Security Flashcards
Describe the confidentiality component of security
Providing protection from unauthorised access or disclosure
What are the three components of security?
Confidentiality
Integrity
Availability
Describe the integrity component of security
Ensuring that systems and information are complete and free from unauthorised change or modification
Describe the availability component of security
Ensuring that information, services and resources are available when and where required
Security should be regarded as a horizontal / vertical component within an organisational structure
Horizontal
What is the concept of “defence in depth”?
The idea of a series of overlapping protective measures embracing the whole organisation. Each of the controls may be cheap and not necessarily particularly strong, but taken together they integrate to form a total solution.
List some of the component controls of “defence in depth”
Physical security Policies and procedures Personnel security Organisational culture Clear desk policy Document security Audit trails Business continuity
In terms of security, why is it not advisable to rely on one control?
It creates a single point of failure
In defining the controls required in a security system, what three points should be taken into consideration?
- Security is a management issue not an information technology issue
- The controls put in place should not interfere with legitimate business processes
- Users may need to be made aware what the controls are designed to achieve, and trained to maximise the potential effect of the controls
Physical security: what is the first defensive point of any organisation?
The perimeter
Personnel security: what supplements a physical control quite well?
If staff have to show ID on entering the building
Backups. At a minimum, how often should smaller organisations perform backups?
Backup of whole system once a week
Backup of data only, daily
Where should backups be stored?
Off-site
What risk do backups pose in terms of security?
Whereas the original data may be password controlled, the backup may not be protected
With regard to application security, what five controls should be considered to minimise the risk of corruption of operational systems?
Updating operational program libraries should only be performed by the nominated librarian upon management authorisation
If possible, operational systems should only hold executable code
Executable code should not be implemented on an operational system until evidence of successful testing and UAT is obtained
Audit log should be maintained of all updates to operational program libraries
Previous versions of software should be retained as a contingency measure
At what level should vendor-supplied software used in operational systems be maintained?
At a level supported by the supplier
When should physical or logical access to applications be given to suppliers?
For support services when necessary, and with management approval
With regards to application security, what does version control achieve?
It ensures recent versions of the software are not overwritten by earlier versions
With regards to application controls, why should distribution of software be controlled?
So that the number of copies of software do not exceed the number of software licenses held by the organisation.
What six things should operating procedures specify for the detailed execution of each job?
Processing and handling of information
Scheduling requirements, including interdependencies with other systems
Instructions for handling errors or other exceptional conditions
Support contacts in event of unexpected difficulties
Special output handling instructions
System restart and recovery procedures in event of system failure
Documented operating procedures should also be documented for system housekeeping activities such as…
Computer startup and shutdown Backup Equipment maintenance Computer room and mail handling management Safety
Each operational procedure should have an owner who is responsible for what five things?
Writing the original procedure
Maintaining the procedure in the light of operational needs
Ensuring its contents are circulated to relevant staff
Ensuring it is filed in control manual
Removing procedure when no longer required
— — — is a way of reducing the risk of accidental or deliberate system misuse
Segregation of duties
When segregation of duties is difficult due to the small size of an organisation, what should be considered?
Other controls such as monitoring of activities, audit trails and management supervision