What Is Certificate-Based Authentication?

As cyber threats grow, secure systems and data authentication have become far more important than they were thought to be. Certificate-based authentication (CBA) helps ensure secure access by using digital certificates instead of vulnerable passwords. Aside from security, CBA simplifies user access and protects data.

In this article, we will review CBA’s fundamentals, setup, and benefits for modern IT environments.

Understanding Certificate-Based Authentication

Certificate-based authentication is a method of authentication. It relies on validating users via digital certificates, like the X.509 certificate. This reduces password use and helps ensure phishing-resistant and secure authentication.

CBA forms a very important aspect of the contemporary IT setup. It enables seamless single sign-on (SSO) integrations, enhances security by shifting toward cryptographic keys instead of easily compromised credentials, and lets IT teams ensure that only authenticated users and devices can access sensitive resources. This consolidates their utilities within the organization’s security framework.

The Mechanics of Certificate-Based Authentication

CBA uses a secure framework. It authenticates identities with digital certificates, not passwords. The main components of CBA are digital certificates, public key infrastructure (PKI), and authentication servers. They work together to grant access to only trusted users and devices. This creates a multilayered system that dramatically improves security.

Key Components

CBA relies on the following core elements that work together to verify identities securely:

Digital Certificates

Digital certificates are the electronic versions of credentials that attest to the identity of users or devices. A trusted certificate authority (CA) issues such certificates. Each contains the holder’s identity, a unique public key, and an end date.

A series of certificate formats ensures tamper resistance. The two main kinds of CBA certificates are:

• Client certificates – These certificates authenticate users or devices to enable an organization to verify each entity accessing its network.
• Server certificates – These secure communication between servers. They authenticate the server’s identity to clients and ensure that both parties are trusted.

Public Key Infrastructure

PKI forms the backbone of managing digital certificates. It handles the issuance, verification, and revocation of certificates in the network.

The key elements include:

• Certificate authority – The certificate authority issues and signs digital certificates. Certificates are not considered trusted until signed by the certificate authority, which signifies that the identity has been verified through a proper process.
• Registration authority – The registration authority helps the certificate authority check the identity of requesting entities before the issuance of a certificate.
• Certificate Revocation List (CRL) and Online Certificate Status Protocol (OCSP) – The CRL lists the revoked certificate(s); the OCSP enables real-time status checks of a certificate to identify if it is valid, thus enabling the immediate access revocation by the administrator.

Public and Private Keys

CBA utilizes pairs of cryptographic keys:

• Public key – As its name suggests, the public key is public and used for data encryption or signature verification.
• Private key – Kept in secrecy by the owner of the certificate, private keys are used to decrypt data or generate a signature, which assures both authenticity and integrity. These keys allow for the security of communication and verification of users.

Authentication Server

Authentication servers verify the certificates and grant access based on their validity. Located at the center of various systems, including domain controllers and RADIUS servers, these are highly critical servers for granting access, enabling IT administrators to manage and keep track of the permissions throughout the network.

JumpCloud’s simplified Cloud RADIUS solution gives you all the benefits of RADIUS with none of the traditional hassle.

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Certificate-Based Authentication Flow

Certificate-based authentication (CBA) involves a series of steps that ensure only trusted users and devices gain access to network resources.

Here’s a quick look at the CBA process:

• Step 1: Certificate Enrollment and Issuance. A user or device requests a digital certificate from a trusted certificate authority (CA). Upon verification, the CA grants a certificate that identifies the authorized user’s or device’s identity.
• Step 2: Authentication Request. The user’s or device’s digital certificate is presented to the authentication server as the user attempts to use a certain secure resource.
• Step 3: Certificate Validation. The authentication server validates the certificate as genuine by determining certificate authenticity with the use of PKI. In some cases, a CRL or OCSP may be referred to.
• Step 4: User Authentication. The server verifies identity using a generally known process of digital signature checks. Precautions will be taken to ensure that the subject of the given certificate is the identity of the certificate.
• Step 5: Authorization and Access. If a user or device is authorized for successful authentication, then the server allows access to resources on the network.

