Reasons to replace Microsoft Certificate Authority (AD CS) and what to use instead

No matter how necessary, digital transformation can feel overwhelming. This is especially true when existing solutions seem to function optimally. The perfect example? Microsoft Active Directory Certificate Services (AD CS), which has long been a go-to solution for issuing and managing digital certificates.

Microsoft AD CS certainly has its perks: seamless integrations with Microsoft environments and strong support for internal certificates, not to mention, a solid reputation. This is what attracted enterprises to AD CS in the first place and why many have continued to rely on this solution long after it has become evident that alternatives are necessary.

While AD CS can continue to serve traditional on-premises environments effectively for the time being, it often falls short of meeting the flexibility, scalability, and automation demands of modern, cloud-first IT infrastructures.

Fortunately, alternatives are available. Automated certificate lifecycle management (CLM) solutions, such as Sectigo Certificate Manager (SCM), offer many of the core benefits of AD CS but with greater flexibility, improved integrations, and end-to-end automation that helps close visibility gaps and streamline digital certificate management.

Sectigo supports a wide range of use cases, from encryption and user identity authentication to device management across complex environments. Whether used to augment AD CS or replace it entirely, SCM provides the tools and automation needed to thrive in today’s increasingly complex digital landscape.

7 reasons to replace Microsoft AD CS

Microsoft AD CS has long played an important role in helping organizations manage the complexities of the public key infrastructure (PKI). Its appeal was clear: AD CS offered a reliable framework, simplifying critical certificate management tasks while offering tight integrations with Microsoft Active Directory and leveraging the Lightweight Directory Access Protocol (LDAP).

However, as IT environments grow more complex, AD CS may no longer meet many enterprises' core needs. Moving beyond AD CS can feel overwhelming, but, if the following concerns are any indication, this shift is necessary.

1. Security risks and compliance challenges

Calling for on-premises infrastructure and tight management, AD CS can present significant security drawbacks. Because Microsoft CA depends on on-premises infrastructure, it introduces greater security risk unless proactively maintained. One major concern is the system’s vulnerability to misconfigurations and outdated policies, which can lead to weak access controls and certificate misuse. Attackers can exploit these gaps to impersonate users or intercept sensitive communications. If AD CS is not regularly patched and updated, it can expand an organization's attack surface, making it easier for threat actors to exploit known vulnerabilities, escalate privileges, or compromise the certificate authority itself.

Many of these drawbacks relate to manual tracking, which is part and parcel with AD CS workflows. Lacking essentials such as centralized dashboards and consolidated reporting, AD CS makes it far more difficult to keep up with emerging security risks. Managing digital certificates manually also significantly increases the risk of human error, leading to scenarios like expired certificates, downtime, and breaches that can severely disrupt business operations. In a high-certificate environment, manual intervention can quickly spark a chaotic renewal process that leads to significant gaps in coverage.

Microsoft CA is also lacking from a compliance standpoint. This outdated approach makes it difficult to adhere to regulatory standards such as the GDPR. Without centralized automation, meeting GDPR standards, as well as SOC 2 and NIST standards becomes more complex. A lack of visibility and comprehensive reporting prevents consistent policy enforcement and complicates audits.

2. High maintenance and operational costs

From licensing to the rapidly increasing cost of server management, AD CS can spark high maintenance costs that may be further exacerbated by the specialized (and often, extensive) labor needed to ensure that admins maintain manual certificate management strategies.

Hardware expenses are especially significant, extending beyond servers to include expensive database storage, hardware security modules (HSMs), and network infrastructure. As multi-site deployments enter the picture, these costs can increase substantially.

3. Lack of visibility and centralized management

Continued reliance on AD CS increases the likelihood of partial visibility, in which data silos are common and, as a result, certificate management can feel haphazard. Microsoft CA offers only partial visibility and lacks a central dashboard to manage enterprise-wide certificates, making it difficult to track what’s deployed and where. Without a central dashboard, it can be difficult to fully grasp certificate coverage or to understand when rogue certificates create unacceptable risks.

Rogue certificates are often introduced through shadow IT, where departments or individuals deploy digital services without the knowledge or approval of the IT department. Without visibility into these assets, expired or misconfigured certificates can go unnoticed, leading to service outages, failed connections, and potential data exposure. The result can be not just technical disruption but also operational downtime and reputational damage, especially if citizen-facing services are affected.

Unified visibility is best achieved through single pane of glass solutions such as SCM, which prevent certificate blind spots while also maintaining proactive monitoring and consolidated reporting to support effective endpoint management.

4. Manual certificate lifecycle management creates downtime risks

Manual certificate management is not just costly — it is also inherently risky. Simply put, it is difficult to keep up with the extensive amount of digital certificates often found in enterprise environments. If these are not promptly renewed, downtime becomes a real possibility. Microsoft CA lacks built-in automation, which significantly increases the risk of certificate expiration and outages, last-minute renewals that consume valuable IT time, and configuration errors that could inadvertently expose critical systems. This challenge is even more prescient in the midst of shrinking certificate lifespans; organizations that barely managed to keep up while using AD CS will be more likely to fall behind when certificate lifespans shrink to a mere 47 days.

