IT-Security (Chapter 1)

Question 1

Examples of Cyber-Physical Systems

Answer 1

Industrial Facilites
Smart Grid
Smart Transport
Smart Cities

Question 2

Security vs. Safety

Answer 2

Security: Protection against intentional malice
Safety: Protection against accidental threats

Question 3

Defintion of “Threat”

Answer 3

A threatin an IT-based system is any possible event or sequence of actions that might lead to a violation of one or more security goals

Question 4

What is the Security Goal Acronym

Answer 4

CIAAC

Question 5

Security Goal 1

Answer 5

Confidentiality:

Data transmitted/stored should only be revealed to intended audience

Confidentiality of entitiesis also referred to as anonymity

Question 6

Security Goal 2

Answer 6

Integrity:

It should be possible to detect any modification of data

This requires to be able to identifythe creator of some data

Question 7

Security Goal 3

Answer 7

Availability:

Services should be available and function correctly

Question 8

Security Goal 4

Answer 8

Accountability:

It should be possible to identify the entity responsible for any communication event

Question 9

Security Goal 5

Answer 9

Controlled Access:

Only authorized entities should be able to access certain services or information

Question 10

Masquerade (Threats Technically Defined)

Answer 10

An entity claims to be another entity

Question 11

Eavesdropping (Threats Technically Defined)

Answer 11

An entity reads information it is not intended to read

Question 12

Authorization Violation (Threats Technically Defined)

Answer 12

An entity uses a service or resources it is not intended to use

Question 13

Loss or Modification of (transmitted) information (Threats Technically Defined)

Answer 13

Data is being altered or destroyed

Question 14

Denial of Communication Acts (Repudiation) (Threats Technically Defined)

Answer 14

An entity falsely denies its participation in a communication act

Question 15

Forgery of information (Threats Technically Defined)

Answer 15

An entity creates new information in the name of another entity

Question 16

Sabotage (Threats Technically Defined)

Answer 16

Any action that aims to reduce the availability and / or correct functioning of services or systems

Question 17

Physical Security (Safeguards Against Security Threats)

Answer 17

Locks or other physical access control

Question 18

Personnel Security (Safeguards Against Security Threats)

Answer 18

Employee screening processes

Security training and awareness

Question 19

Administrative Security (Safeguards Against Security Threats)

Answer 19

Controlling import of foreign software

Question 20

Emanations Security (Safeguards Against Security Threats)

Answer 20

Radio Frequency and other electromagnetic emanations controls

Question 21

Media Security (Safeguards Against Security Threats)

Answer 21

Scanning media for viruses

Question 22

Lifecycle Controls (Safeguards Against Security Threats)

Answer 22

Trusted system design, implementation, evaluation and endorsement

Question 23

Computer Security (Safeguards Against Security Threats)

Answer 23

Protection of the computing devices itself

Question 24

Communications Security (Safeguards Against Security Threats)

Answer 24

Protection of information during transport from one system to another

Question 25

Security Services

Answer 25

Authentication
Integrity
Confidentiality
Access Control
Non Repudiation

Question 26

Authentication (Security Service)

Answer 26

The most fundamental security service which ensures, that an entity has in fact the identity it claims to have

Question 27

Integrity (Security Service)

Answer 27

In some kind, the “small brother” of the authentication service, as it ensures, that data created by specific entities may not be modified without detection

Question 28

Confidentiality (Security Service)

Answer 28

Most popular security service, ensuring the secrecy of protected data

Question 29

Access Control (Security Service)

Answer 29

Controls that each identity accesses only those services and information it is entitled to

Question 30

Non Repudiation (Security Service)

Answer 30

Protects against that entities participating in a communication exchange can later falsely deny that the exchange occurred

Question 31

Security Supporting Mechanisms

Answer 31

Key management: All aspects of the lifecycle of cryptographic keys

Event detection / security audit trail: Detection and recording of events that might be used in order to detect attacks

Intrusion detection: Analysis of recorded security data

Notarization: Registration of data by trusted third party that can confirm certain properties

Question 32

Types of cryptographic algorithms

Answer 32

Symmetric encryption algorithms: (DES, 3DES, AES, Twofish)
Asymmetric encryption algorithms: (RSA, ElGamal)
Hash functions: (MD5, SHA1, SHA2, SHA3)

Question 33

Symmetric vs. Asymmetric

Answer 33

Assymetric comes with high overhead
Symmetric allows higher data thoughput
Assymetric for encrypting symmetric

Question 34

Message Detection Codes (MDC)

Answer 34

Hash of data as fingerprint to check for modifications

Question 35

Message Authentication Codes (MAC)

Answer 35

Append a secret key 𝐾 to a message 𝑚 and hash it to ℎ(𝑚|𝐾)

Result is fingerprint of the message that cannot be forged as attackers do not know key K