What is a Private Certificate Authority?
Keytos Team |
- Updated: August 6, 2026What is a Private Certificate Authority?
A Private CA refers to a Certificate Authority (CA) that you run within your organization that only your organization trusts. This is different than a Public CA, which is a CA that is trusted by the public and is included in the trusted root store of operating systems and browsers. Private CAs are used to issue certificates for internal use, such as for internal websites, applications, user authentication, and device authentication. Check out our blog on Public vs Private CAs to learn more about what else separates these two certificate authorities.
How Can SSL Certificates Be Issued For Internal Websites and Applications?
For internet-facing websites, SSL certificates are typically issued by a public CA, which is trusted by the public and included in the trusted root store of operating systems and browsers. Most websites nowadays use ACME (Automatic Certificate Management Environment) to automatically issue and renew SSL certificates from public CAs like Let’s Encrypt. However, for internal websites and applications that are not accessible to the public or even to the internet, a private CA can be used to issue SSL certificates that are trusted within your organization.
Private CAs, like EZCA, can be used to issue SSL certificates for internal websites and applications, ensuring that the certificates are trusted by your organization’s devices and users. Unlike public CAs that require 47-day validity periods and are log all certificates to the Certificate Transparency (CT) logs, private CAs can issue certificates with longer validity periods and do not log certificates to CT logs. Private CAs also provide ACME support for automatic certificate issuance and renewal, with the added benefit of being able to run within your network so your internal websites and applications can be accessed without needing to be exposed to the public internet.
How Can Private CAs Be Used for Application, User, and Device Authentication?
Private CAs can be used to issue certificates for application, user, and device authentication. Examples include connecting your laptop to your corporate Wi-Fi, connecting to your VPN, or even authenticating to Entra ID using certificate-based authentication.
Unlike self-signed certificates, which are not trusted by default and require manual installation of the certificate on each device, private CAs provide a more scalable and manageable solution for authentication. Private CAs can issue certificates that are trusted by your organization’s devices and users, allowing for seamless authentication without the need for manual certificate installation.
How to Issue Smart Cards and Prove Identity with a Private CA
Unlike passwords, a Smart Card certificate cannot be leaked, stolen, or reused. Once the certificate’s private key is written to the Smart Card, it never leaves. From there it can be used for device PIV (Personal Identity Verification) login, or even Entra ID Certificate Based Authentication (CBA).
Private CAs like EZCA can be used to issue Smart Card certificates for your organization’s users, allowing for secure authentication and identity proofing. Smart Cards provide a higher level of security than traditional passwords, as they require physical possession of the card and a PIN to authenticate. This makes them an ideal solution for organizations that require strong authentication for their users.
How To Issue Certificates To Internal Devices With a Private CA
A primary application of private CAs involves issuing internal authentication certificates for users and devices, facilitating their authentication into Virtual Private Networks (VPNs) and Wi-Fi networks. Commonly, mobile device management (MDM) tools, like Intune, issue these certificates. Refer to our blog to explore deploying certificates via Intune SCEP.
How To Get Started With a Private PKI
Want to start your own private PKI environment for internal certificate issuance and management? EZCA is a great option for organizations looking to implement a private PKI without the overhead of managing the infrastructure themselves. EZCA is a cloud-based PKI solution that provides a secure and scalable environment for issuing and managing digital certificates.
EZCA offers a 1-month free trial, allowing you to explore its features and capabilities before committing to a subscription. Plus, the Keytos team is available to assist you with any questions or concerns you may have during your trial period. Whether you’re looking to issue SSL certificates for internal websites, Smart Card certificates for user authentication, or device certificates for VPN and Wi-Fi access, EZCA can help you get started with your private PKI quickly and easily.
