What is certificate lifecycle management?

Certificate lifecycle management (CLM) is the formal process of managing and securing an organization’s digital certificates. CLM aims to streamline and automate each stage of the certificate lifecycle: inventory, issuance, deployment, monitoring, renewal, revocation and disposal.

Digital certificates are electronic documents that use public key cryptography to prove the identities of their bearers. They’re often used to authenticate nonhuman identities (NHIs) such as websites, servers, applications and AI agents.  

As NHIs proliferate through the enterprise network—driven by DevOps, cloud environments, artificial intelligence (AI) and machine learning (ML)—certificates become an increasingly important component of identity and access management (IAM).

However, the explosion of NHIs also means an explosion of certificates, which must be protected from threat actors like any other digital credential.  

And certificates carry an added complication: expiration dates. 

By design, certificates don’t stay valid forever. If one expires before it can be renewed, it can lead to major disruptions, service outages and downtime. Customers might not be able to reach a website. Critical pieces of network infrastructure might cease to function. Payment processors can go down. 

Certificate lifecycle management aims to give organizations tools, tactics and strategies to simplify key certificate workflows, such as tracking certificate status, controlling access and renewing and revoking certificates. In this way, CLM can help mitigate certificate fraud, theft and misuse while preventing costly, unexpected outages. 

Digital certificates—also called X.509 certificates, after the X.509 standard that defines their format—are electronic documents used to verify digital identities. Certificates are mainly used by nonhuman and machine identities such as servers, software, computers and Internet of Things (IoT) endpoints.

Certificates depend on a framework called public key infrastructure (PKI), which uses asymmetric cryptography to validate entities’ identities and secure communications between them.  

More specifically, asymmetric cryptosystems use two different keys—a public key and a private key—to encrypt and decrypt data. Anyone can use a public key to encrypt data. However, only the holders of the corresponding private key can decrypt that data.

Digital certificates prove that a particular private key belongs to a particular entity, and possession of an authentic certificate is often taken as proof of that entity’s identity.  

In a sense, a certificate is a bit like the deed to a house: It records who a piece of property (the key) belongs to, and if someone holds the deed, they are likely the legitimate owner of that property.

But this analogy also reveals the limitations of certificates and the importance of securing them. If a bad actor steals a certificate, they can pretend to be a trustworthy entity—and other users might believe them, with potentially disastrous consequences.  

For example, say a threat actor steals or forges a copy of a legitimate website’s certificate. The attacker then makes a malicious copy of the website designed to steal users’ credentials. Because the attacker has a seemingly authentic certificate, web browsers will think their phishing site is the real deal, and users won’t receive any warnings that the site is a fake. 

To mitigate the risks of falling into the wrong hands, most certificates are valid only for a limited period of time. Certificate expiration is a cybersecurity measure, much like regular credential rotation. Even if attackers get their hands on a valid certificate, it will be of limited use—that is, if the real owner doesn’t revoke it first. 

A certificate typically includes:

• The subject: The person, machine, website or other entity the certificate belongs to. Certificates might also record Subject Alternative Names (SANs), which are other names authorized to use the certificate. For example, the certificate for a website might also record all of that site’s subdomains.  
   

• The issuer: The certificate authority (CA) that issued the certificate.  
   

• The validity period: When the certificate goes into effect and when it expires.
   

• The subject’s public key: Other users—human or nonhuman—can use this public key to encrypt their communications with the certificate subject. Because the subject is the only one with the associated private key, only the subject can decrypt these messages to see what they say.
   

• The issuing certificate authority’s digital signature: This signature confirms that the certificate was issued by a legitimate CA, which generally means it can be trusted. 

Most certificates are issued by a certificate authority (CA), a trusted third party that verifies the identities of certificate requesters and grants them trustworthy certificates.

CAs are typically members of the CA/Browser Forum (CA/B Forum), a consortium that sets standards for certificates and certificate authorities. It is this affiliation, and adherence to CA/B standards, that earns a CA’s trust with other organizations, applications and users. 

Well-known CAs include the nonprofit Let’s Encrypt and private organizations such as GlobalSign, DigiCert and Microsoft Active Directory Certificate Services.

The issuance process works as follows:

1.  The entity that needs a certificate (“the subject”) generates a public-private key pair.
   
   
2. The subject sends a certificate signing request (CSR) to its chosen CA. This request includes the subject’s public key as well as the information needed to prove the subject’s identity to the CA. For example, a CSR for a website might need to include proof that the requester owns the website in question. 
   
   
3. The CA reviews the CSR, verifies the subject’s identity and issues a certificate. The certificate is cryptographically signed by the CA’s own private key to prove that it is legitimate.
   
   
4. The certificate is installed wherever it’s needed—a server, a device or elsewhere.

In essence, certificates are a vouching system. The subject provides the CA with the proof needed to establish its digital identity. The CA signs off, saying: This identity is legitimate—and here’s a key so others can communicate with it securely. Because the CA is trusted, its certificates are trusted.

