Enterprise use cases for a private certificate authority
A Private Certificate Authority (CA) provides enterprises with the benefits of PKI authentication while allowing for more control. Learn about the different use cases for your enterprise.
Use cases for private certificate authority
A private Certificate Authority (CA) is an enterprise’s own Certificate Authority, which functions like a publicly-trusted CA, but is run exclusively for a specific enterprise. Many enterprises now operate their own private CA to provide tighter control of their public key infrastructure (PKI) certificates and to ensure identity authentication for the users, devices, and applications that serve that organization only.
The most common use cases for private CAs include:
Device Authentication
User Authentication
Access Control
Secure Web Applications
API Authentication
Mac/Windows devices
iOS/Android mobile devices
Network security hardware and software
Virtual Private Networks (VPNs)
Secure enterprise WiFi access
Internet of Things(IoT) devices
Code signing
DevOps
Email encryption
Document signing
Emerging technologies
Why use a private CA?
A certificate authority is the trusted authority that ultimately vouches for the identity of every single user, machine, or application process accessing an enterprise's IT infrastructure. Without this kind of strong identity authentication, bad actors can programmatically attack any access point in an organization using a man-in-the-middle (MitM) attack designed to steal information or issue false commands which can result in data loss, security breaches, or financial theft. Using a private CA solution, the enterprise sets itself as the final source of truth on its own devices, employees, or processes they know to be trusted inside the network.
The benefits of deploying a private CA are many. First and foremost, by using a private CA, an organization can significantly reduce the risk of unauthorized access to its data and systems. Private CA certificates are restricted to specific people or devices in the organization.
Additionally, the use of private CAs increases the control and agility of certificate issuance, installation, and revocation of digital certificates by allowing network administrators to define and automate PKI standards and practices, rather than creating their own PKI from scratch. This level of control is particularly useful for organizations that need to comply with specific security requirements, like financial institutions.
For example, private CAs define their own certificate expiration policies, as opposed to public CA certificates which are valid for up to 398 days and require renewal every year. So not only does the private CA ensure that certificates expire on schedule and do not cause any disruptions, they can minimize the time-consuming task of renewing hundreds, thousands, or even, millions of certificates across their environment. Similarly, certificate revocation lists (CRLs) can also be used to revoke certificates before they expire or to automate revocation when an employee leaves or a device is decommissioned.
Finally, the control and agility of managing private CA certificates have the added benefit of reducing the speed to market and freeing up employee time for other tasks because the majority of administrative tasks for these internal certificates can be automated.
Most common use cases for private CA
Digital certificates provide the strongest level of authentication and encryption for identity management across an organization's entire IT environment. Here are the most common use cases for private CAs.
Private CA for device authentication
Private CAs authenticate enterprise hardware, network appliances, and industrial equipment, ensuring only approved devices connect to internal systems. Unlike user certificates, device certificates verify machines and services, preventing unauthorized endpoints from accessing sensitive environments. These certificates integrate with firewalls, VPN gateways, and secure tunneling protocols to enforce strict network access controls.
Organizations can automate deployment using Unified Endpoint Management (UEM) platforms like Microsoft Intune, VMware Workspace ONE, and Jamf. Network authentication protocols such as 802.1X, EAP-TLS, and SCEP further ensure only verified devices establish secure connections, supporting zero-trust security and machine-to-machine authentication.
Private CA for user authentication
A private CA strengthens security by issuing certificates tied to user identities, replacing weak passwords with certificate-based authentication. Employees and contractors use these certificates to access enterprise applications, cloud platforms, and VPNs.
Private CA certificates integrate with identity providers like Microsoft Active Directory, Okta, and Ping Identity, enabling single sign-on (SSO) and multi-factor authentication (MFA). They also help enforce privileged access management (PAM), restricting access to high-privilege accounts and reducing unauthorized system changes.
Private CA for access control
A private CA allows organizations to enforce role-based access control (RBAC) by issuing certificates that verify user identity and permissions. This ensures only approved personnel and devices can access corporate systems.
These certificates work with network access control (NAC) solutions like Cisco ISE and Aruba ClearPass, preventing unauthorized users from joining the network. They also support zero-trust security frameworks, where every access attempt is verified before granting entry.
