2G (Second Generation Mobile Network)

Digital cellular technology introduced in the 1990s, most notably GSM (Global System for Mobile Communications) in Europe and CDMA in the US. 2G enabled SMS text messaging, basic data services, and introduced the first mobile security mechanisms (SIM-based authentication). Data speeds reached up to 14 kbps.

Categories: Radio Access NetworkIdentity and SubscriberSecurity Controls

2G in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) anchor authentication, charging and lawful interception. Any protocol that leaks a permanent identifier is treated as a privacy defect, which is why 5G introduced SUCI concealment on the air interface.

To place 2G in the wider telecom-security picture, review Authentication, IMSI Catcher (Cell Site Simulator), OTA, USIM, WCDMA and SIM Swap — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.