Computer Security Questions and Answers

Answer: D

Correct answer: mutation engine

The part of a polymorphic virus that generates the random key and rewrites the encrypted body is called the mutation engine. The other three names are not used.

Answer: D

Correct answer: All of the above

Word supports all three kinds: command macros that replace a built-in command and run when it is invoked, auto macros that run on events such as opening or closing a document, and the AutoExec macro that runs when Word itself starts. Each gives a macro virus a way to execute without the user choosing to run anything.

Answer: B

Correct answer: encryption

Encryption transforms data by a reversible algorithm so that it is unreadable without the key, and readable again once the transformation is undone. Compression also alters data reversibly but its purpose is to reduce size, not to conceal; biometrics identifies people and ergonomics concerns workplace design.

Answer: A

Correct answer: ii, i, iv and iii

A virus passes through four phases in order: it lies dormant after infection, then propagates copies of itself into other programs, then is triggered by some event, and only then executes its payload. Spreading before acting is what makes a virus dangerous, so propagation must precede execution.

Answer: D

Correct answer: malware

Malware is the contraction of malicious software, and it covers viruses, worms, trojans, spyware and ransomware alike. The other three words are not terms in use.

Answer: B

Correct answer: Confidentiality

Confidentiality, or privacy, is exactly the expectation that nobody but the intended receiver can read the message. Integrity, authentication and nonrepudiation are the other three services and answer different questions.

Answer: A

Correct answer: Message Nonrepudiation

Nonrepudiation means the sender cannot later deny having sent the message. A digital signature provides it, because only the sender's private key could have produced the signature.

Answer: A

Correct answer: Message authentication code

A MAC is a hash computed with a secret key, so it proves both that the message is unaltered and that it came from someone holding the key - integrity and authentication together.

Answer: B

Correct answer: Computer Virus

Self-replication is the defining property of a virus: it copies itself into other programs, and those copies spread when the host programs are run or shared. A pen drive can carry a virus but does not replicate anything itself.

Answer: A

Correct answer: Lock the computer with a password

Locking the session requires the password to be re-entered before anything can be reached, so it protects the data. A screen saver only hides the screen and turning off the monitor only darkens it - in both cases everything remains open to anyone who touches the keyboard.