Private CA for secure web applications
Private CAs can secure internal web applications, APIs, and cloud services by issuing certificates that encrypt data in transit and at rest so only authenticated users and systems have access. SSL/TLS certificates protect applications like HR portals and financial tools, while encrypted connections safeguard communication between databases and services. Automation protocols like ACME and configuration tools such as Ansible, Terraform, and Puppet streamline certificate management and security enforcement across enterprise systems.
Private CA for API Authentication
APIs are a critical component of modern applications, enabling systems to communicate and share data. However, APIs are also a common attack target, making authentication and data integrity essential. A private CA issues certificates to authenticate APIs, ensuring that only verified services and applications can interact.
Private CA certificates provide mutual authentication between API clients and servers, preventing unauthorized access and man-in-the-middle (MitM) attacks. They also help enforce secure API communication in industries with strict compliance requirements, such as finance, healthcare, and energy.
Private CA for Mac/Windows Devices
Most organizations require employees to log in to their Mac or Windows machines using a username and password. These passwords often need to be reset every 90 days. A private CA could be used to generate the certificates required for login. Additionally, the operating system could be encrypted to protect against unauthorized access.
Private CAs issue a unique digital identity to each employee’s device. This would replace the need to remember/reset long, difficult-to-remember passwords, and would improve the employee experience by providing a more convenient and secure login process.
Private CA for mobile devices
Employees increasingly access networks and internal resources using iOS or Android mobile devices, including BYOD devices not issued by the organization. Similar to computing devices, Private CAs can issue a unique digital identity to each employee’s mobile device and authenticate the mobile device every time it accesses the network.
Private CA for network security hardware and software
As enterprises adopt new network architectures such as SD-WAN and multi-cloud and hybrid cloud environments, organizations rely upon a variety of network security solutions to protect user devices and critical business systems, including firewalls, web-filtering, and email gateways. But what is protecting those network appliances?
IT teams must secure the identity and access to those network appliances and security services. Private CA certificates offer the necessary strong authentication as well as encryption to protect network infrastructure against malicious attacks and unexpected outages. They also support secure tunneling by issuing certificates for routers and switches making sure only authenticated devices establish encrypted communication channels.
Private CA for VPNs
Virtual Private Networks (VPNs) are often used by companies to create a secure connection between two or more remote sites. A private CA can be used to generate the certificates required for the VPN. This would help ensure that the data passing through the VPN is secure.
Private CAs could issue a unique digital identity to each employee’s device. This would remove the need to issue either USB tokens or mobile apps, and would improve the employee experience by providing a more convenient and secure VPN authentication process.
Private CA for secure enterprise WiFi access
When an employee brings a personal mobile device into the office and attempts to connect to the corporate WiFi, the connection needs to be authenticated and authorized for access to corporate resources. A private CA can be used to generate the certificates required for authentication and authorization of that user and the connection. This helps ensure that the data passing through the corporate WiFi is secure.
Private CA for IoT devices
“Smart” devices that link to one another, to the internet, and to private networked environments are now common across every industry. While connected IoT devices can enable innovative revenue models, improve device functionality, and enhance visibility and control, an IoT environment is only as secure as its weakest link. Because identities and credentials are often hardcoded in IoT devices or simply forgotten and left unmanaged, networks are susceptible to malicious software attacks. By using a private CA, organizations can ensure that only authorized IoT devices connect to their network and can more easily manage identity security and standards across all their IoT devices.
Private CA for code signing
Internal enterprise applications need to be code signed in order to ensure the integrity of code. Private CA code signing certificates are used to digitally sign internal applications and software programs to verify both the source of the file and that the code has not been altered. For internal services and interoperable communications between third parties including those that application program interfaces (APIs), a private CA can be used to generate the certificates required for code signing.
Private CA for DevOps
Private CA certificates also help secure DevOps containers and code. Often DevOps teams don’t want to spend their time on certificate management, and yet they need to integrate PKI to protect containers and the code within them. Using private CA, the DevOps team can incorporate compliant certificate processes into their normal workflow and integrate PKI into the continuous integration and continuous deployment (CI/CD) pipeline, orchestration frameworks, and third-party key vaults.
Private CA for email encryption
Email is still a popular way to share confidential information. However, it can be vulnerable to interception and theft. A private CA can be used to generate S/MIME certificates required for email encryption. This would help ensure that all confidential information is secure when transmitted and stored.
