Cybersecurity Principles & Protocols Flashcards

Alice wants to send Bob a message that only Bob can read using asymmetric cryptography. Which key should Alice use to encrypt it?

Answer: Bob's public key

Encrypting with the recipient's public key ensures only the matching private key holder can decrypt.

A digital signature on an email is created using which key?

Answer: The sender's private key

The sender signs a hash with their private key, and anyone can verify it with the sender's public key.

A security analyst compares a downloaded file's checksum with the vendor's published value. Which security goal is being verified?

Answer: Integrity

Matching hashes such as SHA-256 confirm the file was not altered, which verifies integrity.

Adding a unique random value to each password before hashing primarily protects against which attack?

Answer: Rainbow table attacks

A salt makes precomputed hash tables useless because identical passwords produce different hashes.

Which feature ensures that compromising a server's long-term private key does not expose previously recorded TLS sessions?

Answer: Perfect forward secrecy

Perfect forward secrecy uses ephemeral key exchanges such as ECDHE so each session key is independent of the long-term key.

Which algorithm is designed specifically to slow down brute-force attacks on stored passwords through key stretching?

Answer: bcrypt

bcrypt applies a configurable work factor to make each password guess computationally expensive.

A browser needs to check in real time whether a web server's certificate has been revoked. Which protocol does it use?

Answer: OCSP

The Online Certificate Status Protocol returns the revocation status of a single certificate on demand.