LDAP vs. Active Directory: What’s the Difference? – Rublon (2024)

Last updated on January 26th, 2023

LDAP and Active Directory are two common terms in Identity and Access Management (IAM). Some people use them interchangeably. Nevertheless, they are not the same thing. Whereas Active Directory is a directory server that stores user information such as usernames, phone numbers, and email addresses, LDAP is a protocol that allows reading and modifying that information. You can also use LDAP to authenticate users using the Bind operation. Although LDAP is the core protocol behind Active Directory, you can use LDAP to query any other directory database that supports it, e.g., OpenLDAP and FreeIPA. But what is LDAP vs. Active Directory, and how do they differ? Let’s dive in.

What is Active Directory?

Active Directory, AD for short, is a directory server developed by Microsoft that allows storing directory service information such as users and devices in a centralized and hierarchical database. AD comes with many services such as authentication, access policies, and group management.

Why Do Companies Need Active Directory?

IT environments can be very complicated. IT administrators want to simplify their job as much as possible so they do not waste time managing dozens of scattered user accounts. Users find it uncomfortable to have to provide a different set of credentials for every application they use.

Enter Active Directory, a single directory that stores all information about all users and devices in the organization in one place. AD makes user management a piece of cake for administrators and eliminates the need to provide a different set of credentials for each application for users. In a company with AD, when an administrator needs to change a user’s account, they only make that change in one place in Active Directory. Had the company not been using Active Directory, the administrator would have to make that change in every application separately. Active Directory saves time and workload.

Incidentally, the preceding benefits of using Active Directory apply to other directory servers, too. Such external identity providers allow administrators to manage identities in a centralized place and make changes across multiple applications and services from a single location.

What is the Structure of Active Directory?

The Active Directory structure consists of the following components:

• Users and Computers – Items represent a particular user account or computer in the company; each user account is described by its attributes, e.g., name, email address, location, etc.
• Organizational Units (OU) – Used to organize users, groups, computers, and other organizational units.
• Domains – Collection of users, groups, computers, OUs.
• Trees – One or more domains in a logical hierarchy that defines trust between domains, i.e., who can access what
• Forest – A top-tier in the hierarchy that contains a group of trees

What is LDAP?

Lightweight Directory Access Protocol (LDAP) is a protocol that applications can use to speak to directory services such as Active Directory. The LDAP protocol queries user information to read, modify or update it.

During user authentication, LDAP can bind to the directory service database, such as Active Directory. While advanced ways of authentication such as Kerberos token and client certificate are possible, the simplest authentication is simply checking the username and password the user entered into the application log-in form against the information stored in a directory server. If the entered information is correct, the user gets logged in. Otherwise, the user is denied access.

Sometimes people use the name LDAP when they mean an LDAP server. An LDAP server is any directory server that supports the LDAP protocol. Examples of LDAP servers include FreeIPA, OpenLDAP, Apache Directory Server, and Active Directory.

How Does LDAP Authentication Work?

LDAP authentication works based on a binding operation. The LDAP Bind operation initiates a session between the user and the server, during which an LDAP-enabled application sends the user’s credentials to a directory service like Active Directory to check if they are correct.

1. User enters credentials.
2. LDAP protocol sends credentials to the LDAP server
3. LDAP server checks the credentials against the database, decides whether the credentials are correct, and prepares the answer
4. LDAP protocol takes the LDAP server’s answer and sends it back to application
5. The application receives the answer and acts upon it, e.g., if the answer is yes, the application logs in the user; if no, the application prints “Username or password incorrect”

LDAP vs. Active Directory: What’s the Difference?

The main difference between Active Directory and LDAP is that Active Directory is a directory services database, while LDAP is a protocol that talks to it.

Refer to the following table for more LDAP vs. Active Directory differences.

Abbreviations like LDAP and AD might not tell you much about these technologies. However, full names already contain a hint. LDAP is an abbreviation of Lightweight Directory Access Protocol. The full name makes it clear that LDAP is a lightweight protocol you can use to access a directory. A directory like Active Directory. Both AD and LDAP have different functions. LDAP is a protocol. Active Directory is a directory server.

LDAP is a cross-platform open standard, but Active Directory is Microsoft’s proprietary software meant for Windows users and applications.

The primary use of LDAP is to query and modify directory servers. On the other hand, the primary usage of Active Directory is to store user information, provide authentication, and allow administrators to manage groups, users, and policies.

LDAP vs. Active Directory: Cyberattacks

Centralized access control comes with many benefits. Administrators can easily manage users and devices while users can use the same account on multiple applications and services. However, such a solution comes with a security concern. Should hackers compromise an account, they gain instant access to a user’s account on all applications and services. Worse still, hackers can take over the entire IT infrastructure if they compromise an administrator’s account. Active Directory administrator accounts are a prime target for hackers.

Password-based authentication is the most popular form of verifying user identity. Sadly, passwords are easily hackable, contributing to a heightened risk of hackers compromising your Active Directory infrastructure.

How Does MFA Protect Your Active Directory Users?

Thankfully, you can enhance the security of user logins by introducing an extra layer of protection. For example, require the user to accept a push notification on their phone after they entered a correct password. Such authentication is Multi-Factor Authentication (MFA) and is a vital part of modern identity management. The good thing about MFA is that it does not change your old authentication process. Instead, Multi-Factor Authentication adds another layer of security on top of passwords. In the first step of MFA, passwords are still checked against the LDAP server. Then, a security provider like Rublon demands the user to demonstrate the second authentication factor, such as accepting the Mobile Push authentication request sent to the user’s phone. Users can access their account only if they enter the correct password and complete the second authentication factor. Otherwise, the user is denied access. MFA stops hackers who managed to compromise the user’s password because these malicious actors usually do not have access to the user’s mobile device and cannot accept the push notification.

Conclusion

LDAP and Active Directory are often used in tandem. They share few commonalities and should not be treated as competitive solutions. Since Active Directory and other LDAP servers like OpenLDAP act as centralized identity providers, it is of utmost importance to protect them with comprehensive safeguards like Multi-Factor Authentication (MFA).

Rublon Multi-Factor Authentication (MFA) is a cutting-edge security solution that supports hundreds of applications, VPNs, and services.

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