diff --git a/eccrypto.h b/eccrypto.h
index 18572b7b..9b99fc21 100644
--- a/eccrypto.h
+++ b/eccrypto.h
@@ -283,10 +283,10 @@ struct ECNR : public DL_SS<DL_Keys_EC<EC>, DL_Algorithm_ECNR<EC>, DL_SignatureMe
 };
 
 //! Elliptic Curve Integrated Encryption Scheme, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#ECIES">ECIES</a>
-/*! Default to (NoCofactorMultiplication and DHAES_MODE = false) for compatibilty with SEC1 and Crypto++ 4.2.
+/*! Choose NoCofactorMultiplication and DHAES_MODE = false for compatibilty with SEC1 and Crypto++ 4.2.
 	The combination of (IncompatibleCofactorMultiplication and DHAES_MODE = true) is recommended for best
 	efficiency and security. */
-template <class EC, class COFACTOR_OPTION = NoCofactorMultiplication, bool DHAES_MODE = false>
+template <class EC, class COFACTOR_OPTION = NoCofactorMultiplication, bool DHAES_MODE = true>
 struct ECIES
 	: public DL_ES<
 		DL_Keys_EC<EC>,
diff --git a/gfpcrypt.h b/gfpcrypt.h
index ed37bf4a..806c23cc 100644
--- a/gfpcrypt.h
+++ b/gfpcrypt.h
@@ -532,8 +532,8 @@ public:
 		mac.Update(encodingParameters.begin(), encodingParameters.size());
 		if (DHAES_MODE)
 		{
-			byte L[8] = {0,0,0,0};
-			PutWord(false, BIG_ENDIAN_ORDER, L+4, word32(encodingParameters.size()));
+			byte L[8] = {0,0,0,0, 0,0,0,0};
+			PutWord(false, BIG_ENDIAN_ORDER, L, word64(encodingParameters.size()));
 			mac.Update(L, 8);
 		}
 		mac.Final(ciphertext + plaintextLength);
@@ -561,8 +561,8 @@ public:
 		mac.Update(encodingParameters.begin(), encodingParameters.size());
 		if (DHAES_MODE)
 		{
-			byte L[8] = {0,0,0,0};
-			PutWord(false, BIG_ENDIAN_ORDER, L+4, word32(encodingParameters.size()));
+			byte L[8] = {0,0,0,0, 0,0,0,0};
+			PutWord(false, BIG_ENDIAN_ORDER, L, word64(encodingParameters.size()));
 			mac.Update(L, 8);
 		}
 		if (!mac.Verify(ciphertext + plaintextLength))