diff --git a/cipher/diffiehellman/diffiehellmankeyexchange_test.go b/cipher/diffiehellman/diffiehellmankeyexchange_test.go
index 7fe5ca7b9..ec5a76700 100644
--- a/cipher/diffiehellman/diffiehellmankeyexchange_test.go
+++ b/cipher/diffiehellman/diffiehellmankeyexchange_test.go
@@ -2,10 +2,22 @@ package diffiehellman
 
 import (
 	"crypto/rand"
-	"crypto/rsa"
+	"math/big"
 	"testing"
 )
 
+// randomPrivateKey returns a uniformly random private key in the range
+// [1, primeNumber-1], which is the valid range for a Diffie-Hellman secret.
+func randomPrivateKey(t *testing.T) int64 {
+	t.Helper()
+	// rand.Int returns a value in [0, primeNumber-1); shift by 1 to get [1, primeNumber-1].
+	n, err := rand.Int(rand.Reader, big.NewInt(primeNumber-1))
+	if err != nil {
+		t.Fatalf("failed to generate random private key: %v", err)
+	}
+	return n.Int64() + 1
+}
+
 func TestDiffieHellmanKeyExchange(t *testing.T) {
 	t.Run("Test 1: modularExponentiation", func(t *testing.T) {
 		var want int64 = 9 // (3^5)mod13 = 243mod13 = 9
@@ -20,19 +32,19 @@ func TestDiffieHellmanKeyExchange(t *testing.T) {
 	})
 
 	t.Run("Test 2: Key Exchange", func(t *testing.T) {
-		// generating a small sized rsa_cipher key for testing
-		alicePrvKey, _ := rsa.GenerateKey(rand.Reader, 31)
-		bobPrvKey, _ := rsa.GenerateKey(rand.Reader, 31)
+		// alice and bob each pick a private key
+		alicePrvKey := randomPrivateKey(t)
+		bobPrvKey := randomPrivateKey(t)
 
 		// alice and bob generates their respective share key with their privateKey
-		shareKeyByAlice := GenerateShareKey(alicePrvKey.D.Int64())
-		shareKeyByBob := GenerateShareKey(bobPrvKey.D.Int64())
+		shareKeyByAlice := GenerateShareKey(alicePrvKey)
+		shareKeyByBob := GenerateShareKey(bobPrvKey)
 
 		// generated share key now can be exchanged even via insecure channel
 
 		// mutualKey can be computed using shared key
-		mutualKeyComputedByAlice := GenerateMutualKey(alicePrvKey.D.Int64(), shareKeyByBob)
-		mutualKeyComputedByBob := GenerateMutualKey(bobPrvKey.D.Int64(), shareKeyByAlice)
+		mutualKeyComputedByAlice := GenerateMutualKey(alicePrvKey, shareKeyByBob)
+		mutualKeyComputedByBob := GenerateMutualKey(bobPrvKey, shareKeyByAlice)
 
 		if mutualKeyComputedByAlice != mutualKeyComputedByBob {
 			t.Errorf("mutual key computed by alice and bob should be same, but got un-equal")