D329 Networks and Security Applications - Set 2 - Part 2

Correct Answer: Encryption, integrity, and server authentication

Transport Layer Security encrypts data in transit, verifies integrity, and authenticates the server through its certificate, underpinning HTTPS.

Correct Answer: Binding a public key to a verified identity

A digital certificate binds a public key to an identity and is signed by a certificate authority, allowing relying parties to trust the key belongs to that entity.

Correct Answer: A trusted entity that issues and vouches for digital certificates

A certificate authority verifies identities and signs certificates. Clients trust certificates chaining to a CA already in their trust store.

Correct Answer: Encryption using the same key to encrypt and decrypt

Symmetric encryption uses one shared secret key for both operations. It is fast but requires securely distributing the key to all parties.

Correct Answer: Encryption using a mathematically related public and private key pair

Asymmetric encryption uses a public key for encryption and a corresponding private key for decryption, solving the key distribution problem at greater computational cost.

Correct Answer: Asymmetric securely exchanges a key, then fast symmetric encryption carries the data

Asymmetric cryptography securely establishes a shared session key despite being slow, after which efficient symmetric encryption protects the bulk of the traffic.

Correct Answer: It should be infeasible to find two inputs producing the same digest

Collision resistance means finding two inputs with the same hash should be computationally infeasible. Hashes must also be one-way and deterministic.

Correct Answer: Hashing is one-way and salting defeats precomputed rainbow tables

Encryption is reversible if the key leaks. Hashing is one-way, and a unique random salt per password prevents precomputed table attacks and identical hashes for identical passwords.

Correct Answer: Authenticity and integrity of a message, plus non-repudiation

A digital signature, created with the sender's private key, proves the message came from that sender and has not been altered, and the sender cannot credibly deny it.

Correct Answer: An attacker secretly relaying and possibly altering communication between two parties

In a man-in-the-middle attack the adversary positions between communicating parties, able to read and modify traffic while both believe they communicate directly.

Correct Answer: Certificate validation proves the server's identity before the session proceeds

The client verifies the server's certificate chains to a trusted CA and matches the hostname, so an interposed attacker cannot present a valid certificate.

Correct Answer: Overwhelming a system so legitimate users cannot access it

A denial-of-service attack exhausts bandwidth, connections, or processing capacity so that the service becomes unavailable to legitimate users.

Correct Answer: Traffic originates from many distributed sources simultaneously

Because DDoS traffic comes from thousands of distributed hosts, simple source blocking is ineffective and the aggregate volume can exceed available capacity.

Correct Answer: Deceptive messages tricking recipients into revealing credentials or running malware

Phishing uses fraudulent messages impersonating trusted parties to induce victims to disclose credentials or execute malicious attachments and links.

Correct Answer: A targeted phishing attack tailored to a specific individual or organization

Spear phishing researches its target and personalizes the message, making it far more convincing and successful than generic bulk phishing.

Correct Answer: User awareness training combined with multi-factor authentication

Training helps users recognize phishing, while MFA ensures that stolen passwords alone are insufficient for an attacker to gain access.

Correct Answer: Software intentionally designed to cause harm or gain unauthorized access

Malware is software created with malicious intent, encompassing viruses, worms, trojans, ransomware, spyware, and rootkits.

Correct Answer: A worm self-propagates without requiring a host file or user action

A worm spreads autonomously across networks by exploiting vulnerabilities, while a virus attaches to a host file and requires execution to spread.

Correct Answer: Malware disguised as legitimate software to induce installation

A trojan masquerades as useful software so users install it voluntarily, after which it performs malicious actions such as opening a backdoor.

Correct Answer: Maintain privileged access while concealing its presence

A rootkit hides malicious activity by subverting the operating system, making detection difficult while preserving privileged access for the attacker.