Download 12_hSecurityRequirements

HIGHER COMPUTER NETWORKING
Lesson 12 Network Security Requirements
Description of computer and network security
requirements (confidentiality, data integrity and
availability).
Description of threats to network security in terms of
passive (monitoring of transmission) and active
(modification of the data stream or the creation of a false
stream) attacks.
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HIGHER COMPUTER NETWORKING
What You Should Know About Security Requirements
Computer and Network Security Requirements
It is required by law (The Data Protection Act) that all data held
about individuals must be protected from unauthorised
access.
Confidentiality - All network data must be kept confidential. This
can be for commercial as well as security reasons.
Data Integrity - All network data must be secure from
corruption, data loss and has to be correct and up to date.
Availability - All network data must be available to authorised
users only, but on demand! Network security systems have to
be effective but must also allow immediate authorised user
access to data.
McLean 2006
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HIGHER COMPUTER NETWORKING
What You Should Know About Passive & Active Attacks
Threats to network security are classified as Passive or Active
Attacks.
1 Passive Attacks
A passive attack is an attempt to intercept and copy network
data.
Hackers use programs to monitor the transmission of data
travelling on the network, thus threatening the confidentiality
of the data.
Passive attacks often go unnoticed by authorised network users.
The best method of defence against passive attacks is
encryption.
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HIGHER COMPUTER NETWORKING
What You Should Know About Passive & Active Attacks
2 Active Attacks
An active attack is an attempt to damage or destroy network
data.
Hackers often modify the data stream of the network by
diverting data through a computer system which corrupts the
data before sending it on to it’s original destination.
A similar method can be used which uses false data streams i.e.
the data is diverted to a computer which replaces it with false
data which is then sent on to the destination computer.
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