Secure%20Public%20Instant%20Messaging%20(IM):%20A%20Survey

1
Secure Public Instant Messaging (IM) A Survey

• Mohammad Mannan
• Paul C. Van Oorschot
• Digital Security Group
• School of Computer Science
• Carleton University, Ottawa, Canada

2
Whats This Talk About?

• Do we need secure IM?
• Do the current methods provide enough security
  for IM?

3
Organization

• Scope and background
• Whats at stake?
• Reasons why IM is insecure
• Existing IM security mechanisms
• Shortcomings
• Concluding remarks

4
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

5
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 email more than
  IM
• Ferris Report (business IM users)
• 10 million in 2002
• 182 million in 2007

6
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 1
Client 2
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Whats 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 2003
• 34.8 billion spam email messages in 2004
• Compromised systems

8
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

9
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.

10
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 email security solutions for IM?
• Proprietary protocols
• P2P connections

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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)

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

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Thanks.

• Paper http//www.scs.carleton.ca/mmannan/publica
  tions/pst04.pdf
• Presentation http//www.scs.carleton.ca/mmannan/
  publications/pst04.ppt

15
Web References

• Symantec IM Worms Could Spread In Seconds, June
  2004, http//www.techweb.com/wire/story/TWB2004061
  8S0007
• Look out spam, here comes spim, Mar. 2004,
  http//www.theregister.co.uk/2004/03/31/look_out_s
  pam_here_comes
• Microsoft warns of JPEG threat, Sep. 2004
  http//www.macworld.co.uk/news/index.cfm?NewsID96
  35Page1pagePos2
• National Cyber Security Alliance Perception Poll
  Release
• http//www.staysafeonline.info/news/NCSAPerceptio
  nPollRelease.pdf

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Related Work

• Much work on feature enhancement, analysis
• Secure Instant Messaging Protocol Preserving
  Confidentiality against Administrator, Kikuchi
  et al., March, 2004.
• Threats to Instant Messaging, Symantec Security
  Response, 2003.