Benefits of Certificate-Based Authentication

Certificate-based authentication (CBA) uses digital certificates and cryptographic keys to further enhance security with a strong alternative to passwords, which are immune to phishing. Tightly integrated with SSO, this lets users log in effortlessly across applications. For IT, automated certificate management via PKI makes access control easier, locking in compliance and secure, efficient identity verification.

Advantages in Security Compared to Conventional Methods

CBA permits some strong security features, which include EAP-TLS and RADIUS. 

These integrate to provide full encryption and safe access to remote WAN and Wi-Fi connections. EAP-TLS has been viewed as one of the most popular standards for secure wireless networks since it combines CBA with TLS to provide user-device authentication over encrypted channels. 

Meanwhile, CBA enforces strict access control policies used with RADIUS servers, adding a layer where organizations can manage user identities and access privileges centrally. This integration also contributes to Zero Trust because each network access attempt should be validated for the utmost safety, so it limits exposure to unauthorized users and contributes to preventing lateral movement in case of a breach. 

Certificate/key pair management through services like JumpCloud makes deploying the above protocols painless and less administratively burdensome while supporting compliance with industry regulations. Overall, this multilayered approach provides security with flexibility, helping small- to medium-sized enterprises (SMEs) achieve a scalable and resilient network authentication system.

Integration with Multi-Factor Authentication

Integrating CBA with multi-factor authentication (MFA) significantly improves security by adding an extra verification step. 

The provided solutions include both a certificate and other authentication factors, such as biometric scanning or entering a code. Particularly, this multimodal authentication makes unauthorized access almost impossible. The idea of multilayer security corresponds to Zero Trust principles, meaning each access point should be dually secured.

This means that for the environments that use RADIUS, MFA integration via RADIUS-as-a-Service will further drive Wi-Fi and remote access security.

Key pair management tools will provide admins with an efficient way to manage certificates, enabling seamless, scalable access across distributed networks. In this case, it provides a strong basis for security to ensure SMEs can deliver dependable, high-security access to critical resources while maintaining effective identity verification.

Certificate-Based Authentication Best Practices

To install CBA, follow these best practices:

Policy Creation and Enforcement

Effective CBA requires the establishment and enforcement of well-defined policies about certificate issuance, renewal, and revocation. Clearly define who can request a certificate, what the validation steps will entail, and how the renewal or revocation of a certificate should be handled. This stringent enforcement of policy in place helps to keep access controlled and cut security risks.

Revocation and Expiration Management

Certificate revocation and expiration are tracked to ensure a secure authentication system. Real-time validation may be allowed using the Online Certificate Status Protocol tool or Certificate Revocation List; once there are compromised or expired certificates, these will instantly be disabled.

It is very advisable to regularly audit expired certificates to efficiently clear them out so that only valid credentials provide access. In such organizations where RADIUS is in place, solutions like RADIUS configuration and authentication support a centralized way to manage network access points more securely and in a controlled manner.

Key Protection

Private key protection is critical to maintaining secure CBA services. Private keys should be safely stored on hardware tokens, smart cards, or a TPM module from unauthorized access. HSM allows tamper-resistant storage of keys, and proper rotation, revocation, and secure disposal keep them safe.

Users should be sensitized to the risks involved with phishing attacks and device theft and should be aware of the importance of performing regular encrypted backups. Advanced protection methods involve key splitting, multiparty computation, and biometric authentication. Continuous monitoring with a good incident response strategy ensures immediate action in case of a breach.

MFA Enforcement

MFA integration enhances CBA by adding an extra layer to the formal certificate with verification steps such as biometrics or one-time passwords. This addition makes a combination that ensures that even in a certificate compromise, unauthorized access to the system and data is impeded by a second factor to secure such against phishing, man-in-the-middle, and credential stuffing-type attacks.

Besides that, MFA minimizes credential theft risks, cushions the process of a weak password getting cracked, and ensures access to cleared users within an organization. This is the layered approach needed to protect against the complex threats in today’s landscape.

Secure Your Organization with JumpCloud

JumpCloud is an open directory platform that uses CBA, along with SSO, MFA, and several other methods for securing secure authentication, as part of its Zero Trust security approach to managing your IT environment. JumpCloud allows you to manage identities, devices, access, and SaaS all in one platform, providing both you and your users a seamless and secure experience.

To learn how JumpCloud can help you holistically secure your environment, try JumpCloud Free today.