Without built-in automation and with limited integration capabilities, implementing streamlined workflows with AD CS can be difficult. This creates a huge burden on IT departments, which may be forced to dedicate considerable time to manually renewing certificates and may still be prone to errors or misconfigurations. Replacing or augmenting Microsoft CA with automated tools can provide essential capabilities like auto-renewal policies, centralized certificate visibility, and proactive alerting and compliance reporting which can greatly reduce both operational load and risk.

5. Scalability limitations for modern IT infrastructure

Microsoft CA is not scalable enough to satisfy most modern IT needs. This lack of scalability is built into the very structure of AD CS. Yes, AD CS works well for on-premise environments, but what happens when enterprises require the flexibility and accessibility of cloud or hybrid solutions? It becomes especially challenging to scale for cloud-native applications, mobile endpoints, and hybrid or multi-cloud infrastructures, all of which are common in today’s digital ecosystems.

These limitations become even more apparent as organizations strive to handle the needs of the modern remote workforce, which relies on purpose-driven solutions for issuing and managing certificates across diverse digital environments.

6. Limited integration with DevOps & automation tools

As a Windows and Microsoft-centric solution, AD CS lacks the robust integrations that today's enterprises demand, especially given the increasing reliance on non-Microsoft options like Mac and Linux. Tight integrations with Microsoft, although previously helpful, now prompt major limitations, making it more difficult to leverage cloud-native platforms and outside directory services.

Integrations with third-party tools are similarly challenging and may call for significant customizations. Limited support for automation tools increases the likelihood of remaining reliant on manual processes, which, as we've discussed, present a wide array of challenges. Thankfully, alternatives such as SCM offer much-needed support for a wide range of popular DevOps and cloud applications, enabling seamless integration in modern business environments. From the Azure Active Directory (Azure AD) to Akamai, Citrix ADC, and beyond, Sectigo makes the most of a vast integration network.

7. Future-Proofing: Quantum-safe readiness

Moving beyond present challenges, the shift beyond AD CS is worth making because this solution is not equipped to address the most significant security challenges of tomorrow. Quantum computing, in particular, promises to upend everything we currently take for granted about digital certificates and their ability to provide consistent encryption and authentication. Solutions like Sectigo Certificate Manager are proactive with future readiness.

At this point, agility is not only helpful, but absolutely essential. This makes it possible to adjust to evolving security standards and adopt quantum-safe solutions as they become available. Automated CLMs can help organizations achieve crypto agility by making it possible to rapidly deploy updated certificates. Sectigo is at the forefront of this movement, proactively promoting quantum-readiness via the Q.U.A.N.T. strategy.

What to use instead of (or with) Microsoft Certificate Authority?

The need to move beyond AD CS is clear, but that begs a different question: what comes next? There is no one 'right' way to approach this transition, and, depending on current organizational needs or challenges, preferred strategies could vary considerably. In general, however, this effort is likely to involve one of two main pathways:

Option 1: Replace with a Private CA

Private CAs represent an excellent alternative to AD CS, offering centralized control and exceptional scalability across complex hybrid and cloud environments, including platforms such as Azure. Functioning a lot like a publicly-trusted CA but with enhanced oversight and control, private CAs can deliver a tailored approach to issuing and provisioning digital certificates, all while enhancing security and compliance. They also support rapid scaling across hybrid and multi-cloud infrastructures, stronger default security and compliance measures, and seamless integration with DevOps and cloud-native tools. With full visibility and centralized control, organizations gain the transparency and responsiveness they need to manage certificates at scale.

With its private PKI solutions, Sectigo provides a trusted, fully automated platform that enables organizations to reap the full benefits of private certificates with greater efficiency, visibility, and control.

Option 2: Augment Microsoft CA with an automated Certificate Lifecycle Management solution

If a complete transition feels out of reach, consider a middle-ground approach: augmenting Microsoft solutions with an automated CLM solution. This approach can extend the life of previous AD CS investments without risking overreliance on Microsoft CA. By layering automation over Microsoft CA, organizations gain automated CLM, policy enforcement, and advanced reporting, without needing a full replacement. Think of this as a strategy for bridging the gap, bringing the advantages of automated CLM to the forefront while allowing for an easier and more manageable transition. This also enables centralized visibility, streamlined compliance support, and integrations with DevOps tools, all within a CA-agnostic framework that gives you more flexibility over time.

Ready to move beyond Microsoft AD CS?

Microsoft Certificate Authority (AD CS) has served organizations well for many years, especially in traditional on-premises environments. Today, however, our cloud-first ecosystem calls for an evolved approach, complete with unified visibility and CLM automation.

If you're ready to take the next step in this much-needed evolution, look to Sectigo for support. Offering several tailored solutions for augmenting or replacing AD CS, Sectigo provides a reliable pathway to modernizing digital certificate infrastructure. Take the next step and book a demo today.

Want to learn more? Get in touch to book a demo of Sectigo Certificate Manager!

Related posts:

Navigating the complexities: challenges in Microsoft AD CS and the role of automation

Streamlining certificate management: The case for eliminating Microsoft Active Directory Certificate Services

How and why to transition from Microsoft AD CS to a private CA