Blog Post Mar 11, 2024

What is a Private CA? How to manage internal certificates

Secure internal communications efficiently! Establish a private Certificate Authority (CA) with Sectigo for cost savings, flexibility, and robust data protection within your organization. Explore benefits, risks, use cases, setup, and solution selection.

1. Private PKI: when and how to use a Private Certificate Authority

2. Benefits and risks of using a private CA

3. Use cases for an internal Certificate Authority

4. How to set up and manage internal certificates with private PKI

5. How to set up a private CA

6. The right private PKI solution for your enterprise

Private PKI: when and how to use a Private Certificate Authority

A public Certificate Authority (CA) issues digital certificates (e.g., SSL/TLS certificates) to secure communication between an organization and an external party. But what about internal communications within an enterprise?

You can save costs and enhance flexibility with a private Public Key Infrastructure (PKI) to secure data exchange, authenticate users and devices, and ensure data integrity and confidentiality within your organization's internal network.

Enterprises must establish their own CA(s), also called a private CA, to create a private PKI. A private CA issues certificates to support data encryption, user and device verification, and secure internal communication.

Let's explore what a private CA does, the benefits and risks of using one, typical use cases, how to set up a private PKI, and how to choose the right solution for your enterprise.

What is a private Certificate Authority?

A Certificate Authority is a public key infrastructure that issues certificates to validate identity’s of entities. A private CA, or internal CA, is used in an enterprise that issues private certificates for servers and users within the organization.

Many enterprises use private CAs to provide robust Identity and Access Management (IAM) mechanisms to authenticate and validate the identity’s. These certificates enable tighter control of users and devices that exclusively serve the organization. They support mobile and Internet of Things (IoT) device identification, virtual private networks (VPNs), network security hardware, intranet sites, and more.

Certificates issued by private CAs are for internal use only. Unlike those issued by public CAs, they can't be used by clients, operating systems, or services. However, they're highly customizable with fewer configuration constraints and provide a lower-cost option to safeguard internal communications.

Private CA certificate vs. self-signed certificate

Self-signed certificates aren't signed by a publicly trusted CA. Instead, the certificate is created, issued, and signed by itself that is utilized in various location/operation. Unlike private CA certificates generated from a secure root maintained by an internal CA, self-signed certificates act as their own root. Moreover, a private CA certificate is automatically trusted, while each self-signed certificate must be verified manually and individually.

Benefits and risks of using a private CA

Many organizations use a private CA because of the lower cost, especially for managing numerous certificates that require frequent reissuance or renewal. For example, Microsoft CA integrates with Active Directory, which helps streamline the certificate management process.

Private CAs allow organizations to keep some of their infrastructure in-house for security and added control. You can create/use certificate types unavailable through commercial public CAs and customize your certificate policies to meet unique business, governance, and compliance requirements.

However, using private CA certificates also involves some hurdles. You need specialized knowledge to properly manage a private CA/PKI and operate at scale. Also, finding the right software to meet your needs can be challenging. For instance, Microsoft CA lacks some critical elements many organizations require.

Since private CAs don't need to follow the same industry regulations and standards as commercial public CAs, you can miss out on opportunities to enhance security and interoperability. Additionally, you may overlook industry regulations that apply to your private CA, leading to legal and financial consequences.

So how do you balance the pros and cons of using a private CA? There's no one-size-fits-all answer—it's all about using it correctly and in the right situation. Let's examine some common use cases to see how a private CA can deliver the most benefits.

Use cases for an internal Certificate Authority

Most enterprises use private CAs for internal websites and communications (e.g., web services and server-to-server). They may implement certificate-based authentication to protect against unauthorized access and enhance user experience.

Here are some common use cases for a private CA:

Network security for SD-WAN and hybrid or multi-cloud environments: A private CA offers robust authentication and encryption to protect network infrastructure, including hardware and software.
IoT device authentication: Private CA certificates ensure that only authorized IoT devices can connect to the organization's network, streamlining identity security management and applying consistent standards across all devices.
VPN security: A private CA generates certificates to support VPNs for secure connections between two or more remote sites. They replace USB tokens or mobile apps to improve employee experience while enhancing the security of the authentication process.
DevOps security: Private CA certificates secure DevOps containers and code by integrating PKI into the continuous integration and continuous deployment (CI/CD) pipeline, orchestration frameworks, and third-party key vaults.
API authentication: A private CA generates code-signing certificates to ensure the integrity of code used in application programming interfaces (APIs) for secure and interoperable communications with third parties.

How to set up and manage internal certificates with private PKI

A scalable and cost-effective certificate management process is essential for reaping the benefits of a private PKI issuing private certificates. Also, consider various deployment scenarios and specific security concerns based on your organization's business and compliance requirements.

A privately managed solution is the best option for most enterprises. With the right software, you can handle your private and public certificates on a single platform to streamline workflows and get expert support to resolve issues promptly. These highly scalable platforms can accommodate rapid infrastructure expansion and help you lower the cost of managing certificates over time.

There are different deployment scenarios for private PKI solutions. You may choose from these deployment architectures when you use Sectigo's private PKI solution:

Sectigo hosts the Private Root CA and the Issuing CA on the cloud on your behalf.
You host the Private Root CA of your choice, and Sectigo hosts the Issuing CA(s) for you.
Sectigo hosts the Private Root CA, and your organization hosts the Issuing CA(s).

How to set up a private CA

Here are the key steps for implementing a private CA:

Define the scope, purpose, and policies for the private CA. Then, identify the types of certificates you need and their use cases.
Choose a private PKI solution based on your requirements, considering factors like features, support, deployment options, and scalability.
Set up your infrastructure, including the Private Root CA and Issuing CA(s), and set up the hardware and cloud resources.
Configure the private CA based on your policies, such as specifying key algorithms, certificate validity periods, and other parameters.
Integrate the private CA with existing systems and applications that require certificates. You may need to (re)configure web servers, applications, and network devices.
Conduct thorough testing to validate issuance, renewal, and revocation processes throughout the certificate lifecycle.

Also, implement continuous monitoring and regular maintenance. Review your private CA configuration periodically to incorporate the latest best practices and security standards.

The right private PKI solution for your enterprise

A private PKI solution must provide you with a streamlined process to issue and manage all your internal certificates while enhancing the security of your infrastructure.

Sectigo's Private PKI solution is a complete, managed platform. It allows you to issue and manage privately trusted certificates to support secure communication and effective end-to-end authentication across the enterprise environment. Along with the Sectigo Certificate Manager, a CA-agnostic certificate lifecycle management platform, you can manage all your private and public certificates in one place.

Learn more about our managed private PKI solution and request a demo to see how we can help you reap the benefits of private CA certificates.