Authentication forms the foundation of your security infrastructure, and access privileges granted to users (or systems) are predicated on the notion that users are who they claim to be. There are a number of options available to help you do this with SAP systems, including password parameters, secure network communications (SNC), X.509 digital certificates, and Pluggable Authentication Services (PAS), all of which are discussed in this article. But authentication is a must for SAP and non-SAP systems alike — and before you know it, your users are faced with numerous logon prompts from different systems, each requiring different user IDs and passwords. SAP's solution for this is single sign-on (SSO). This article shows you how to use SSO to authenticate users across multiple, standalone SAP systems, and also how the mySAP Workplace can provide SSO for SAP systems and third-party applications across your company's intranet, and even across the Internet.