Trusted Path Client-server applications

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Trusted Path Client-server applications

• Using COTS components
• Tommy Kristiansen
• tommy_at_the-wildbunch.net

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Agenda

• Thesis
• Contributions
• Solution
• Result
• Questions

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Background

• Bruce Schneier believes that "semantic attacks"
  are the next wave of attacks to be faced by
  computer users. These violate integrity and
  authenticity of data presented to the user,
  enticing him to perform actions benefiting the
  malfactor. Examples of direct user interactions
  where this threat can be found are online voting,
  online gambling, electronic signatures and
  financial transactions etc.

thesis Contributions Solution Result
Questions
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Trusted Path

• Orange Book

A mechanism by which a person at a terminal can
communicate directly with the Trusted Computing
Base. This mechanism can only be activated by the
person or the Trusted Computing Base and cannot
be imitated by untrusted software. Validates to
B2 but are often implemented even when not
validated to B2 e.g. Windows NT C2. The trusted
path mechanism guarantees that data typed by a
user on a client keyboard is protected from any
intrusion by unauthorized programs. It allows a
user to create a non-forgeable and non-penetrable
communication path between the users client and
the trusted operating system software.
thesis Contributions Solution Result
Questions
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Trusted path with COTS

• Built on Hanno Langwegs work
• He looked at this with Client applications.
• Using Delphi to create a ActiveX Control where we
  use DirectX components to create a secure
  environment on a win32 platform.
• Hopefully this will give authenticity and
  integrity of the user and server.

thesis Contributions Solution Result
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Why use DirectX

• When we use DirectX DirectInput and DirectDraw no
  other program can interfere with them run in
  exclusive mode.
• When we use DirectInput, there must be a user
  present to give input
• Eliminates synthesizing
• Gives authenticity of a user.
• When we use DirectDraw no other program can
  interfere with the integrity of what you see.

thesis Contributions Solution Result
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Why use ActiveX

• Easy to implement DirectX components
• No effort for the user to use it.
• Trusted by OS
• Signed ActiveX control
• So youll have an trusted application that you
  need to verify origin of when installing the
  control.

thesis Contributions Solution Result
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Hench

• SendInput
• Screen capture applications
• User permissions installing ActiveX

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Goals with thesis

• See if its possible to create such solution
• Look at existing solution to prevent phishing and
  compare them with this solution.
• Look at the possibilities of implementing this in
  other environments.

thesis Contributions Solution Status
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Contributions

• Provide software developers with a
  server-distributed component to establish
  integrity and authenticity with a local human
  user.
• Use existing software-based technology and
  operating system mechanisms to implement a
  trusted path without additional expensive
  hardware.
• Analyze and compare the security of this approach
  and alternatives.
• Build a working prototype for an existing general
  purpose operating system.
• Prevents phishing attacks
• More secure under login/sigin
• Prevent effectiveness of Trojan horse/Malware
• Does not prevent keylogging!!

thesis Contributions Solution Status
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Contributions

• Assuming
• We can trust the OS(a assumption we already have
  when using e.g. e-banking)
• That the connection between client-server is
  secure e.g. SSL
• Trojan horse and Malware
• Is on top of the OS and only have the same rights
  as the user (no adm).

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Solution
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Results

• Gives advantages compared with existing
  solutions.
• Limitations due to platform
• Found some other interesting platform to see if
  similar solutions are possible.

thesis Contributions Solution Result
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Questions ?
thesis Contributions Solution Status
Questions