1 files changed, 20 insertions, 4 deletions
diff --git a/crypto/src/crypto/engines/RSABlindedEngine.cs b/crypto/src/crypto/engines/RSABlindedEngine.cs
index 7b928c5fb..98108f9b4 100644
--- a/crypto/src/crypto/engines/RSABlindedEngine.cs
+++ b/crypto/src/crypto/engines/RSABlindedEngine.cs
@@ -49,13 +49,29 @@ namespace Org.BouncyCastle.Crypto.Engines
             {
                 ParametersWithRandom rParam = (ParametersWithRandom)param;
 
-                key = (RsaKeyParameters)rParam.Parameters;
-                random = rParam.Random;
+                this.key = (RsaKeyParameters)rParam.Parameters;
+
+                if (key is RsaPrivateCrtKeyParameters)
+                {
+                    this.random = rParam.Random;
+                }
+                else
+                {
+                    this.random = null;
+                }
             }
             else
             {
-                key = (RsaKeyParameters)param;
-                random = new SecureRandom();
+                this.key = (RsaKeyParameters)param;
+
+                if (key is RsaPrivateCrtKeyParameters)
+                {
+                    this.random = new SecureRandom();
+                }
+                else
+                {
+                    this.random = null;
+                }
             }
         }