Authentication vs Authorization: Zero trust in the age of non human identities

The rise of cloud computing, microservices, and automation has fundamentally altered the cybersecurity equation as we know it. non human identities (NHIs) now vastly outnumber human users and have consequently created a paradigm shift in how we approach access control. And this new reality demands we rethink our authentication and authorization strategies.

What is authentication?

Authentication is a gatekeeper of sorts, a methodology responsible for conducting the definitive identification of entities — a given prerequisite for granting access to requested resources. Over the years we saw authentication methods for human users evolve significantly. Passwords, while still widely used, are often supplemented with more robust techniques like multi-factor authentication (MFA) and biometrics. Single sign-on (SSO) has streamlined the process, allowing users to access multiple systems with a single set of credentials. However, now a new challenge has emerged: the rapid increment of identity types, and consequently their overall volume.

Modern hybrid workforces have become a melting pot of a variety of entities, many of which don’t fit neatly into traditional identity systems, including contingent workers, consultants, suppliers, and partners, as well as non human identities such as service accounts, bots, and devices. While the presently evolved state of authenticating human users remains functional, the expanding ecosystem of non human identities has made authentication management a bit more nuanced, and to be fair, many organizations at this point are at the risk of a non human identity attack. Yet, we may have a way forward:

Certificate-based authentication

Digital certificates serve as electronic passports for machines and provide quite a robust method of authentication. X.509 certificates, issued by trusted certificate authorities, contain information about the identity of the machine and its public key — a particularly effective method for authenticating servers, IoT devices, and applications.

But while certificate-based authentication offers strong security, it comes with a few challenges — managing the lifecycle of certificates, including issuance, renewal, and revocation, can be complex, especially in large-scale environments. Plus, automated NHI management tools often become necessary to prevent expiration-related outages.

API keys and tokens

API keys and tokens, like JSON Web Tokens (JWTs), are widely used unique identifiers that enable secure, automated authentication and information exchange between services in microservices architectures.

It’s worth noting that these tokens require careful management and essentially mandate the implementation of regular key rotation and revocation mechanisms. Short-lived tokens can help mitigate the risk of compromised credentials, and so using just-in-time privileged access credentials would be the way to go.

OAuth 2.0 for service accounts

OAuth 2.0, while often associated with user authentication, can be adapted for service accounts. This protocol allows applications to obtain limited access to user accounts on an HTTP service, making it suitable for authenticating non human entities in cloud environments.

What is authorization?

Surely, authentication advancements have bolstered security for human users, fixing problems of guessability and password weakness, but we seem to have fallen short when securing non human identities. And this is compounded by the fact that many organizations lack the tools to manage detailed permissions for NHIs and give too much access to “trusted” users or systems, leaving them highly vulnerable. To wit, the frontier now lies in authorization.

Authorization is a crucial component of the zero-trust model that often gets conflated with authentication. It is the process of permitting users to access specific resources such as documents, databases, applications, etc and only comes after authentication. Say, a new appointee in an organization may have been authenticated to visit an internal website of their company, but they may not see the same content or have access to all the features that the other users with higher privileges have. Why? Because they are not authorized.

In the same vein, authorization for non human identities determines what actions a machine, service, or application can perform after authentication. The enterprise policies dictate specific permissions for various resources, adapting to the dynamic nature of modern cloud and containerized setups. But by all means, authorization is what allows us to enforce ‘least privilege’ throughout an organization for all its entities, ensuring each one of them has only the permissions necessary for its function.

Types and methods of authorization

Organizations employ various authorization strategies to manage access control effectively. Here’s an overview of the primary methods:

• Discretionary Access Control (DAC): This model allows resource owners to choose who accesses their resources based on the requester’s credentials and rights.
• Mandatory Access Control (MAC): In contrast to DAC, MAC relies on a central authority to assign access rights based on predefined clearance levels and NHI classifications.
• Role-Based Access Control (RBAC): RBAC simplifies access management by granting permissions to roles rather than individual users. Users or non human identities are then assigned to these roles based on their functions or requirements.
• Attribute-Based Access Control (ABAC): This user authorization approach offers flexibility by using policies to decide access privileges based on various characteristics. These can include entity attributes (like department or role), resource attributes (such as data sensitivity), and contextual attributes (like time or location).
• Policy-Based Access Control (PBAC): PBAC user authorization combines business roles with dynamic policies, allowing for adaptable entitlements based on multiple parameters and changing requirements.

Challenges in authorization

While authorization is critical for securing access to resources, its implementation often presents significant challenges:

• Granular Access Control: Many organizations struggle to manage permissions at a sufficiently detailed level, particularly for non human identities and broad authorization policies can expose systems to security risks.
• Least Privilege Principle: Maintaining the principle of least privilege becomes complex in dynamic environments where roles and requirements frequently change — a challenge that gets far bigger when managing permissions for automated processes and non human identities.
• Identity Lifecycle Management: Efficiently managing permissions throughout the lifecycle of non human identities requires dynamic systems capable of automatically updating access rights as roles or functions evolve.
• Compliance and Governance: Adherence to external regulations is challenging, especially when dealing with diverse identity types. A minor misconfiguration, and you’re in breach.

Authentication vs Authorization

Comparing authentication vs authorization, both are 2 sides of the same coin which is zero trust access control. Here are the key differences that together make Identity Access Management (IAM) whole:

Factor	User authentication	User authorization
Core function	Authentication ensures secure access by confirming the identity of users or systems, usually through login details.	Authorization, in contrast, determines the permissions and access rights of an authenticated entity within a system. It controls what resources can be accessed and what actions can be performed.
Process sequence	Authentication is always the first step in the access control process and it must be completed successfully before any authorization checks are performed.	Authorization decisions can only be made accurately once an entity’s identity is confirmed.
Implementation	Authentication often employs cryptographic protocols and may involve multiple factors such as knowledge factors (passwords), possession factors (security tokens), or inherence factors (biometrics).	Authorization is typically implemented through access control models like Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), or Policy-Based Access Control (PBAC). These models define rules and policies that map authenticated identities to specific permissions.
Data handling	Authentication processes primarily deal with credentials and identity data. This information is usually stored securely, often using hashing or encryption techniques.	Authorization, on the other hand, works with access control lists, role definitions, and permission sets. All the related information is stored in databases or directory services and is used to make real-time access decisions.
Scalability and management	Authentication systems often require centralized management for consistency across an organization, particularly in enterprise environments using Single Sign-On (SSO) or federated identity solutions.	Authorization tends to be more distributed and granular, allowing for fine-tuned access control that can vary significantly between different systems or resources within the same organization. This granularity often requires more complex non human identity management and auditing processes.

Despite authn vs authz differences, user authentication and authorization are reliable methods of access control in IT environments, and a common challenge haunts both of them — the unprecedented rise in NHI management. Entro provides a comprehensive solution for managing and securing these identities and their associated secrets. It offers complete visibility into non human identities, enables the implementation of robust authentication and authorization controls, monitors for suspicious activities, and helps expedite the remediation of identified security risks. And the best part? You can plug it in with your existing secrets vault without a fuss. Click here to experience it yourself