diff --git a/ChangeLog.md b/ChangeLog.md
index 8ef5496f..ddc53f68 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,6 +3,7 @@
   * Tweak OSGi bundle manifest to allow Log4j 3.
   * [#362](https://github.com/mwiede/jsch/issues/362) fix PEM key parsing to work with windows line endings.
   * [#361](https://github.com/mwiede/jsch/issues/361) guard against `UIKeyboardInteractive` implementations that include NULL elements in the `String[]` returned from `promptKeyboardInteractive()`.
+  * Add a default implmentation of the deprecated `decrypt()` method to the `Identity` interface that throws an `UnsupportedOperationException`.
 * [0.2.9](https://github.com/mwiede/jsch/releases/tag/jsch-0.2.9)
   * [#293](https://github.com/mwiede/jsch/issues/293) allow UserAuthNone to be extended.
   * Make JGSS module optional.
diff --git a/src/main/java/com/jcraft/jsch/AgentIdentity.java b/src/main/java/com/jcraft/jsch/AgentIdentity.java
index 2fe5a2bc..3f83e4fb 100644
--- a/src/main/java/com/jcraft/jsch/AgentIdentity.java
+++ b/src/main/java/com/jcraft/jsch/AgentIdentity.java
@@ -60,12 +60,6 @@ public byte[] getSignature(byte[] data, String alg) {
     return agent.sign(blob, data, alg);
   }
 
-  @Override
-  @Deprecated
-  public boolean decrypt() {
-    throw new RuntimeException("not implemented");
-  }
-
   @Override
   public String getAlgName() {
     return algname;
diff --git a/src/main/java/com/jcraft/jsch/Identity.java b/src/main/java/com/jcraft/jsch/Identity.java
index 5aee38c8..f27c36bb 100644
--- a/src/main/java/com/jcraft/jsch/Identity.java
+++ b/src/main/java/com/jcraft/jsch/Identity.java
@@ -83,22 +83,30 @@ public default byte[] getSignature(byte[] data, String alg) {
   }
 
   /**
+   * This method is deprecated and the default implmentation of this method will throw an
+   * {@link UnsupportedOperationException}.
+   *
    * @deprecated The decryption should be done automatically in {@link #setPassphrase(byte[])}
+   * @return <code>true</code> if the decryption is succeeded or this identity is not cyphered.
    * @see #setPassphrase(byte[])
    */
   @Deprecated
-  public boolean decrypt();
+  public default boolean decrypt() {
+    throw new UnsupportedOperationException("not implemented");
+  }
 
   /**
    * Returns the name of the key algorithm.
    *
-   * @return "ssh-rsa" or "ssh-dss"
+   * @return the name of the key algorithm
    */
   public String getAlgName();
 
   /**
    * Returns the name of this identity. It will be useful to identify this object in the
    * {@link IdentityRepository}.
+   *
+   * @return the name of this identity
    */
   public String getName();
 
diff --git a/src/main/java/com/jcraft/jsch/IdentityFile.java b/src/main/java/com/jcraft/jsch/IdentityFile.java
index 89555674..af55a0b4 100644
--- a/src/main/java/com/jcraft/jsch/IdentityFile.java
+++ b/src/main/java/com/jcraft/jsch/IdentityFile.java
@@ -45,7 +45,7 @@ static IdentityFile newInstance(String name, byte[] prvkey, byte[] pubkey,
     return new IdentityFile(name, kpair);
   }
 
-  private IdentityFile(String name, KeyPair kpair) throws JSchException {
+  private IdentityFile(String name, KeyPair kpair) {
     this.identity = name;
     this.kpair = kpair;
   }
@@ -94,30 +94,21 @@ public byte[] getSignature(byte[] data, String alg) {
     return kpair.getSignature(data, alg);
   }
 
-  /**
-   * @deprecated This method should not be invoked.
-   * @see #setPassphrase(byte[] passphrase)
-   */
-  @Override
-  @Deprecated
-  public boolean decrypt() {
-    throw new RuntimeException("not implemented");
-  }
-
   /**
    * Returns the name of the key algorithm.
    *
-   * @return "ssh-rsa" or "ssh-dss"
+   * @return the name of the key algorithm
    */
   @Override
   public String getAlgName() {
-    byte[] name = kpair.getKeyTypeName();
-    return Util.byte2str(name);
+    return kpair.getKeyTypeString();
   }
 
   /**
    * Returns the name of this identity. It will be useful to identify this object in the
    * {@link IdentityRepository}.
+   *
+   * @return the name of this identity
    */
   @Override
   public String getName() {