diff --git a/src/main/java/com/jcraft/jsch/KeyPairDeferred.java b/src/main/java/com/jcraft/jsch/KeyPairDeferred.java
index a2a5c2d4..b0dabaff 100644
--- a/src/main/java/com/jcraft/jsch/KeyPairDeferred.java
+++ b/src/main/java/com/jcraft/jsch/KeyPairDeferred.java
@@ -5,7 +5,7 @@
 import java.util.Arrays;
 
 /**
- * A {@link KeyPair} which can only reveal its type and content after it was decrypted using KeyPairDeferred{@link #decrypt(byte[])}.
+ * A {@link KeyPair} which can only reveal its type and content after it was decrypted using {@link com.jcraft.jsch.KeyPairDeferred#decrypt(byte[])}.
  * This is needed for openssh-v1-private-key format.
  */
 public class KeyPairDeferred extends KeyPair {
@@ -72,62 +72,62 @@ void generate(int key_size) throws JSchException {
 
     @Override
     byte[] getBegin() {
-        return delegate.getBegin();
+        return requireDecrypted(delegate).getBegin();
     }
 
     @Override
     byte[] getEnd() {
-        return delegate.getEnd();
+        return requireDecrypted(delegate).getEnd();
     }
 
     @Override
     int getKeySize() {
-        return delegate.getKeySize();
+        return requireDecrypted(delegate).getKeySize();
     }
 
     @Override
     public byte[] getSignature(byte[] data) {
-        return delegate.getSignature(data);
+        return requireDecrypted(delegate).getSignature(data);
     }
 
     @Override
     public byte[] getSignature(byte[] data, String alg) {
-        return delegate.getSignature(data, alg);
+        return requireDecrypted(delegate).getSignature(data, alg);
     }
 
     @Override
     public Signature getVerifier() {
-        return delegate.getVerifier();
+        return requireDecrypted(delegate).getVerifier();
     }
 
     @Override
     public Signature getVerifier(String alg) {
-        return delegate.getVerifier(alg);
+        return requireDecrypted(delegate).getVerifier(alg);
     }
 
     @Override
     public byte[] forSSHAgent() throws JSchException {
-        return delegate.forSSHAgent();
+        return requireDecrypted(delegate).forSSHAgent();
     }
 
     @Override
     byte[] getPrivateKey() {
-        return delegate.getPrivateKey();
+        return requireDecrypted(delegate).getPrivateKey();
     }
 
     @Override
     byte[] getKeyTypeName() {
-        return delegate.getKeyTypeName();
+        return requireDecrypted(delegate).getKeyTypeName();
     }
 
     @Override
     public int getKeyType() {
-        return delegate.getKeyType();
+        return requireDecrypted(delegate).getKeyType();
     }
 
     @Override
     boolean parse(byte[] data) {
-        return delegate.parse(data);
+        return requireDecrypted(delegate).parse(data);
     }
 
     @Override
@@ -137,16 +137,22 @@ public byte[] getPublicKeyBlob() {
 
     @Override
     public String getPublicKeyComment() {
-        return delegate.getPublicKeyComment();
+        return requireDecrypted(delegate).getPublicKeyComment();
     }
 
     @Override
     public String getFingerPrint() {
-        return delegate.getFingerPrint();
+        return requireDecrypted(delegate).getFingerPrint();
     }
 
     @Override
     public boolean isEncrypted() {
         return delegate != null ? delegate.isEncrypted() : super.isEncrypted();
     }
+
+    private <T> T requireDecrypted(T obj) {
+        if (obj == null)
+            throw new IllegalStateException("encrypted key has not been decrypted yet.");
+        return obj;
+    }
 }
diff --git a/src/test/java/com/jcraft/jsch/KeyPairTest.java b/src/test/java/com/jcraft/jsch/KeyPairTest.java
index 296c3a85..8687e9a1 100644
--- a/src/test/java/com/jcraft/jsch/KeyPairTest.java
+++ b/src/test/java/com/jcraft/jsch/KeyPairTest.java
@@ -11,15 +11,16 @@
 import java.net.URISyntaxException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Objects;
 import java.util.stream.Stream;
 
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.jupiter.api.Assertions.*;
 
 class KeyPairTest {
 
-    @TempDir public Path tmpDir;
+    @TempDir
+    public Path tmpDir;
 
     @BeforeAll
     static void init() {
@@ -41,21 +42,20 @@ static Stream<Arguments> keyArgs() {
                 // encrypted dsa
                 Arguments.of("encrypted_openssh_private_key_dsa", "secret123", "ssh-dss"),
                 // ecdsa EC private key format
-                Arguments.of("docker/id_ecdsa256", null, null), //
-                Arguments.of("docker/id_ecdsa384", null, null), //
-                Arguments.of("docker/id_ecdsa521", null, null),
-                Arguments.of("docker/ssh_host_ecdsa256_key", null, null),
-                Arguments.of("docker/ssh_host_ecdsa384_key", null, null),
-                Arguments.of("docker/ssh_host_ecdsa521_key", null, null),
+                Arguments.of("docker/id_ecdsa256", null, "ecdsa-sha2-nistp256"), //
+                Arguments.of("docker/id_ecdsa384", null, "ecdsa-sha2-nistp384"), //
+                Arguments.of("docker/id_ecdsa521", null, "ecdsa-sha2-nistp521"),
+                Arguments.of("docker/ssh_host_ecdsa256_key", null, "ecdsa-sha2-nistp256"),
+                Arguments.of("docker/ssh_host_ecdsa384_key", null, "ecdsa-sha2-nistp384"),
+                Arguments.of("docker/ssh_host_ecdsa521_key", null, "ecdsa-sha2-nistp521"),
                 // encrypted ecdsa
-                Arguments.of("encrypted_openssh_private_key_ecdsa", "secret123", null)
-
+                Arguments.of("encrypted_openssh_private_key_ecdsa", "secret123", "ecdsa-sha2-nistp256")
         );
     }
 
     @ParameterizedTest
     @MethodSource("keyArgs")
-    void loadKey(String path, String password, String publicKeyType) throws URISyntaxException, JSchException {
+    void loadKey(String path, String password, String keyType) throws URISyntaxException, JSchException {
         final JSch jSch = new JSch();
         final String prvkey = Paths.get(ClassLoader.getSystemResource(path).toURI()).toFile().getAbsolutePath();
         assertTrue(new File(prvkey).exists());
@@ -66,6 +66,7 @@ void loadKey(String path, String password, String publicKeyType) throws URISynta
                 jSch.addIdentity(prvkey);
             }
         });
+        assertEquals(keyType, jSch.getIdentityRepository().getIdentities().get(0).getAlgName());
     }
 
     @Test
@@ -86,4 +87,16 @@ void genKeypairEncrypted() {
         });
     }
 
+    @Test
+    void loadAndAcessEncryptedKeyWithoutPassword() throws URISyntaxException, JSchException {
+        final JSch jSch = new JSch();
+        final String prvkey = Paths.get(ClassLoader.getSystemResource("encrypted_openssh_private_key_dsa").toURI()).toFile().getAbsolutePath();
+        assertTrue(new File(prvkey).exists());
+        jSch.addIdentity(prvkey);
+
+        assertThrows(IllegalStateException.class, () -> {
+            jSch.getIdentityRepository().getIdentities().get(0).getAlgName();
+        });
+    }
+
 }