Security models by giving striking analogies to the real world
A classical case study: (With due acknowledgements to the security exponent who proposed this theory.) He has carefully classified the security models by giving striking analogies to the real world in the form of the five generalised examples that happen to everyone during day-to-day activities:
• The Open House: In this case, the front door and all the rooms are unlocked. Visitors will be free to move around anywhere from any room to any room. This resembles an unprotected site where users do not require any special authentication to view the information.
• The Owner: A case where the front door is locked but all the rooms are unlocked. The owner lives in the house and locks the front door in order to keep the neighbours out but once anyone gets into the house, they will be free to go into all other rooms. This is a useful security model if any company gets a lot of outsiders (i.e., customers, visitors, consultants, etc.) passing through but only want to have its employees access the site.
• The Garden Party: An excellent case in which the front door is unlocked but certain rooms inside the house are locked. Anyone may wish to allow people to help themselves to the bar on the front lawn and get into the washrooms but not necessarily into the bedrooms where the owner has kept all of his personal things.
• The Paying Guest: This is a more stringent measure than the above in which the front door is locked and certain rooms are locked. The guest has a key to enter the house and is able to get into his room only but the other rooms are off his limits. This model will verify whether or not a user should be allowed to enter the site. Once this user is authenticated, only then may he or she move freely throughout the other rooms as long as s/he has access to them.
- The Fort: A locked massive iron gate with barbed wire, front door locked, all rooms also locked, and there is a watchman guarding the house. Simple, unless the users have the proper credentials or certificates or entry passes, they will not be allowed to get in.
Anyone can select any of the above security models or a combination of them. While selecting, it should be borne deep in the mind that every model has its own cost factor and other considerations.