diff --git a/src/Challenge/FRI.hs b/src/Challenge/FRI.hs
index 2a3371c..08f2ae0 100644
--- a/src/Challenge/FRI.hs
+++ b/src/Challenge/FRI.hs
@@ -12,13 +12,13 @@ import Data.Bits
 
 import Algebra.Goldilocks
 import Algebra.GoldilocksExt
-import Hash
-import Digest
+import Hash.Sponge
+import Hash.Digest
 import Types
 import Challenge.Monad
 
-import Debug.Trace
-debug x y z = trace ("\n - " ++ x ++ " -> " ++ show y) z
+-- import Debug.Trace
+-- debug x y z = trace ("\n - " ++ x ++ " -> " ++ show y) z
 
 --------------------------------------------------------------------------------
 
diff --git a/src/Challenge/Monad.hs b/src/Challenge/Monad.hs
index dad332f..9376fb0 100644
--- a/src/Challenge/Monad.hs
+++ b/src/Challenge/Monad.hs
@@ -14,7 +14,7 @@ import qualified Control.Monad.State.Strict as S
 import Control.Monad.IO.Class
 
 import Algebra.Goldilocks
-import Digest
+import Hash.Digest
 import Challenge.Pure ( DuplexState, Squeeze, Absorb )
 import qualified Challenge.Pure as Pure
 
diff --git a/src/Challenge/Pure.hs b/src/Challenge/Pure.hs
index 5a32704..cccb405 100644
--- a/src/Challenge/Pure.hs
+++ b/src/Challenge/Pure.hs
@@ -17,8 +17,8 @@ import Data.Array
 
 import Algebra.Goldilocks
 import Algebra.GoldilocksExt
-import Poseidon
-import Digest
+import Hash.Poseidon
+import Hash.Digest
 import Types
 
 --------------------------------------------------------------------------------
diff --git a/src/Challenge/Verifier.hs b/src/Challenge/Verifier.hs
index 50c8148..78dab08 100644
--- a/src/Challenge/Verifier.hs
+++ b/src/Challenge/Verifier.hs
@@ -8,8 +8,8 @@ module Challenge.Verifier where
 
 import Algebra.Goldilocks
 import Algebra.GoldilocksExt
-import Hash
-import Digest
+import Hash.Sponge
+import Hash.Digest
 import Types
 
 import Challenge.Monad
diff --git a/src/Constants.hs b/src/Hash/Constants.hs
similarity index 99%
rename from src/Constants.hs
rename to src/Hash/Constants.hs
index 6527344..5eab5ec 100644
--- a/src/Constants.hs
+++ b/src/Hash/Constants.hs
@@ -3,7 +3,7 @@
 --
 -- See <https://github.com/0xPolygonZero/plonky2/blob/main/plonky2/src/hash/poseidon_goldilocks.rs>
 
-module Constants where
+module Hash.Constants where
 
 --------------------------------------------------------------------------------
 
diff --git a/src/Digest.hs b/src/Hash/Digest.hs
similarity index 98%
rename from src/Digest.hs
rename to src/Hash/Digest.hs
index 1ea4a0f..578d784 100644
--- a/src/Digest.hs
+++ b/src/Hash/Digest.hs
@@ -1,6 +1,6 @@
 
 {-# LANGUAGE DeriveGeneric, OverloadedStrings #-}
-module Digest where
+module Hash.Digest where
 
 --------------------------------------------------------------------------------
 
diff --git a/src/Poseidon.hs b/src/Hash/Poseidon.hs
similarity index 97%
rename from src/Poseidon.hs
rename to src/Hash/Poseidon.hs
index c87b2fe..fef1d32 100644
--- a/src/Poseidon.hs
+++ b/src/Hash/Poseidon.hs
@@ -5,7 +5,7 @@
 --
 
 {-# LANGUAGE Strict #-}
-module Poseidon where
+module Hash.Poseidon where
 
 --------------------------------------------------------------------------------
 
@@ -15,8 +15,8 @@ import Data.Array (Array)
 import Data.Array.IArray
 
 import Algebra.Goldilocks
-import Constants
-import Digest
+import Hash.Constants
+import Hash.Digest
 
 --------------------------------------------------------------------------------
 
diff --git a/src/Hash.hs b/src/Hash/Sponge.hs
similarity index 95%
rename from src/Hash.hs
rename to src/Hash/Sponge.hs
index 2bc040d..80caf4d 100644
--- a/src/Hash.hs
+++ b/src/Hash/Sponge.hs
@@ -1,5 +1,5 @@
 
-module Hash where
+module Hash.Sponge where
 
 --------------------------------------------------------------------------------
 
@@ -8,8 +8,8 @@ import Data.Word
 import Data.Bits
 
 import Algebra.Goldilocks
-import Poseidon
-import Digest
+import Hash.Poseidon
+import Hash.Digest
 
 --------------------------------------------------------------------------------
 
diff --git a/src/Types.hs b/src/Types.hs
index d19c706..405dba4 100644
--- a/src/Types.hs
+++ b/src/Types.hs
@@ -17,7 +17,7 @@ import GHC.Generics
 
 import Algebra.Goldilocks
 import Algebra.GoldilocksExt
-import Digest
+import Hash.Digest
 import Gate.Base
 import Gate.Parser
 
diff --git a/src/testmain.hs b/src/testmain.hs
index dacdd50..f4e07d2 100644
--- a/src/testmain.hs
+++ b/src/testmain.hs
@@ -6,8 +6,8 @@ module Main where
 import Data.Aeson
 
 import Types
-import Hash
-import Digest
+import Hash.Sponge
+import Hash.Digest
 import Algebra.Goldilocks
 import Challenge.Verifier