Mobile App Authentication With SAP MII SOAP Service

Dear Experts,

I am trying to create a native android application that will consume SAP MII Transaction SOAP web service.

Regarding that I have one question below.

Question:

How can a Third party android mobile app can consume a Transaction SOAP Webservice of SAP MII without using IllumLoginName and IllumLoginPassword ?

WSDL -  "http://server:port/XMII/WSDLGen/FullTransactionpath and TransactionName?IllumLoginName=username&IllumLoginPassword=password"

Reason for this question is :

1.  As these credentials can expire monthly or can be changed then the change would be require at Android App code.

2. They will be hard coded in code as well.

So is it the right way to consume SOAP service on security point of view. ?

Your response will be highly appreciated.

Thanks,

Anshul Arora