Message Headers Not Encrypted

private void sendDown(Event evt) throws Exception {
...
        EncryptHeader hdr=new EncryptHeader(EncryptHeader.ENCRYPT, getSymVersion());
        hdr.encrypt_entire_msg=this.encrypt_entire_message;

        if(encrypt_entire_message) {
            byte[] serialized_msg=Util.streamableToByteBuffer(msg);
            byte[] encrypted_msg=encryptMessage(symEncodingCipher,
                                                serialized_msg,
                                                0,
                                                serialized_msg.length);
            Message tmp=msg.copy(false); // we need to preserve headers which may already be present
            tmp.setBuffer(encrypted_msg);
            if(tmp.getSrc() == null)
                tmp.setSrc(local_addr);
            tmp.putHeader(this.id, hdr);
            passItDown(new Event(Event.MSG, tmp));
            return;
        }
...
}