7 Reasons Why You Need To Replace Your Microsoft CA

Maintaining a robust and efficient Public Key Infrastructure (PKI) has never been more important for digital security. PKI is not only used to protect public-facing websites and applications but also to secure machine-to-machine communications across a wide range of enterprise use cases, ensuring data privacy and integrity. As the application of PKI expands, there is a greater focus on the security, compliance and effectiveness of PKI and its overall management.

Many organizations currently rely on Microsoft Certificate Authority (CA), otherwise known as Active Directory Certificate Services (ADCS), for their private PKI needs. Microsoft CA has long been the preferred solution for enterprises operating within Windows environments, providing a familiar and integrated method for managing private trust digital certificates. However, despite its widespread adoption, Microsoft CA presents several challenges that hinder an organization’s ability to maintain a secure, scalable, and efficient PKI infrastructure.

Here are some of the key limitations of using Microsoft CA and the reasons why organizations should consider alternative modern approaches for their private or in-house PKI.

1. PKI Team Churn

Deploying PKI in-house is a complex undertaking that involves procuring and maintaining hardware and software, designing the PKI framework, keeping it secure, and running highly available validation services like OCSP. Once deployed, Microsoft CA requires continuous maintenance to ensure optimal performance and security. Regular software updates, security patches, and system monitoring are essential tasks that require skilled PKI personnel. However, when the PKI experts who initially set up the infrastructure leave the company, IT teams often struggle to manage the legacy system due to skill or knowledge gaps. This dependence on specialized personnel can create operational challenges and vulnerabilities, undermining the effectiveness of this critical infrastructure and making it difficult for ill-equipped IT teams to ensure the private CA’s security, integrity, and performance.

2. Hardware End-of-Life or CA Expirations

Like most things, PKI also comes with a shelf life. Over time, the hardware components supporting the PKI infrastructure, such as servers and Hardware Security Modules (HSMs), age and eventually need refreshing, typically every 4-5 years. In October 2023, Microsoft discontinued support for Windows 2012 Servers, prompting organizations running their Microsoft CA on these servers to either upgrade the servers or plan for a migration before the end-of-service deadline. This process is labor-intensive and time-consuming as it involves a host of servers. Failure to upgrade in time exposes systems to security threats as outdated servers become increasingly vulnerable to attacks without security patches. Hardware failures present another challenge, including the risk of a lost Certificate Authority (CA). For example, if the hardware is not refreshed, it could fail, rendering the private key and other essential components of the CA infrastructure lost, inaccessible, or compromised. This situation can have serious security implications as it disrupts certificate authentication. Further, it’s not just the hardware that can expire; the root CA itself has a limited lifespan and usually needs replacement every 5-10 years. If the root CA expires unexpectedly, all certificates issued under it will become invalid, causing widespread outages and disrupting the entire certificate chain of trust.

3. Lack of Cross-Platform Support

Microsoft CA is primarily designed to cater to Windows environments. While this integration works well within homogeneous Windows networks, it poses significant challenges in today’s diverse IT environments, where organizations utilize a mix of operating systems, including macOS, Linux, iOS, and Android. This diversity needs a flexible and inclusive PKI solution. Microsoft CA only supports certificate auto-enrollment for Windows endpoints. With a lack of cross-platform support for non-Windows endpoints complicating certificate management, automation, integration, and security, IT teams struggle to implement and manage PKI consistently across all devices and systems within the enterprise, leading to security gaps.


Webinar: Simple Steps to Migrate Your Microsoft CA to PKI-as-a-Service

4. New Technologies and Use Cases

As hybrid and multi-cloud environments become the norm, organizations have started to extensively adopt new cloud-native technologies and practices, such as microservices, containers, IoT, DevOps, and others. These modern-day use cases demand agility and high-speed certificate issuance at scale. PKI must be adaptive and agile to meet rapidly changing certificate requirements. However, Microsoft CA is a legacy infrastructure and is not built for the cloud. It lacks support for newer auto-enrollment protocols like ACME, widely used in DevOps, and does not integrate with essential DevOps toolsets, ITSM, SIEM, and MDMs. This lack of integration makes Microsoft CA a bad fit for modern enterprises.

