In an analog cellular structure, what is needed to establish a valid authentication?
To establish a valid authentication in an analog cellular structure, the following components are typically needed:
1. Subscriber Identity Module (SIM): A SIM card is a small, removable smart card that stores important subscriber information, such as the unique IMSI (International Mobile Subscriber Identity) number, authentication algorithms, and encryption keys.
2. Authentication Center (AuC): The AuC is a central database that securely stores subscriber information, authentication data, and encryption keys. It generates a unique session key for each authenticated connection.
3. Visitor Location Register (VLR): The VLR is a database that keeps track of subscribers currently present in a given location area. It identifies, authenticates, and authorizes the subscriber during registration.
4. Mobile Switching Center (MSC): The MSC acts as a central hub for call routing, switching, and mobility management. It facilitates communication between different networks and handles authentication requests and responses.
The authentication process usually involves the following steps:
1. Subscriber Registration: When a subscriber turns on their mobile device or moves into a new location area, the device registers with the cellular network. The MSC sends a registration request to the VLR.
2. Authentication Request: The VLR sends an authentication request to the MSC, containing the subscriber's IMSI.
3. Authentication Center Verification: The MSC forwards the authentication request to the AuC, which verifies the IMSI and generates a challenge request.
4. Challenge Request: The MSC sends the challenge request to the subscriber's device through the Base Transceiver Station (BTS). The challenge request typically consists of a random number.
5. Authentication Response: The subscriber's SIM card uses its authentication algorithms and the algorithms stored in the AuC to compute a response to the challenge. The response is sent back to the MSC.
6. Authentication Verification: The MSC forwards the response to the AuC for verification. The AuC compares the response with the expected value.
7. Authentication Result: If the response matches the expected value, the subscriber is deemed authentic, and a session key is generated. The MSC updates the VLR with the subscriber's authentication status, allowing access to network services.
It's worth noting that analog cellular structures are relatively outdated, and most modern cellular networks have transitioned to digital technologies like GSM, 3G, and 4G/LTE, which offer more secure and efficient authentication methods.