Authentication is an essential mechanism in cybersecurity. It allows the verification of a user’s identity before granting access to a system, an application, or sensitive data.
With the increase in cyberattacks, organizations can no longer rely on a single method. Today, several authentication methods exist, each with its own advantages, limitations, and use cases.
This article presents the main authentication methods used in modern information systems.
1. Local Directories (On-Premises)
Principle
Local directories are installed and managed directly on the company’s internal infrastructure. They centralize user accounts, groups, and access rights for internal resources.
Focus: Active Directory (AD)
This is the most widely used solution in Windows environments. It serves as a central pillar for:
Centralized management of users and groups
Access control to internal resources (files, printers, servers)
Enforcement of security policies (GPOs) and workstation authentication
Advantages: Full control by the organization, deep integration with Windows environments, operates without cloud dependency.
Disadvantages: Complex administration, heavy maintenance and update requirements, less flexible for cloud services.
The Alternative: LDAP-Based Directories (e.g., OpenLDAP)
The LDAP protocol is a standard that enables access to directory services in heterogeneous environments.
Advantages: Open standard, highly flexible, and compatible with many systems (Linux/Unix).
Disadvantages: More technical configuration and less user-friendly for beginners.
2. Cloud Directories
Principle
Cloud directories are hosted by service providers and accessible via the Internet. They are designed to manage identities in modern, distributed environments.
Example: Entra ID (Azure AD)
Primarily used for SaaS applications, cloud services, and remote user authentication.
Advantages: High availability, perfectly suited for remote work, easy integration with cloud services.
Disadvantages: Dependence on the provider and Internet connectivity, less control than an on-premises directory.
3. Hybrid Directories
Principle
This approach combines an on-premises directory with a cloud directory. Identities are synchronized between both environments to ensure a gradual transition or to meet mixed requirements.
Advantages: Maximum flexibility, service continuity, well suited for large enterprises.
Disadvantages: Complex architecture to manage, risks in case of poor data synchronization.
(learn.microsoft.com)
(en.wikipedia.org)