Title
Is Bob Sending Mixed Signals?
Abstract
Demand for end-to-end secure messaging has been growing rapidly and companies have responded by releasing applications that implement end-to-end secure messaging protocols. Signal and protocols based on Signal dominate the secure messaging applications. In this work we analyze conversational security properties provided by the Signal Android application against a variety of real world adversaries. We identify vulnerabilities that allow the Signal server to learn the contents of attachments, undetectably re-order and drop messages, and add and drop participants from group conversations. We then perform proof-of-concept attacks against the application to demonstrate the practicality of these vulnerabilities, and suggest mitigations that can detect our attacks. The main conclusion of our work is that we need to consider more than confidentiality and integrity of messages when designing future protocols. We also stress that protocols must protect against compromised servers and at a minimum implement a trust but verify model.
Year
Venue
Field
2017
WPES@CCS
Secure messaging,Internet privacy,Android (operating system),Confidentiality,Computer science,Computer security,Server,End-to-end encryption,Security properties,Secure communication,Vulnerability
DocType
ISBN
Citations 
Conference
978-1-4503-5175-1
3
PageRank 
References 
Authors
0.43
7
3
Name
Order
Citations
PageRank
Michael Schliep151.84
Ian Kariniemi230.43
Nicholas Hopper3146995.76