Application Security Models

I like to start system design (at the application level) with the security model that will be used to protect the system. Application security models have several attributes that need to be addressed at each layer of the application.

In an earlier blog post, I introduced the attributes of an application security model:

• User Management
• Authentication
• Authorization
• Confidentiality
• Integrity
• Non-Repudiation
• Availability
• Auditability
• Identity Propagation

As I finish blog posts on the remaining items, I will update this post with links.

We can briefly define each of these attributes as:

User Management: The creation, deletion, and modification of users, groups, and roles within an identity system support an application or group of applications. The modifications can include adding or removing attributes, changing passwords, resetting passwords, locking user accounts, adding or deleting group membership, or similar activities.

Authentication: The process of proving your identity to the system.

Authorization: The process of determining if the authenticated identity is allowed to access the requested server resource based upon a predefined authorization policy.

Confidentiality: Limiting access to the data to parties that should be allowed to see it in transit or at rest.

Integrity: Ensure that the message was not modified in transit between two actors.

Non-Repudiation: Assurance that the actor who sent the message cannot deny that it sent the message. This attribute of a message often includes integrity of the message as well. Meaning, the actor who sent the message cannot deny that it sent the message in the form that was received.

Availability: Measure of the system performing as required.

Auditability: Ability of an Information Security Auditor to have sufficient information after the fact to reproduce an event of interest and confirm that appropriate security policies are in place regarding all aspects of the system (for application users and administrative users

Identity Propagation: A mechanism that, ideally, securely transmits an authenticated identity from one system actor to another (think SAML 2.0 Bearer Tokens or JWT tokens).

Image: Patterned / Bojan Bjelic