Secure Public Instant Messaging (IM): A Survey Mohammad Mannan Paul C. Van Oorschot Digital Security Group School of Computer Science Carleton University, Ottawa, Canada

What’s This Talk About? Do we need secure IM? Do the current methods provide enough security for IM?

Organization Scope and background What’s at stake? Reasons why IM is insecure Existing IM security mechanisms Shortcomings Concluding remarks

Scope PC-to-PC (one-to-one) text messaging Popular public and business IM AOL, Yahoo!, and MSN Messenger, ICQ Yahoo! Business Messenger, Reuters Messaging third party clients (Trillian, IMSecure) Out of scope Short Messaging System(SMS) Internet Relay Chat (IRC) chat room/group chat

Background IM is mainly used for – exchanging text messages tracking availability of a list of users Recent statistics Pew report 2004 – 42% Internet users use IM in the U.S. growth rate of IM population: 29% (since 2000) 70% Internet users report using more than IM Ferris Report (business IM users) 10 million in million in 2007

IM Communications Model Client-server: presence, contact list and availability management, message relay between users Client-client: audio/video chat, file transfer Authentication: password-based, sometimes use SSL (Secure Socket Layer) IM Server Client 1Client 2

What’s at Stake? Conversations (privacy and information leakage) Propagation vector for Internet worms, viruses and Trojans SPIM (IM spam) – Unsolicited commercial IMs Radicati Group projections – 1.2 billion SPIMs in 2004 (5% of total IMs) 400 million in billion spam messages in 2004 Compromised systems

Reasons why IM is insecure “Insecure” connection impersonation replay Sharing IM features with other applications Exploitable URI (Uniform Resource Identifiers) handlers aim, ymsgr example: aim://addbuddy?mybuddy attacks buffer overflow scripting attacks Deceitful hyperlinks

Existing IM Security Mechanisms(1) Built-in methods launch anti-virus explicit consent for add contact, file transfer, presence info (not cryptographically protected) new version and critical updates notification prevents automated account creation word filtering password-protected settings etc.

Existing IM Security Mechanisms(2) Third-party security solutions AIM can make use of Class 2 digital certificates IMSecure Trillian Why don't we use security solutions for IM? Proprietary protocols P2P connections

Shortcomings of Current Solutions Anti-virus can check only limited file types URL exploitations Cost and maintenance burden of digital certificates SSL-based (corporate IM) solutions: resource hungry visible messages to server limited threat model (end-points are trusted)

Weaknesses of IMSecure Model IM ClientIMSecureUnprotected Messages Malicious Program Read/Modify Messages Encrypted Messages User System IM Server/ Others

Concluding Remarks IM security is important Current methods are insufficient Can we use existing protocols to secure IM? User interface issues Ongoing work in IETF (see also paper)

Thanks. Paper: Presentation:

Web References Symantec: IM Worms Could Spread In Seconds, June 2004, Look out spam, here comes spim, Mar. 2004, Microsoft warns of JPEG threat, Sep pagePos=2 pagePos=2 National Cyber Security Alliance Perception Poll Release

Related Work Much work on feature enhancement, analysis Secure Instant Messaging Protocol Preserving Confidentiality against Administrator, Kikuchi et al., March, Threats to Instant Messaging, Symantec Security Response, 2003.