Confidentiality is a mechanism that ensures that only the intended and authorized recipients are able to read data. The data is so encrypted that even if an unauthorized user gets access to it, he will not get any meaning out of it. Answer option A is incorrect. In information security, integrity means that data cannot be modified without authorization. This is not the same thing as referential integrity in databases. Integrity is violated when an employee accidentally or with malicious intent deletes important data files, when a computer virus infects a computer, when an employee is able to modify his own salary in a payroll database, when an unauthorized user vandalizes a web site, when someone is able to cast a very large number of votes in an online poll, and so on. There are many ways in which integrity could be violated without malicious intent. In the simplest case, a user on a system could mis-type someone's address. On a larger scale, if an automated process is not written and tested correctly, bulk updates to a database could alter data in an incorrect way, leaving the integrity of the data compromised. Information security professionals are tasked with finding ways to implement controls that prevent errors of integrity. Answer option B is incorrect. Data availability is one of the security principles that ensures that the data and communication services will be available for use when needed (expected). It is a method of describing products and services availability by which it is ensured that data continues to be available at a required level of performance in situations ranging from normal to disastrous. Data availability is achieved through redundancy, which depends upon where the data is stored and how it can be reached. Answer option D is incorrect. Authentication is the act of establishing or confirming something (or someone) as authentic, i.e., the claims made by or about the subject are true ("authentification" is a variant of this word).

The Receive command is used to allocate a receiving buffer associated with the specified connection. An error is returned if no OPEN precedes this command or the calling process is not
authorized to use this connection.
Answer option A is incorrect. The Send command causes the data contained in the indicated user
buffer to be sent to the indicated connection.
Answer option C is incorrect. The Abort command causes all pending SENDs and RECEIVES to
be aborted.
Answer option B is incorrect. The Close command causes the connection specified to be closed.

The biometric technique that authenticates individuals by analyzing the layer of blood vessels at the back of their eyes is Retina Scanning. This method uses the unique patterns of the retinal blood vessels for identification, which are stable and distinctive to each person. Retina scanning involves shining a low-intensity light source through an optical coupler to scan the retina's unique patterns123.