Eksamen 2015 Flashcards
1a) What is the definition (approximately of Information security according to ISO27001?
(i) confidentiality, (ii) integrity, (iii) availability, (iv) other security
properties, expressed in def. approximately as: ”The preservation of confidentiality,
integrity and availability of information; in addition, other properties such as
authenticity, accountability, non-repudiation and reliability can also be involved.”
1b) What is the definition (approximately) of confidentiality according to ISO27001?
Confidentiality is the property that information is not made
available or disclosed to unauthorized individuals, entities, or processes.
Subtract 1p in case of missing therm (un)authorized.
1c) What does “Give the interpretation of authorization consistent with the definition of confidentiality” mean?
Meaningful authorization is “to specify AC policy (i.e. access privileges)
1d) What does “Give the other (inconsistent) interpretation of authorization often found in text books.” mean?
Inconsistent authorization is that “the system grants the user access
1e) Mention the 3 main categories of security controls, with one example from each
i) Physical Controls, ii) Technical Controls and iii) Admin. Controls
1f) In which aspect is non-repudiation of data origin stronger than data authentication ?
Non-repudiation can provide proof of data authenticity to third parties. Data
authentication can only prove authenticity to intended recipient of data.
2a) Mention two situations when increased support to a staff member and special monitoring of
her/his integrity could be appropriate in order to reduce the risk of insider threats.
i) For staff who are working in highly trusted/sensitive positions.
ii) For staff in a difficult personal situation such as conflict, personal problems, job loss.
2b) Which type of vulnerability is exploited by social engineering attacks?
Social engineering attacks exploit vulnerabilities in humans, such as human
ignorance, gullibility and lack of awareness.
2c) Awareness can be seen as an intrusion detection function for stopping social engineering
attacks. Unfortunately people can make errors of judgment when trying to detect attacks.
In this scenario, what would be: i) a false positive, and ii) a false negative detection?
i) False positive is when staff misjudges a genuine colleague to be an attacker.
ii) False negative is when staff misjudges an attacker to be a colleague.
2d) Explain the consequence on i) the false-positive rate, and ii) the false-negative rate in case a
company implements a practice aimed at stopping all social engineering attacks.
i) It would give a relatively high false positive rate,
ii) It would give relatively low false negative rate.
2e) The terms private key and firewall represent security metaphors. Explain why they can be
bad metaphors that can cause misunderstanding of the security concepts they represent.
i) Private key can be misunderstood as giving privacy. In reality it decrypts
private (confidential) data, or it provides integrity protection for public data.
ii) Firewall can be misunderstood as an impenetrable barrier (analogous to
physical firewall) that stops all (malicious) traffic. In reality it is a security filter where
the achieved security (i.e. percentage of blocked attacks) depends on filtering rules.
3b) Mention the 2 factors that determine the strength of a threat agent (attacker).
i) Capacity, i.e. skills and resources to attack
ii) Motivation to attack
3c) Mention 2 typical approaches to identify relevant threat scenarios.
i) Attacker-Centric threat identification,
and
ii) System-Centric (aka. SW, design or architecture centric) threat identification, a
or
iii) Asset-Centric threat identification.
3d) Assume that a relevant threat scenario has been identified. Briefly describe the 2 main factors
that influence the likelihood of the threat scenario to happen.
i) The attacker (threat agent) strength.
ii) The degree of vulnerability (ease of compromise) of the targeted/involved
components (technical or human) in the threat scenario.
3e) Assume a quantitative risk model, where for a particular risk the following values are set:
AV (Asset Value) = EUR 800,000,
EF (Exposure Factor) = 0.2,
ARO (Annualised Rate of Occurrence) = 0.5.
Give the SLE (Single Loss Expectancy) and the ALE (Annualised Loss Expectancy).
i) SLE = EUR 160,000
ii) ALE = EUR 80,000
4a) Briefly describe 2 typical approaches for strengthening computer platform security.
i) Strengthening the OS, ii) Improved CPU security features, iii)
Platform virtualization, iv) Trusted Computing (integrated security hardware(TPM)
v) External security hardware combined with platform
4b) What does the acronym TPM stand for ?
Trusted Platform Module
4c) Briefly explain the 3 main TPM-supported services.
i) Authenticated boot: Report the integrity status of the software when booting.
ii) Sealed storage: Decryption with secret keys only ico. correct integrity.
iii) Remote Attestation: Report to external party the integrity status of software.
