Understanding Computer and Information Security

• Computer security involves examining risks, understanding security goals, examining threats, and identifying controls.
• "Secure" means protecting valuable assets, including physical assets, money, and confidential data.
• Computer security is the protection of a company's assets by ensuring safe, uninterrupted system operation and safeguarding computers, programs, and data files
• Computer security protects information and physical assets of a computer system.
• It involves ensuring confidentiality, integrity, and availability of processed and stored information
• Measures include policies, procedures, hardware, and software tools which protect systems and information.
• Cybersecurity protects systems, networks, and digital data from cyber threats like hacking and malware.
• Information security (InfoSec) focuses on protecting both digital and physical data, ensuring confidentiality, integrity, and availability (CIA triad).
• Cybersecurity deals with digital threats, while information security covers all forms of data protection (including physical security).
• The internet hosts numerous threats, including viruses, worms, Trojan Horses, hacking, denial of service attacks, masquerading, spoofing, fraud, data theft, and malicious damage.

The need for security is paramount in areas like:

• Banking
• Education
• Government
• Healthcare
• Retail
• Telecommunications

Types of security

• Physical: Environmental protection.
• Logical/System/Technical: Authentication, secure communications.
• Procedural/Personnel: Security policy.

Principles and Concepts

• Security Requirements
• Security Threats/Attacks
• Security Controls

Core tenets of information security

• Confidentiality: Protecting data from unauthorized disclosure.
• Integrity: Ensuring data isn't altered or destroyed in an unauthorized manner.
• Availability: Ensuring continuous operation of computing systems so legitimate users can access data.

More concepts

• Authentication: Positive identification of person/system seeking access.
• Access Control: Limiting and controlling access to host systems.
• Non-repudiation: Guaranteeing data's origin and preventing sender/receiver from denying a transmitted message.

Threat and vulnerability

• Threats are circumstances that could cause loss or harm to a computing system.
• Vulnerabilities are weaknesses exploitable to cause loss or harm.
• Controls refers to protective measures.

Note:

• A threat is blocked by control of a vulnerability.

Threats can be accidental or deliberate:

• Physical: Fire, flood, power failure.
• Human: Operator errors, misuse of resources, hacking, viruses.
• Equipment: CPU, network, storage failure.
• Failure to preserve CIA can result in disclosure, denial, destruction, or modification of data, leading to consequences.

Consequences of security breaches include:

• Financial loss
• Embarrassment
• Breach of commercial confidentiality
• Breach of personal privacy
• Legal liability
• Disruption to activities
• Threats to personal safety

Security threats fall into four general categories

• Interruption: An asset is destroyed or unusable.
• Interception: An unauthorized party gains access to an asset.
• Modification: An unauthorized party gains access to and tampers with an asset.
• Fabrication: An unauthorized party inserts counterfeit objects into the system.

MOM

• Method refers to the skills, knowledge, tools to pull off an attack
• Opportunity refers to the time and access to accomplish an attack
• Motive refers to the reason to want to perform attack against system.

Vulnerabilities exist across hardware, software, and data components

• Hardware vulnerabilities include physical damage or traffic interception.
• Software vulnerabilities include malicious software changes, accidental modification, logic bombs, and unauthorized copying.
• Data vulnerabilities encompass wiretapping, planting bugs, monitoring electromagnetic radiation, bribery, theft, and modification.
• Security controls include legal restrictions, physical controls, encryption, plus software, and hardware controls.
• Security controls also encompass policies/procedures needed to preserve confidentiality, integrity and availability.

Computer criminals include:

• Amateurs: Normal people exploiting security weaknesses for cash or valuables.
• Crackers/hackers: Often students attempting to access unauthorized computing facilities.
• Career criminals: Those who understands the targets of computer crime.

Methods of Defense

• Prevent - by blocking the attack or closing the the vulnerability.
• Deter - by making the attack harder, but not impossible.
• Deflect - by making the other target more attractive (or this one less so).
• Detect - by either as it happens or some time after the fact.
• Recover from its effects.

Types of Controls

• Physical controls
• Encryption
• Software controls
• Hardware controls
• Policies and procedures

Effectiveness of Controls

• Awareness of problem
• Likelihood of use
• Overlapping controls
• Periodic review