Extending a secure development methodology to distributed systems

1
Extending a secure development methodology to
distributed systems

• Yamile Villafuerte
• Florida Atlantic University
• Advisor Eduardo B. Fernandez

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Agenda

• Methodology Overview
• Extending the methodology to distributed
  applications
• Financial Institution Example
• Conclusions

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Methodology Overview

• Security principles must be applied at every
  development stage
• Requirements List of all possible attacks.
  Deduce policies to mitigate attacks.
• Analysis Analysis patterns with predefined
  authorizations based on roles.
• Design Interfaces can be used to enforce
  authorizations. Distribution provides another
  dimension where security restrictions can be
  applied.

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Extending the Methodology
Choices at the design stage for distributed
applications
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Extending the Methodology

• How can we keep consistency of the security
  constraints across all development stages?
• How can we represent security constraints in the
  lower levels?
• What are the implications of wireless devices in
  our design models?
• Representation using UML deployment diagrams

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Wireless Devices Challenges

• Limitations
• Limited power
• Limited communications bandwidth
• Limited processing power
• Relatively unreliable network connection
• Mobile
• Tend to get destroyed accidentally or maliciously
• Have effect on security

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Mapping I
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Mapping II

• XACML will allow us to express the security
  constraints defined in the conceptual model in
  XML
• Simplified versions of security standards.

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Authorization rule using XACML
"Permit manager to open account." There is a lot
of XML notation there, but essentially the rule
permits a specific subject, to perform a specific
action against a specific resource.
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A Financial Institution Example
Use Case Diagram
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Analysis Model with RBAC Authorization
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Design Model
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Correspondence of Rights

• Rights defined for Customer (subject)
• Views and wireless devices received a subset of
  these rights.
• Example Wireless device can not download a
  complete list of transactions (limited number of
  records), but can read balance.

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Correspondence of Rights
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Conclusions and future work

• We presented some ideas of how to map
  applications and security constraints defined in
  the analysis stage.
• More work needs to be done to elaborate
  simplified versions of the security standards for
  web services and to map distribution and
  hardware.