Jump to content

Failing badly

From Wikipedia, the free encyclopedia
(Redirected from Fail well)

Failing badly and failing well are concepts in systems security and network security (and engineering in general) describing how a system reacts to failure. The terms have been popularized by Bruce Schneier, a cryptographer and security consultant.[1][2]

Failing badly

[edit]

A system that fails badly is one that has a catastrophic result when failure occurs. A single point of failure can thus bring down the whole system. Examples include:

Failing well

[edit]

A system that fails well is one that compartmentalizes or contains its failure. Examples include:

  • Compartmentalized hulls in watercraft, ensuring that a hull breach in one compartment will not flood the entire vessel.
  • Databases that do not allow downloads of all data in one attempt, limiting the amount of compromised data.
  • Structurally redundant buildings conceived to resist loads beyond those expected under normal circumstances, or resist loads when the structure is damaged.
  • Computer systems that restart or proceed to a stopped state when an invalid operation occurs.[3]
  • Access control systems that are locked when power is cut to the unit.[3]
  • Concrete structures which show fractures long before breaking under load, thus giving early warning.
  • Armoured cockpit doors on airplanes, which confine a potential hijacker within the cabin even if they are able to bypass airport security checks.[1]
  • Internet connectivity provided by more than one vendor or discrete path, known as multihoming.
  • Star or mesh networks, which can continue to operate when a node or connection has failed (though for a star network, failure of the central hub will still cause the network to fail).
  • Ductile materials, such as "under-reinforced concrete", when overloaded, fail gradually – they yield and stretch, giving some warning before ultimate failure.
  • Making a backup copy of all important data and storing it in a separate place. That data can be recovered from the other location when either place is damaged.

Designing a system to 'fail well' has also been alleged to be a better use of limited security funds than the typical quest to eliminate all potential sources of errors and failure.[4]

See also

[edit]

References

[edit]
  1. ^ a b Homeland Insecurity Archived 2011-09-28 at the Wayback Machine, Atlantic Monthly, September 2002
  2. ^ David Hillson (29 March 2011). The Failure Files: Perspectives on Failure. Triarchy Press. p. 146. ISBN 9781908009302.
  3. ^ a b Eric Vanderburg (February 18, 2013). "Fail Secure – The right way to fail". PC Security World. Archived from the original on October 27, 2014. Retrieved November 11, 2014.
  4. ^ Failing Well with Information Security Archived 2008-10-14 at the Wayback Machine - Young, William; Apogee Ltd Consulting, 2003