Access Control
One familiar use of authentication and authorization is access control. A computer system that is supposed to be used only by those authorized must attempt to detect and exclude the unauthorized. Access to it is therefore usually controlled by insisting on an authentication procedure to establish with some degree of confidence the identity of the user, granting privileges established for that identity. Common examples of access control involving authentication include:
- Asking for photoID when a contractor first arrives at a house to perform work.
- Using captcha as a means of asserting that a user is a human being and not a computer program.
- A computer program using a blind credential to authenticate to another program
- Entering a country with a passport
- Logging in to a computer
- Using a confirmation E-mail to verify ownership of an e-mail address
- Using an Internet banking system
- Withdrawing cash from an ATM
In some cases, ease of access is balanced against the strictness of access checks. For example, the credit card network does not require a personal identification number for authentication of the claimed identity; and a small transaction usually does not even require a signature of the authenticated person for proof of authorization of the transaction. The security of the system is maintained by limiting distribution of credit card numbers, and by the threat of punishment for fraud.
Security experts argue that it is impossible to prove the identity of a computer user with absolute certainty. It is only possible to apply one or more tests which, if passed, have been previously declared to be sufficient to proceed. The problem is to determine which tests are sufficient, and many such are inadequate. Any given test can be spoofed one way or another, with varying degrees of difficulty.
Read more about this topic: Authentication
Famous quotes containing the words access and/or control:
“Knowledge in the form of an informational commodity indispensable to productive power is already, and will continue to be, a major—perhaps the major—stake in the worldwide competition for power. It is conceivable that the nation-states will one day fight for control of information, just as they battled in the past for control over territory, and afterwards for control over access to and exploitation of raw materials and cheap labor.”
—Jean François Lyotard (b. 1924)
“For the mother who has opted to stay home, the question remains: Having perfected her role as a caretaker, can she abdicate control to less practiced individuals? Having put all her identity eggs in one basket, can she hand over the basket freely? Having put aside her own ambitions, can she resist imposing them on her children? And having set one example, can she teach another?”
—Melinda M. Marshall (20th century)