Authentication Center

What Does Authentication Center Mean?

The authentication center (AuC) is a key component of a global system for mobile communications (GSM) home locator register (HLR). The AuC validates any security information management (SIM) card attempting network connection when a phone has a live network signal.


The AuC provides security to ensure that third parties are unable to use network subscriber services.

Techopedia Explains Authentication Center

Each network SIM card is assigned an individual authentication key (Ki). A matching Ki is contained in the AuC. The SIM and the AuC store the Ki in an unreadable format. The Ki even remains hidden from the SIM card owner to protect network operators from fraud, such as SIM cloning, through enabling user identity verification and ensuring call confidentiality.

During the authentication process, the Ki is used with the subscriber’s international mobile subscriber identity (IMSI) number. Network and service subscriber validity is determined by successful authentication.

The authentication process begins when a subscriber requests a network signal. A randomly selected key is generated that encrypts all wireless communication between the mobile device and the core network. The encryption algorithm is known as A3.

The encrypted randomly chosen number (RAND) using the Ki must match the stored number in the AuC and the SIM card. The entire process is completed during a wireless connection. If the numbers do not match, the authentication is invalidated as a failed function request.


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Margaret Rouse

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.