Enrique, Could you take a look at KdcLoginModule and see what it would take to make it not reference some sun. classes. I think some signatures disappeared in JDK 1.5 and is causing the build to fail on 1.5. Here are the two offending lines: line no: 74 EncryptionKey encKey = new EncryptionKey(key.getEncoded()); 75 76 credential = Credentials.acquireTGT(principalName, encKey); These are in o.a.k.kdc.jaas.KdcLoginModule. I'd massage them over myself but I did not know what I could use in their stead. Thanks, Alex