Answer:
Advanced persistent threat.
Explanation:
Advanced persistent threat is a threat actor implemented by either a government supported or private group to intrude a network or system and stays undetected, collecting information over a period of time.
It is used by cyber terrorist group to facilitate massive attacks based on the information retrieved. National or government group use the concept to promote national security.
Answer:
uses third party CAs to validate a user's identity
Explanation:
The Digital Certificate is the only means that technically and legally guarantees the identity of a person on the Internet. This is an essential requirement for institutions to offer secure services over the Internet. Further:
The digital certificate allows the electronic signature of documents The recipient of a signed document can be sure that it is the original and has not been tampered with and the author of the electronic signature cannot deny the authorship of this signature.
The digital certificate allows encryption of communications. Only the recipient of the information will be able to access its content.
B
Explanation:
The Alter command is used when we want to modify a database or object contain in database.