SAFECOM and NCSWIC Release LLA and LLE: Are You Really Secure?


Author: April O’Reilly, Cybersecurity and Infrastructure Security Agency (CISA), Joint SAFECOM-NCSWIC P25 UNWG Federal Lead

Are you really secure when using your land mobile radio?  Most Project 25 (P25) radio systems come with built-in safeguards, but the availability of software key generators and other attack vectors used by threat actors means that new P25 features are needed to maintain P25 communications security. Over the past few years, Link Layer Security (LLS) features such as Link Layer Authentication (LLA) and Link Layer Encryption (LLE) have received increased attention from manufacturers and users looking to improve communications security. LLA and LLE: Are You Really Secure? explains these features, their impact on securing public safety communications, and provides a case study demonstrating why these features should be used to provide additional LMR system safeguards.

While both LLA and LLE sound similar and improve P25 security, they serve different purposes and are in different stages of development and adoption. First included in the P25 Standards in 2005, LLA is available from most radio manufacturers and some infrastructure manufacturers. However, this function has seen limited adoption to date. LLE, on the other hand, is still under standards development and not available on any P25 systems today.

For questions about the LLA and LLE: Are You Really Secure? whitepaper, please contact or visit for additional P25 resources.