Answer: ensuring that a system is not changed by a subject that is not authorized to do so
Explanation: Access control refers to pribcues which are employed in the bid thlo ensure the security of data and information. It provides the ability to authenticate and authorize access to information and data thereby preventing unwarranted access and tampering of the information. Integrity in terms of data security and access control is is concerned with modification to an existing or original data by unauthorized sources. When unauthorized addition or subtraction occurs on a data, the integrity of such data has been compromised. Therefore, authorization is required whenever a source is about to access certain information whereby only those with the right authorization code will be allowed, Inputting an incorrect pass code after a certain number of tries may result in system lock down as access control detects a a possible intrusion