Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
91
Which of the following is an example of a physical security attack?
Answer:
Tailgating
Tailgating is a physical attack where an unauthorized person follows an authorized individual into a secure, restricted area. The other options are all forms of logical or digital attacks.
92
What is a primary benefit of using a physical security key for MFA?
Answer:
It is completely immune to phishing attacks.
Phishing attacks often rely on tricking a user into entering their password and OTP code into a fake website. A FIDO-based security key will not work on a fake site because it authenticates directly with the legitimate website's domain, making it a "phish-proof" form of MFA.
93
An IPS that is configured to be "fail-open" will do what in the event of a system malfunction?
Answer:
Allow all network traffic to pass through without inspection.
A "fail-open" configuration prioritizes availability. If the IPS device fails, it effectively becomes a simple wire, allowing all traffic to pass through so that the network connection is not lost. The opposite is "fail-closed," which would block all traffic, prioritizing security over availability.
94
A bank's ATM requires you to have your debit card ("something you have") and enter your PIN ("something you know"). This is a real-world example of:
Answer:
Multi-factor authentication
This is one of the oldest and most common examples of MFA. It combines a possession factor (the card) with a knowledge factor (the PIN) to provide strong security for transactions.
95
What is a "key exchange" protocol, such as Diffie-Hellman, used for?
Answer:
To allow two parties to securely establish a shared secret key over an insecure public channel.
The Diffie-Hellman key exchange is a fundamental cryptographic protocol that solves the problem of sharing a secret key for symmetric encryption. It allows two parties, who have no prior knowledge of each other, to jointly establish a shared secret over a network that may be monitored by an attacker.
96
What is "quantum cryptography"?
Answer:
The use of quantum-mechanical phenomena, like quantum entanglement, to perform cryptographic tasks.
Quantum cryptography uses the principles of quantum physics to create a provably secure communication channel. For example, in quantum key distribution (QKD), any attempt to eavesdrop on the key exchange would disturb the quantum state, which would be detected by the legitimate parties.
97
The RSA algorithm's security is based on the computational difficulty of what mathematical problem?
Answer:
Factoring large prime numbers.
The security of RSA relies on the fact that it is easy to multiply two large prime numbers together, but it is extremely difficult and time-consuming for a classical computer to do the reverse—that is, to find the original prime factors of a very large number.
98
What is the main disadvantage of symmetric encryption compared to asymmetric encryption?
Answer:
The need for a secure method to distribute the shared secret key.
The primary challenge with symmetric encryption is key distribution. If you want to communicate securely with someone, you first need a secure way to give them the shared secret key. If an attacker intercepts the key during this exchange, all future communication is compromised.
99
Why is MFA significantly more secure than just a password?
Answer:
Because even if an attacker steals your password, they still cannot access your account without the second factor.
MFA's strength lies in its layered approach. A compromised password alone is no longer enough to grant access. The attacker would also need to steal your physical phone, trick you into giving them a code, or bypass your biometrics, which is a much harder task.
100
How does an Intrusion Prevention System (IPS) differ from an Intrusion Detection System (IDS)?
Answer:
An IPS is placed "in-line" with traffic and can actively block or prevent detected intrusions, whereas an IDS is a passive monitoring tool.
The key difference is that an IPS is an active, "in-line" device. It sits directly in the path of the network traffic and can take immediate action to stop a detected threat, such as dropping the malicious packets or blocking the source IP address. An IDS, in contrast, only detects and alerts.