Access Control - Introduction to Database Security - Lecture Slides, Slides of Network security

Download Access Control - Introduction to Database Security - Lecture Slides and more Slides Network security in PDF only on Docsity!

Access Control

Access Control

• Access control principles
• Mandatory Access Control (MAC)
• Discretionary Access Control (DAC)
• Role-based Access Control
• Matrix model

Access Control Example

Administrator^ Security

User

AuthenticationDatabase Authentication Barrier Access Control Barrier ReferenceMonitor

Objects

Auditing

Access Control Example

File 1 File 2 File 3 File 4 (^) Account 1 Account 2

John

Own R, W

Own R, W

Inquiry Credit

Alice (^) R

Own R, W W R

Inquiry Debit

Inquiry Credit

Bob (^) R, W R

Own R, W

Inquiry Debit

Mandatory Access Control

• Why MAC is needed?
  • Enhances security of database
  • Gives consistent view of operations
• General rule is all allowed accesses are provided by MAC
• Access that is not part of MAC is discretionary
• MAC adds to complexity

Mandatory Access Control

• MAC is used for type enforcement (TE) as is done in programming languages
• MAC protects organizational data
• MAC deals with database queries, reports and statistical studies
• Data protection for a class is determined by its label
• Relabel privileges follow a set of rules since label makes a difference in access

Mandatory Access Control

• Examples:
  • Official reports (DAC permission allows DAC copy)
  • Statistical analysis of medical records (providers and researchers have different view of same data)
  • Accounting records (updated by structured programs and accessed by unstructured programs)

Discretionary Access Control

• DACs provide flexibility in allowing access to database
• DACs protect unstructured work in progress
• DAC objects contain information protected by MAC
• DAC also includes privileges associated with email
• DAC labels are derived from MAC labels

Role-based Access Control

• Reference: “Role-based Access Control Models” by R. S. Sandhu et al, IEEE Computer, Vol. 29, Feb. 1996, 38-47.
• Databases are used by multiple users for multiple applications
• Role-based access control (RBAC) is one way to handle security for the users and applications

Role-based Access Control

• Role of the user in the organization determines the access level for the database
• DBAs create roles and assign permissions to roles
• DBAs and others can place users in appropriate roles
• Roles can define specific individuals allowed access or extent of access to resources for multiple individuals

Role-based Access Control

• RBAC is policy-neutral
• RBAC supports the following security principles : - Least privilege (only the needed permissions are assigned to roles) - Separation of duties (use of mutually exclusive roles – e.g., accountant writes check and manger signs the check) - Data Abstraction (instead of read/write/execute permissions such as credit/debit are established)

Role-based Access Control

• RBAC is independent of MAC and DAC
• RBAC can support MAC and DAC separately

RBAC Example

RBAC

Users Hierarchy Roles

RBAC Example

• RBAC0 denotes the minimum requirements for an RBAC system
• RBAC1 adds role hierarchies and includes RBAC
• RBAC2 adds constraints and includes RBAC
• RBAC3 includes RBAC1 and RBAC2 and transitively RBAC