Transcript .ppt

CS 5150
Software Engineering
Lecture 18
Security & Privacy
Administrivia
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SE in the News
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Modeling Dynamic Aspects of
Systems
Interaction diagrams: set of objects and their
relationships including messages that may be
dispatched among them
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Sequence diagrams: time ordering of
messages
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Interaction: Informal Bouncing Ball
Diagrams
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UML Notation for Classes and Objects
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Notation: Active Class
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An active class is a class whose objects own
one or more processes or threads and
therefore can initiate control activity. When
instantiated, the class controls its own
execution, rather than being invoked or
activated by other objects.
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Sequence Diagram: Painting
Mechanism
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Core Security Technologies
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Authentication and authorization
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Firewalls
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Encryption
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Authentication and Authorization
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Authentication establishes the identity of an agent:
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What does the agent possess (e.g., smart card)?
Where does the agent have physical access to (e.g.,
crt-alt-del)?
What are the physical properties of the agent (e.g.,
fingerprint)?
Authorization establishes what an authenticated agent
may do:
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What does the agent know (e.g., password)?
Access control lists
Group membership
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Firewalls
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Encryption
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Allows data to be stored and transmitted securely,
even when the bits are viewed by unauthorized
agents and the algorithms are known.
Private key and public key
Digital signatures
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Attack Model
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Rigorous security engineering must be based
on an attack model
Who is the expected attacker?
Why are they interested in attacking the
system?
How do you expect them to attack the system?
What are the consequences of a successful
attack?
In safety-critical systems, attack models
should be part of the earliest phases of the
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CWE Top-25
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http://cwe.mitre.org/top25/index.html
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