5. A Bottleneck for Acquisitions and Organic Growth

Using a Microsoft CA can also complicate private PKI management during mergers and acquisitions. When two organizations with separate Microsoft CA infrastructures merge, aligning their PKI systems becomes a complex and time-consuming process. Each CA may have different configurations, policies, and certificate hierarchies, leading to interoperability issues. Additionally, consolidating these infrastructures requires meticulous planning to avoid service disruptions and ensure continuous certificate trust and validity. The intricacies involved in migrating certificates, synchronizing policies, and maintaining secure communications can overwhelm IT teams, creating vulnerabilities and operational inefficiencies during a period that demands seamless integration and heightened security.

6. Security and Compliance Risks

With cyberattacks increasing, data privacy regulatory bodies have grown more stringent about compliance. Organizations managing private PKI are expected to follow best practices to ensure compliance. For instance, in compliance-driven industries, such as Government, FinTech, Healthcare and others, using FIPS-compliant HSMs to protect private keys is mandatory. In many cases, organizations initially deploy a Microsoft CA (without HSMs) to serve a single use case and then gradually expand it over time to serve new use cases, yet fail to adhere to the new best practices or new compliance requirements. Also, when organizations install multiple Windows root CAs for different purposes, enforcing proper policies and governance across all CAs becomes a challenge, giving rise to auditing and compliance issues.

7. High TCO (Total Cost of Ownership)

As the demand for private trust certificates increases, private PKI must scale up to meet business requirements. Scaling a Microsoft CA infrastructure is particularly challenging, requiring investments in additional hardware, software licenses, and skilled personnel. These costs can quickly add up, increasing the overall TCO for Microsoft CA.

Rethink Your PKI with Simple, Secure, and Scalable PKI-as-a-Service (PKIaaS)

While Microsoft CA has long been a trusted solution for implementing private PKI, it hasn’t evolved enough to meet today’s fast-changing PKI needs. Trying to workaround the limitations of Microsoft CA is only going to complicate private PKI implementations, leaving your organization susceptible to certificate-related outages, compliance issues, and security breaches. It’s time to consider alternate modern approaches, such as PKIaaS, that address the challenges of managing private PKI without undermining its effectiveness.

PKIaaS is externally hosted, fully managed, and delivered via a cloud-based software-as-a-service (SaaS) platform. The PKIaaS provider handles all of the required infrastructure components, including the hardware, software, and security of the cloud environment, eliminating the burden and complexity of managing the PKI on-premises.

Migrate Effortlessly from Microsoft CA to PKIaaS with AppViewX

The AppViewX AVX ONE Platform offers a ready-to-use, scalable and compliant PKI-as-a-Service that simplifies the complexity of operating a private PKI. AVX ONE combines PKIaaS with certificate lifecycle management automation providing a centralized solution for modern private PKI and end-to-end certificate lifecycle management. Leveraging the integration between AVX ONE PKIaaS and native Windows Auto-enrollment, you can seamlessly provision certificates from AVX ONE PKIaaS, replacing certificates issued from a Microsoft CA, without any additional client footprint. The AVX ONE PKIaaS lift-and-shift feature works directly with Group Policy and native Windows Auto-enrollment to streamline the migration from your Microsoft CA to AVX ONE PKIaaS. AppViewX handles the heavy lifting, while you shift to a modernized PKIaaS in minimal time.

To learn more about how you can seamlessly migrate from your Microsoft CA to AppViewX AVX ONE PKIaaS, register for our upcoming Webinar: Simple Steps to Migrate Your Microsoft CA to PKI-as-a-Service.


  • ACME
  • Certificate authority
  • certificate lifecycle management
  • FIPS-compliant
  • HSMs (Hardware Security Module)
  • Microsoft CA
  • PKI
  • pkiaas
  • private PKI
  • Security and Compliance Risks

About the Author

Krupa Patil

Product Marketing Manager

A content creator focused on providing readers and prospective buyers with accurate, useful, and latest product information to help them make better informed decisions.

More From the Author →

Related Articles

Secure PKI Orchestration for DevOps in a Containerized CI/CD Environment

| 5 Min Read

AppViewX AVX ONE CLM – Managing Java TrustStore with Google Cloud Platform

| 5 Min Read

AppViewX Integration with Intune for Certificate Automation

| 5 Min Read