Lawful Interception

Also known as: LI, Lawful Interception

Lawful Intercept (LI) is the legally authorised capability that allows law enforcement agencies to obtain communications content and related metadata from telecom operators under judicial or administrative warrant. Standards such as ETSI TS 102 232 and 3GPP TS 33.126/33.127/33.128 define the handover interfaces, data formats and 5G-specific architecture (LIPF, LICF, MDF2/MDF3) so operators can deliver intercepted traffic securely to authorised agencies.

Categories: Radio Access NetworkSignalingThreats and Attacks

Lawful Intercept 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.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place Lawful Intercept in the wider telecom-security picture, review Lawful Interception Architecture, Lawful Interception, Lawful Interception Abuse Risk, Telecom Penetration Testing, CALEA and GSM: each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

Related topic hubs

  • SS7 Security SS7/MAP/CAP/SCCP attacks and defenses across 2G/3G interconnect.
  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
  • Signaling Firewall Unified SS7/Diameter/GTP/SMS signaling firewall framework.
  • 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.

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.