Private CA for document signing
Demand is growing for digital document signing, as businesses look to improve efficiency and security in their document workflows and to eliminate outdated paper methods are expensive and often lead to errors. Digital signatures are the most advanced and secure type of electronic signature and take the secure document exchange a step further than simple e-signatures. Digital signatures provide a way to ensure the integrity, authentication, and non-repudiation of documents.
A private CA can be used to digitally sign and encrypt documents and provide and protect the files from unauthorized access or manipulation. Employees could use a digital ID to encrypt the files on their desktop, company servers, or cloud servers. This means that when a document is digitally signed, the employee can be sure that the files are secure and can only be accessed by authorized individuals; and the recipient can be sure that it has not been altered and that the signer is who they say they are.
Private CA for emerging technologies
As businesses adopt AI, blockchain, and quantum computing, private CAs provide strong authentication and encryption for these evolving technologies. In AI security, certificates protect AI models and machine learning data from unauthorized modifications, ensuring that systems remain trustworthy. For blockchain and decentralized identity, private CA certificates verify blockchain transactions, secure smart contracts, and authenticate participants in distributed networks. With quantum computing on the horizon, organizations are also preparing by adopting quantum-safe cryptographic algorithms, ensuring long-term security for encrypted data and communications.
What is the difference between private CA and public CA?
When you're providing a service that's open to the general public on the Internet, you need to use a certificate signed by a third-party "publicly trusted" Certificate Authority. This assures people that they're connecting to your website or your server and nobody can listen in on their communication. The public SSL/TLS certificate or public digital certificate will ensure the security of your communication over the public Internet.
These publicly trusted certificates are trusted by almost all popular operating systems, hardware, software, and services that are in use in the world today. This is accomplished by the presence of public roots, which are embedded in virtually all machines and software that exist. For example, every popular internet browser like Google Chrome, Mozilla Firefox, Microsoft, and Apple Safari has a root store. And that root store contains public CA keys associated with public certificate authorities. In order to maintain this public trust, the public CA must follow a number of requirements and standards set forth by entities like the CA /Browser Forum.
However, if you're providing a service that's only for your organization, you can opt to use private CA, ostensibly your own CA, to issue certificates. Enterprise security teams use their own private CA to get the benefits of PKI authentication and encryption capabilities, but with the ability to fully control policies and configurations for the specific needs of their organization and exclusively on their own network. Since private CA is specific to an enterprise, it is not considered publicly trusted. This means that certificates issued by a private CA should only be used within the trusted members and infrastructure of the enterprise.
Both private CA and public CA are based on the same PKI architecture. The digital certificate, whether issued by private CA or public CA relies on a key pair - a private key and a public key. The private key is used to sign certificates and must remain secret and stored securely, often in a Hardware Security Module (HSM). Then the public key is used to verify those signatures. The key pair is mathematically related so that whatever is encrypted with a public or private key can only be decrypted by its corresponding counterpart. Additionally, public and private keys are generated using strong cryptography, such as RSA and ECC algorithms, that cannot be easily broken by cybercriminals and other malicious actors.
Both public and private CAs rely on certificate signing requests (CSR), or a block of text that is generated by a user on their device and contains specific information about the user and the device. This information is used by the CA to generate a digital certificate, such as an SSL certificates, that is specific to the user and their device.
The way a private CA works is simple: the organization creates its own trusted root certificate and uses that root CA certificate to issue intermediate CA certificates with different validation requirements. This allows the organization to fully control the certificates that are issued and ensures that only authorized devices can access the network. A CA-signed cert is considered a trusted certificate, while self-signed certificates are not.
Sectigo offers both private CA and public CA certificates
Sectigo is a publicly trusted CA and member of the CA/Browser Forum as well as offers Private PKI for organizations to use their own private CA. Many organizations prefer to have all operational aspects of their Private CA including hosting, maintenance, security, and compliance is handled by a third party like Sectigo.
Sectigo’s Private PKI solution gives customers a complete, managed PKI solution that solves problems associated with establishing and managing internal PKI throughout the entire certificate lifecycle. With Sectigo, enterprises can automate certificate management, including certificate issuance, deployment, revocation and renewal processes, and authentication controls. For enterprises that already have their own Private Root CA or use Microsoft CA (MSCA) for Windows-based servers and devices, Sectigo Private PKI works alongside the existing private CA or MSCA within Sectigo Certificate Manager so that organizations can secure all devices and applications from a single platform.
Learn more about Private PKI and its key use cases by downloading Sectigo’s eBook: An Introduction to Private PKI.