Overview

In this chapter, we discuss the ANSI-41 mobile telecommunications network functions related to authentication. These functions are divided into the following categories: ^[1]

• Shared secret data sharing

• Global challenge

• Unique challenge

• Shared secret data update

• Call-history count update

• Authentication reporting

We also examine the ANSI-41 application processes that support these network functions. In the course of describing the processes, we identify the ANSI-41 mobile application part (MAP) operations (e.g., AuthenticationRequest) used to accomplish authentication process tasks. We summarize this information at the end of the chapter. Note that we employ the ANSI-41 convention for operation component acronyms the Invoke component acronym is in all-capital letters (e.g., AUTHREQ), while the Return Result component acronym is in all-lowercase letters (e.g., authreq). Refer to the ANSI-41 standard for the descriptions of the individual ANSI-41 operations and parameters. Also, consult the Glossary for a description of general terms (e.g., serving system) that are not explicitly defined in this chapter.

Throughout this chapter we generally consider the serving system as a single entity encompassing the mobile switching center (MSC) and visitor location register (VLR) functional entities. This simplifies the descriptions of ANSI-41 application processes and also is representative of a large percentage of the ANSI-41 implementations currently in service. However, ANSI-41 authentication assigns specific processing duties to the VLR that make the concept of sharing a VLR among multiple MSCs a viable alternative to the combined implementation. Therefore, while we describe authentication processes in terms of a single MSC...