Entities can also generate their own self-signed certificates, but these carry little weight outside of closed environments where all parties already trust one another.

Sometimes called SSL certificates or TLS certificates, these are among the most widely used certificates. Their name comes from two cryptographic communications protocols used on the internet: Transport Layer Security (TLS) and the largely deprecated Secure Sockets Layer (SSL).

TLS/SSL certificates authenticate web servers and provide web browsers with the server’s public key, enabling secure, encrypted connections between servers and clients. 

There are three main types:

• Domain validated (DV): Verifies website ownership only. 

• Organization validated (OV): Verifies both website ownership and the organization behind the website

• Extended validation (EV): The most stringent type, requiring manual verification by a human. Used in industries that demand the highest levels of trust, such as finance and banking. 

Also called S/MIME certificates (after the Secure/Multipurpose Internet Mail Extensions standard), these enable identity verification and encrypted communication for email.

These verify that a program, application, patch or other piece of code is authentic and has not been tampered with. They work by applying a digital signature to the code at the time of publication. The developer signs the code with their private key, and any user or system that runs the code can verify that signature against the corresponding public key. 

CLM tools, also known as certificate management solutions, help simplify, secure, streamline and automate much of the certificate management lifecycle. In fact, many core aspects of certificate management—such as surfacing all the active certificates in a network and renewing certificates before they expire—are virtually impossible without these tools.

Common capabilities of CLM tools include: 

• Automated discovery and inventorying of all certificates, capturing key details such as ownership, installation location and expiration date. 

• Dynamic, on-demand certificate generation for greater security and streamlined certificate access.

• Fully or partially automated CSRs, including the ability to generate new key pairs, secure transmissions of CSRs, integrations with trusted CA systems and the ability to create self-signed certificates.

• Remote provisioning, so certificates can be installed directly to the appropriate devices and services from a single central control panel.

• Monitoring and compliance logs to track certificate use and validity, detect pending expirations and identify vulnerabilities such as weak or deprecated cryptographic standards.  

• Notifications of expiring certificates and automated renewals to prevent outages.

Nonhuman identities make up an increasing proportion of the enterprise network. Estimates vary—from 45:1 to 92:1—but in the average IT system, nonhumans significantly outnumber humans.

These NHIs rely on certificates for authentication and access control. Managing all of these certificates manually is not only inefficient—it isn’t scalable.

Without a formal CLM process and the right tools, certificates can slip through the cracks, exposing organizations to all kinds of risks.

For security reasons, certificates only remain valid for short periods—and they’re growing shorter. In March 2029, new CA/B Forum standards go into effect requiring SSL/TLS certificates to be renewed every 47 days. 

If certificate renewals are handled manually, deadlines can easily be missed, leading to downtime and introducing security vulnerabilities. Expired certificates can disrupt access for legitimate users and create openings for illegitimate ones, such as opportunities to pass forged certificates or exploit “fail open” behaviors. 

(In this context, “failing open” means that, if a certificate validity check cannot be carried out, the system will continue allowing traffic unless or until invalidity is established. Many certificate systems fail open by default, because it can be costly to read a CRL or perform other validity checks every single time a certificate is used.)

Automated renewal, then, is as much a security solution as an operational one. CLM tools help ensure uptime while mitigating the risk that threat actors can steal or misuse valid certificates.  

In DevOps-focused, hybrid and multicloud environments—where certificates might exist on-premises, remotely, ephemerally and in cloud-based infrastructure—keeping track of all an organization’s certificates can be difficult. 

CLM tools enable regular, comprehensive scanning for new and existing certificates across applications, services and infrastructure. These tools can also maintain inventories, creating a cryptographic bill of materials (CBOM) to catalog algorithms, keys and certificates. 

A complete certificate inventory can capture each certificate’s owner, purpose, endpoint, issuer, renewal path, deployment path and the potential blast radius if the certificate were to expire unexpectedly.

Quantum computing represents an emerging use case for CLM. As quantum capabilities advance, they threaten to break traditional encryption methods and erode digital trust. CLM tools can help organizations respond to quantum-driven shifts by rapidly adopting new encryption standards and quickly revoking outdated certificates that rely on obsolete encryption methods. 

Organizations are beginning to plan for post-quantum cryptography across their certificate landscapes, with solutions now focusing on quantum-safe public key infrastructure (PKI) and emerging algorithms such as CRYSTALS-Kyber for key encryption and CRYSTALS-Dilithium and Falcon for digital signatures.

But organizations need to know where their certificates are—and what encryption they’re using—for these transitions to succeed. One missed certificate can be just what attackers need to break in. 

Through comprehensive discovery and inventory, plus automated renewals and revocations, CLM tools and processes can help organizations ensure that certificates adhere to the most current standards for cryptographic security.