cddl-src/Cardano/SCLS/Common.hs
@@ -68,10 +68,10 @@ address = "address" =:= VBytes
 --------------------------------------------------------------------------------
 
 keyhash32 :: Rule
-keyhash32 = "keyhash28" =:= hash32
+keyhash32 = "keyhash32" =:= hash32
 
 keyhash28 :: Rule
-keyhash28 = "keyhash32" =:= hash28 -- Important: seems on the current chain it's 32
+keyhash28 = "keyhash28" =:= hash28 -- Important: seems on the current chain it's 32
 
 hash28 :: Rule
 hash28 = "hash28" =:= VBytes `sized` (28 :: Word64)
@@ -119,6 +119,9 @@ big_nint = "big_nint" =:= tag 3 bounded_bytes
 int64 :: Rule
 int64 = "int64" =:= toInteger (minBound @Int64) ... toInteger (maxBound @Int64)
 
+word64 :: Rule
+word64 = "word64" =:= VUInt `sized` (8 :: Word)
+
 -------------------------------------------------------------------------------
 -- Utility
 --------------------------------------------------------------------------------
diff --git a/scls-cardano/cddl-src/Cardano/SCLS/Namespace/Nonces.hs b/scls-cardano/cddl-src/Cardano/SCLS/Namespace/Nonces.hs
new file mode 100644
index 00000000..0b782250
--- /dev/null
+++ b/scls-cardano/cddl-src/Cardano/SCLS/Namespace/Nonces.hs
@@ -0,0 +1,68 @@
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE OverloadedLists #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
+
+{-# HLINT ignore "Use camelCase" #-}
+module Cardano.SCLS.Namespace.Nonces where
+
+import Cardano.SCLS.Common
+import Codec.CBOR.Cuddle.Huddle
+import Text.Heredoc (str)
+import Prelude (($))
+
+record_entry :: Rule
+record_entry =
+  comment
+    [str| Key is just zero
+        |
+        | ```
+        | meta:
+        |   endian: be
+        |
+        | seq:
+        |   - id: key
+        |     type: nonce
+        |
+        | types:
+        |   nonce:
+        |     doc: Nonce value
+        |     size: 1
+        |     type: u1
+        |     const: 0
+        | ```
+        |
+        |]
+    $ "record_entry" =:= nonces
+
+nonces :: Rule
+nonces =
+  comment
+    [str| List of nonces used in the protocol state
+        |
+        |]
+    $ "nonces"
+      =:= mp
+        [ "last_slot" ==> with_origin slot_no
+        , "cert_counters" ==> mp [0 <+ asKey keyhash32 ==> word64]
+        , "evolving_nonce" ==> nonce
+        , "candidate_nonce" ==> nonce
+        , "epoch_nonce" ==> nonce
+        , "lab_nonce" ==> nonce
+        , "last_epoch_block_nonce" ==> nonce
+        ]
+
+nonce :: Rule
+nonce = "nonce" =:= neutral_nonce / just_nonce
+
+neutral_nonce :: Rule
+neutral_nonce = "neutral_nonce" =:= arr [0]
+
+just_nonce :: Rule
+just_nonce = "just_nonce" =:= arr [1, a hash32]
+
+with_origin :: (IsType0 t0) => t0 -> GRuleCall
+with_origin = binding $ \x -> "with_origin" =:= arr [0] / arr [1, a x]
diff --git a/scls-cardano/scls-cardano.cabal b/scls-cardano/scls-cardano.cabal
index b92256f0..93788d75 100644
--- a/scls-cardano/scls-cardano.cabal
+++ b/scls-cardano/scls-cardano.cabal
@@ -33,6 +33,7 @@ library
     Cardano.SCLS.Namespace.GovConstitution
     Cardano.SCLS.Namespace.GovPParams
     Cardano.SCLS.Namespace.GovProposals
+    Cardano.SCLS.Namespace.Nonces
     Cardano.SCLS.Namespace.PoolStake
     Cardano.SCLS.Namespace.Pots
     Cardano.SCLS.Namespace.Snapshots