Java Security

We get this error intermittently.

2007-07-27 22:32:05,710 INFO [STDOUT] java.lang.IllegalStateException: Cipher not initialized
2007-07-27 22:32:05,710 INFO [STDOUT] at javax.crypto.Cipher.c(DashoA12275)
2007-07-27 22:32:05,710 DEBUG 2007-07-27 22:32:05,710 INFO [STDOUT] at javax.crypto.Cipher.doFinal(DashoA12275)

We have a browser based application where we encrypt and decrypt certain sensitive data. We use the following two functions to do the same

public static String encryptData(String inputData) {
String output = null;
try {
byte[] data = inputData.getBytes();
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] result = cipher.doFinal(data);
output = Base64.encodeBytes(result, Base64.GZIP | Base64.DONT_BREAK_LINES);
} catch (InvalidKeyException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (IllegalBlockSizeException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (BadPaddingException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch(Exception e) {
e.printStackTrace();
}
return output;
}

public static String decryptData(String inputData) {
String output = null;
try {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] encdata = (byte[])Base64.decode(inputData);
byte[] original = cipher.doFinal(encdata);
output = new String(original);
} catch (InvalidKeyException e) {
log.error("decryptData-->InvalidKeyException Caught");
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (IllegalBlockSizeException e) {
log.error("decryptData-->IllegalBlockSizeException Caught");
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (BadPaddingException e) {
log.error("decryptData-->BadPaddingException Caught");
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (Exception e) {
log.error("decryptData-->Exception Caught");
e.printStackTrace();
}
return output;
}

Please let me know, if you have any suggestions

Thanks in Advance,

Devendra