Alice and Bob, who the FOCI are they?: Analysis of end-to-end encryption in the LINE messaging application


Antonio M. Espinoza, William J. Tolley, and Jedidiah R. Crandall, UNM; Masashi Crete-Nishihata and Andrew Hilts, Citizen Lab


End-to-end encryption (E2EE) is becoming a standard feature in many popular chat apps, but independent security assessments of these implementations are limited. In this paper we provide the first independent analysis of E2EE features in LINE, a messaging application popular in Asian markets, and identify a replay attack and an attack on a lack of forward secrecy. Based on our analysis and communications with LINE about the vulnerabilities we discuss challenges and new research directions to better bridge vendors, researchers, and end-users around security issues.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {205922,
author = {Antonio M. Espinoza and William J. Tolley and Jedidiah R. Crandall and Masashi Crete-Nishihata and Andrew Hilts},
title = {Alice and Bob, who the {FOCI} are they?: Analysis of end-to-end encryption in the {LINE} messaging application},
booktitle = {7th {USENIX} Workshop on Free and Open Communications on the Internet ({FOCI} 17)},
year = {2017},
address = {Vancouver, BC},
url = {},
publisher = {{USENIX} Association},