Computer Security and Cryptography Essay Example

Computer security and cryptography

A computer program 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, thence granting those privileges as may be authorized to that identity. Common examples of access control involving authentication include: * A captcha is 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. Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to remain accessible and productive to its intended users. The term computer system security means the collective processes and mechanisms by which sensitive and valuable information and services are protected from publication, tampering or collapse by unauthorized activities or untrustworthy individuals and unplanned events respectively. The