Inferential Statistics Quiz

Inference in Census Data

• Inference occurs when applying statistics to census data from the Czech Republic, specifically when considering the average monthly income of programmers in a small village (100 citizens) between ages 60 and 70.

XOR Operation

• The XOR operation is commutative (A XOR B = B XOR A).
• It detects if the operands are different.
• It does not depend on the most significant bits of the operands.
• It cannot be viewed as bitwise multiplication modulo 2.

Man-in-the-Middle Attack

• A man-in-the-middle attack in the Diffie-Hellman protocol occurs when the attacker re-encrypts the communication of two parties.
• The attacker shares two different symmetric keys with parties.
• The attacker is able to communicate with each of the parties.
• The attacker performs the Diffie-Hellman protocol with each of the parties.

Risk Rating Matrix

• A level of risk of a given high probable threat can be low if the impact rating is very low.
• The level of risk depends on both the likelihood of a threat and the impact rating.
• The likelihood of a threat, as well as the cost of impact, is only estimated and not precisely computed.
• The matrix combines an impact rating and the probability that a threat occurs with successful exploitation.

MAC and Digital Signatures

• MAC requires a shared secret key, unlike a cryptographic hash function.
• Collision resistance is important for MAC, unlike for cryptographic hash functions.
• MAC is not a type of digital signature.
• HMAC is a standard that specifies the construction of MAC from cryptographic hash functions.

Pseudonymity

• Pseudonymity ensures that a user may use a resource or service through the TSF (Target of Evaluation Security Functions) not providing a capability to determine the original user identity based on a provided alias.

Software Security Rules of Thumb

• Do not implement cryptographic functions yourself even if the library you are using becomes unmaintained.
• View all user inputs as potentially harmful.
• Dedicate enough time to security education.

Active Network Monitoring

• It often inserts new traffic into the network.
• It is typically more powerful than passive network monitoring.
• It usually acquires the information from actively sent network probes (network packets).

Improving Password-Based Authentication

• Improve security by adding another factor (e.g., hardware token) to the authentication scheme.
• Use a strong unique password for each service.
• Increase the entropy/randomness of passwords.