sun.security.jgss.krb5.CipherHelper creates a private desCipher object and caches it.

this caching should not be done. a new Cipher object should be retrieved as needed. the caching can pose problems, for example, in multi-threaded environments since access to the object is not synchronized.
in JGSS workspace, 2 classes -- AesDkCrypto and ArcFourCrypto -- in the sun.security.krb5.internal.crypto.dk package also cache the Cipher in a similar style.