Discuss different security models in details.

Bell -LaPadula Model (BLP):

a. Purpose:

• Used in government and military settings for access control.

b. Description:

• Formal rules for security using labels on objects and clearances for users.
• Labels range from most sensitive to least sensitive.

c. Key Point:

• No clear distinction between protection and security.

Biba Model:

a. Purpose:

• Ensures data integrity in computer systems.

b. Description:

• Groups data and users into ordered integrity levels.
• Users can’t corrupt data at higher levels or be corrupted by lower-level data.

c. Key Point:

• Focuses on preventing data corruption, in contrast to the Bell-LaPadula model.

Brewer and Nash Model (Chinese Wall Model):

a. Purpose:

• Dynamic information security controls to prevent conflicts of interest.

b. Description:

• Designed for commercial organizations to handle conflicts of interest.
• Information flow controls prevent conflicts.

c. Key Point:

• Commonly used in consulting and accounting firms.
• Aims to avoid situations where information flow could lead to a conflict of interest.