diff --git a/Model/Bip38KeyPair.cs b/Model/Bip38KeyPair.cs
index 3765147..464b748 100644
--- a/Model/Bip38KeyPair.cs
+++ b/Model/Bip38KeyPair.cs
@@ -255,11 +255,11 @@ private KeyPair decryptUsingIntermediate(Bip38Intermediate intermediate, byte[]
         /// Encryption constructor (non-EC-multiply)
         /// </summary>
         public Bip38KeyPair(KeyPair key, string passphrase) {
-            if (passphrase == null && passphrase == "") {
+            if (passphrase == null || passphrase == "") {
                 throw new ArgumentException("Passphrase is required");
             }
 
-            if (key == null) throw new ArgumentException("Passphrase is required");
+            if (key == null) throw new ArgumentException("Key is required");
 
             this.IsCompressedPoint = key.IsCompressedPoint;
             this._addressType = key.AddressType;