CISSP CBK (Common Body of Knowledge - Ortak Bilgi Bütünü)

1- Risk Definition

  • New Definition: Risk is now defined as an event that has a negative impact (e.g., data breach)
  • Old Definition: The likelihood of a negative event happening (still used in the workplace)
  • Hazard/Tehlike (New): A natural disaster (e.g., earthquake, tornado)

2- Risk Perspectives

  • Asset-Based (Varlık Bazlı): Focuses on what can happen to your assets.
  • Outcomes-Based (Sonuç Bazlı): Focuses on risks to desired outcomes (e.g., profit, sales).
  • Process-Based (Süreç Bazlı): Focuses on safety-related outcomes of process changes.
  • Threat-Based (Tehdit Bazlı): Focuses on threat actors who can exploit vulnerabilities.

3- Risk Choices

A new preliminary step has been added:

  1. Prioritize (Önceliklendirme): Prioritize risk based on their impact on human safety first.
  2. Decide what to do: Then choose one of the four options (Mitigate -azalt-, Accept, Transfer, Avoid)

4- SETA (Security, Education, Training, and Awareness)

  • The acronym is now SETA (formerly SATE).
  • Education: To increase knowledge and understanding.
  • Training: To improve skills and proficiency for specific tasks.
  • Awareness: How familiar someone is with security policies.2

5- Due Diligence & Due Care (Gerekli Özen & Gerekli Dikkat)

Due Diligence
  • The “legwork” or research. Performing SETA evaluations is an act of due diligence.
Due Care
  • The “action”. Providing the SETA program to employees is an act of due care.

6- NDAs (Non-Disclosure Agreements - Gizlilik Sözleşmeleri)

  • Also Known As (AKA):
    • Confidentiality Agreements (CAs) Gizlilik Sözleşmeleri
    • Confidential Disclosure Agreements (CDAs) Gizli Bilgi Açıklama Anlaşmaları
    • Proprietary Information Agreements (PIAs) Ticarî/Sahipli Bilgi Anlaşmaları
    • Secrecy Agreements (SAs) Sır Tutma Anlaşmaları

7- GDPR Privacy Tenets (GDPR Gizlilik İlkeleri)

  • Purpose limitation: Data collected only for a stated purpose
  • Data minimization: Data used only for a stated purpose.
    • Veriler yalnızca belirtilen amaç için kullanılır.
  • Accurary: Proving a method for correction.
  • Storage limitation: Don’t keep data longer than needed.
  • Integrity/Confidentiality (Bütünlük/Gizlilik): No unauthorized modifications or viewing.
  • Accountability: The ability to demonstrate compliance.

CIA Model

Confidentiality (Gizlilik)

  • Only those who are authorised have access to the data. Only the right people can see the information. It’s about privacy.
    • Data encryption
    • Access control using usernames and passwords
    • Identification (Tanımlama)
    • Authentication (Doğrulama)
    • Authorization (Yetkilendirme)

Integrity (Bütünlük)

  • There are no unauthorized modifications to the data or that there are authorized changed only the data. It’s about preventing information from being corrupted, altered, etc. by unathorized persons.
    • Digital signatures
    • Granting modification permissions only to spesific users
    • Using hashing algorithms to verify file integrity
    • Checksum

Availability (Erişilebilirlik)

  • Making the data accessiple to authorized entities. You can access your information when you need it.
    • Regular data backups
    • Using redundant hardware (e.g., backup servers) to prevent system failures
      • Redundancy (Yedeklilik): Systems that will be activated in the event of a disaster.
    • **Protecting against Denial-of-Service (DoS) attacks

Additional Functions

Authentication (Kimlik Doğrulama)

  • Making sure that the individual is who they say they are or the entity is who they say they are.
    • Example: Passwords, fingerprints, security keys.

Non-Repudiation (İnkâr Edilemezlik)

  • Provides proof of the origin of data and the integrity of a transaction. It prevents a person from later denying that they performed an action (e.g., sent a message or authorized a payment).
    • Example: Digital signatures, detailed log files that record who performed an action and when.