PV080 Revision

1. You send 3 messages but the person observing the network cannot find out they were sent by the same person. It is:

• anonymity

• pseudonymity

• unlinkability

• unobservability

2. Which of the following are valid reasons for collecting personal data according to GDPR?

• The vital interest of the individual

• Marketing and personalized services

• Consent of the individual

• Public interest

3. Which of the statements about Vernam cipher are true?

• It is a symmetric cipher

• It enables us to reach perfect security

• It is a block cipher

• Same key can be reused without consequences

4. Which AES mode is the least secure?

• ECB

• CBC

• CTR

• all have similar security

5. Which of the statements are correct?

• Asymmetric cryptography is faster than symmetric

• Asymmetric cryptography requires longer keys

• Hybrid cryptography combines both symmetric and asymmetric approaches.

• Asymmetric cryptography can provide non-repudiation of sending.

6. Which of the following mechanisms are based on symmetric cryptography?

• MAC

• HMAC

• digital signature

• hash function

7. Which of the following features are typically not parts of the public key certificate?

• issuer (CA) and its signature

• private key

• validity period

• public key

8. Alice's company created a new secret cipher and uses it for encryption of all their communication. The approach:

• is generally OK as secret algorithms are safer than secret keys

• certainly provides authentication and integrity check

• is not good as you should not design your own cryptography

• goes against Kerckhoff's Principle

9. Which of the following authentication methods belong to authentication using sth you have?

• mobile phone

• fingerprint

• password

• voice

10. Time variant parameters in cryptographic protocols:

• always provide information about the exact time of sending the message

• should prevent man-in-the-middle attack

• provide protocol message freshness

• can be used in challenge-response protocols