Cyber-Security

Acceptable risk for the severity of all consequences of an attack originatign from computers as the target or enabler

Three goals of cyber security:

• Confidentiality

  • Protection against unauthorized access

  • Encryption, Access Control

• Integrity

  • Protection of accuracy, consistency and trustworthiness

  • Signing, hashing, validation, version control

• Availability

  • Ensuring timely and reliable access

  • Load balancing, Backups, Redundancy

Individual, group, organization or government that conducts or has the intent to conduct detrimental activities.

Any kind of malicious activity that attempts to collect, disrupt, deny, degrade or destroy information or system ressources

A tool or method designed to reduce or stop harmful actions or threats

• Partitioning

• Security domains

• Access and User control

• Development assurance

• Cryptography

• Continued assessment and update

The chance of harm or loss from a pontential problem, based on Severity and likelihood

Important element or ressource in a system

• Data

• Software/Hardware

• Personell

Potential danger or possible harmful event

• Phishing

• Malware

• Spam

• Insiders

• Botnet

Sources:

• Nation states

• Terrorists

• Criminals

• Insiders

Weakness in a system, security procedures, controls or implementation, that could be exploited by adversary

Structured approach to judge cyber security of a system.

• Identify assets

• Enumerate threat scenarios

• Determine impact and likelihood

• Quantify and judge risk

• Countermeasures

Active

• alter

• destroy

• compromise

Passive

• eavesdropping

• monitoring

Design principles that inherently boost security

• Defense in depth (independence, layering)

• Integrity of software updates

• Continued airworthiness

• Simplicity

• Detection and restoration

• Minimize external interfaces

• Disable all unused interfaces

• Error handling

• Least priviledge

• Controlled access

• Network (Ports, Protocols)

• Application (User input, APIs)

• Physical (Buildings, server rooms, devices)

• Human (Phishing)

• IoT and embedded systems (Firmware, protocols)

• Cloud (Config, APIs)

Modeling and analyzing threat scenarios:

Enumeration of threats for analysis:

Diagram that depicts attacks with all neccessary or possible steps

Equivalent to fault tree

Tabularized diagramm mapping scenarios on a Likelihood-Severity grid.

Risk can be deducted

Encoding information such that it is not readable as is and is only readable by owners of a key or with great effort.

Symmetric:

• Encryption and decryption with the same shared key

• Encryption and decryption only by owners of key

Asymmetric:

• Encryption by everyone with public key

• Decryption only by owner of private key

Rivest-Shamir-Adleman (RSA)

• Public Key encryption based on Prime factorization

Data Encryption Standard (DES)

Advanced Encryption Standard (AES)

• Mapping of any input to a fixed length output

• Modification of input changes hash significantly

  —> Proof of tampering

• Non reversible

Use cases:

• Storing passwords

• Data integrity

• Signatures

• Mathematical attack

• Brute force

• Timing attack

• Chosen Cyphertext

• Sandboxing

• Firewalls and segmentation

• Intrusion detection

• Access Control

• Increased number of attacks

• More complex systems

• More integrated and connected systems

Conditions of the A/C which are not caused by errors or failures

Conditions that are a combination of independent failure conditions (dependent due to threat)

Combination of threat, attack and confition:

• Threat source

• Attack vector

• Attack path

• Possible mitigations

• Threat conditions as effect of the attack

• Deterrent

• Preventive

• Detective

• Corrective

• Restorative

Coordinated activities to:

• identify, analyze

• contain

• remediate

• recover

• learn

from incidents.

• Preparation (Training of Staff, implementing tools, backups)

• Identification

• Containment

• Eradication

• recovery

• Lessons Learned

• Ongoing improvement

• Vulnerability scanners

• Threat intelligence

• Intrusion detection

• Digital forensics

• Monitoring

• Predictive maintenance

• Vulnerabiliyt assessment

• Immutability and Data Integrity

• Digital identities

• The network is a dangerous environment all the time

• There are external and internal threats in the network

• The location of the network is not enough to ensure credibility

• All devices, users and traffic should be authenticated and authorized

• Security policies must be dynamic ad calculated based on as many data sources as possible