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diff --git a/src/VeriFuzz/Circuit/Random.hs b/src/VeriFuzz/Circuit/Random.hs
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+{-|
+Module      : VeriFuzz.Circuit.Random
+Description : Random generation for DAG
+Copyright   : (c) 2018-2019, Yann Herklotz Grave
+License     : BSD-3
+Maintainer  : ymherklotz [at] gmail [dot] com
+Stability   : experimental
+Portability : POSIX
+
+Define the random generation for the directed acyclic graph.
+-}
+
+module VeriFuzz.Circuit.Random where
+
+import           Data.Graph.Inductive              (Context, LEdge)
+import qualified Data.Graph.Inductive              as G
+import           Data.Graph.Inductive.PatriciaTree (Gr)
+import           Data.List                         (nub)
+import           Test.QuickCheck                   (Arbitrary, Gen)
+import qualified Test.QuickCheck                   as QC
+
+dupFolder :: (Eq a, Eq b) => Context a b -> [Context a b] -> [Context a b]
+dupFolder cont ns = unique cont : ns
+  where unique (a, b, c, d) = (nub a, b, c, nub d)
+
+-- | Remove duplicates.
+rDups :: (Eq a, Eq b) => Gr a b -> Gr a b
+rDups g = G.buildGr $ G.ufold dupFolder [] g
+
+-- | Gen instance to create an arbitrary edge, where the edges are limited by
+-- `n` that is passed to it.
+arbitraryEdge :: (Arbitrary e) => Int -> Gen (LEdge e)
+arbitraryEdge n = do
+  x <- with $ \a -> a < n && a > 0 && a /= n - 1
+  y <- with $ \a -> x < a && a < n && a > 0
+  z <- QC.arbitrary
+  return (x, y, z)
+  where
+    with = QC.suchThat $ QC.resize n QC.arbitrary
+
+-- | Gen instance for a random acyclic DAG.
+randomDAG :: (Arbitrary l, Arbitrary e, Eq l, Eq e) => Gen (Gr l e) -- ^ The generated graph. It uses Arbitrary to
+                          -- generate random instances of each node
+randomDAG = do
+  list <- QC.infiniteListOf QC.arbitrary
+  l    <- QC.infiniteListOf aE
+  QC.sized (\n -> return . G.mkGraph (nodes list n) $ take (10 * n) l)
+ where
+  nodes l n = zip [0 .. n] $ take n l
+  aE = QC.sized arbitraryEdge
+
+-- | Generate a random acyclic DAG with an IO instance.
+genRandomDAG :: (Arbitrary l, Arbitrary e, Eq l, Eq e) => IO (Gr l e)
+genRandomDAG = QC.generate randomDAG