diff --git a/Crypto/ECC.hs b/Crypto/ECC.hs
index 576247d..5629bc4 100644
--- a/Crypto/ECC.hs
+++ b/Crypto/ECC.hs
@@ -49,7 +49,7 @@ data KeyPair curve = KeyPair
     }
 
 newtype SharedSecret = SharedSecret ScrubbedBytes
-    deriving (Eq, ByteArrayAccess)
+    deriving (Eq, ByteArrayAccess, NFData)
 
 class EllipticCurve curve where
     -- | Point on an Elliptic Curve
diff --git a/Crypto/ECC/Simple/Types.hs b/Crypto/ECC/Simple/Types.hs
index 653f4c2..814c256 100644
--- a/Crypto/ECC/Simple/Types.hs
+++ b/Crypto/ECC/Simple/Types.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 -- |
 -- Module      : Crypto.ECC.Simple.Types
 -- License     : BSD-style
@@ -98,7 +99,7 @@ data CurveType =
 
 -- | ECC Private Number
 newtype Scalar curve = Scalar Integer
-    deriving (Show,Read,Eq,Data,Typeable)
+    deriving (Show,Read,Eq,Data,Typeable,NFData)
 
 -- | Define a point on a curve.
 data Point curve =
diff --git a/Crypto/PubKey/DH.hs b/Crypto/PubKey/DH.hs
index d066944..152b1b5 100644
--- a/Crypto/PubKey/DH.hs
+++ b/Crypto/PubKey/DH.hs
@@ -35,17 +35,20 @@ data Params = Params
     , params_bits :: Int
     } deriving (Show,Read,Eq,Data,Typeable)
 
+instance NFData Params where
+    rnf (Params p g bits) = rnf p `seq` rnf g `seq` bits `seq` ()
+
 -- | Represent Diffie Hellman public number Y.
 newtype PublicNumber = PublicNumber Integer
-    deriving (Show,Read,Eq,Enum,Real,Num,Ord)
+    deriving (Show,Read,Eq,Enum,Real,Num,Ord,NFData)
 
 -- | Represent Diffie Hellman private number X.
 newtype PrivateNumber = PrivateNumber Integer
-    deriving (Show,Read,Eq,Enum,Real,Num,Ord)
+    deriving (Show,Read,Eq,Enum,Real,Num,Ord,NFData)
 
 -- | Represent Diffie Hellman shared secret.
 newtype SharedKey = SharedKey ScrubbedBytes
-    deriving (Show,Eq,ByteArrayAccess)
+    deriving (Show,Eq,ByteArrayAccess,NFData)
 
 -- | generate params from a specific generator (2 or 5 are common values)
 -- we generate a safe prime (a prime number of the form 2p+1 where p is also prime)
diff --git a/Crypto/PubKey/ECC/P256.hs b/Crypto/PubKey/ECC/P256.hs
index f1d8c32..e227c51 100644
--- a/Crypto/PubKey/ECC/P256.hs
+++ b/Crypto/PubKey/ECC/P256.hs
@@ -58,11 +58,11 @@ import qualified Crypto.Number.Serialize as S (os2ip, i2ospOf)
 
 -- | A P256 scalar
 newtype Scalar = Scalar ScrubbedBytes
-    deriving (Show,Eq,ByteArrayAccess)
+    deriving (Show,Eq,ByteArrayAccess,NFData)
 
 -- | A P256 point
 newtype Point = Point Bytes
-    deriving (Show,Eq)
+    deriving (Show,Eq,NFData)
 
 scalarSize :: Int
 scalarSize = 32