Storing encrypted passwords on AS400

[Brett Slocum <brett.slocum@xxxxxxxxx>]

I have a Java web application that uses a servlet to store userids and
encrypted passwords, as well as a stored procedure on the AS400 that
checks to see if the password is correct.

I'm having an problem where certain passwords (e.g. 'password99')
always fail when the stored procedure checks the encrypted passwords
against each other.

Below is a code sniplet of the encryption. The String returned gets
stored via JDBC into the AS400.

Is there some issue with storing UTF-8 characters in the DB2 database?
Should I use EBCDIC-US instead?

Any help would be greatly appreciated. Thanks in advance.
-- 
Brett Slocum
<slocum@xxxxxxxxxxxxxx>
---------------------------------------------------------------
Code Sniplet:

    public static String encrypt(String data) {
        String encrypted_Data = null;
        MessageDigest md = null;
        try{
            md = MessageDigest.getInstance("SHA-1");
            md.update(data.getBytes("UTF-8"));
            byte[] result = md.digest();
            encrypted_Data = new String(result, "UTF-8");
        } catch(Exception e) {
            e.printStackTrace();
        }
        return encrypted_Data;
    }