Determine whether security is needed for your mobile portal. If so, you must assess what kind is appropriate.
Use these questions to help you identify security requirements for your mobile portal:
Is SSL required for authentication to the portal?
Is SSL required for any other part of the portal?
Is a gateway needed?
What are your security policies?
Do you use the Identity Server software to provide single sign-on to your portal? Will your single sign-on requirements change for mobile access? Should your mobile portal users be able to sign on automatically?