Principles of Security

May 18, 2025

CIA Triad

  1. Confidentiality: the data is altered by authorized people only
  2. Integrity: the data isn’t altered
  3. Availability: the data is available

Principles of Privileges

The level of access is divided into to factors

  1. The individual’s role/function within the organisation
  2. the sensitivity of the information being stored on the system

Privileged Identity Management PIM : translate a user’s role within an organisation into an access role on a system

Privileged Access Management PAM: the management of the privileges a system’s access role has, amongst other things


The Bell-La Padula Model

AdvantagesDisadvantages
Policies in this model can be replicated to real-life organisations hierarchies (and vice versa)Even though a user may not have access to an object, they will know about its existence – so it’s not confidential in that aspect.
Simple to implement and understand, and has been proven to be successful.The model relies on a large amount of trust within the organisation.

members must go through vetting process


Biba Model

AdvantagesDisadvantages
This model is simple to implement.There will be many levels of access and objects. Things can be easily overlooked when applying security controls.
Resolves the limitations of the Bell-La Padula model by addressing both confidentiality and data integrity.Often results in delays within a business. For example, a doctor would not be able to read the notes made by a nurse in a hospital with this model.

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