How an Intermediate CA Works and Benefits Your Business

Here’s a scenario: You’re leading a manufacturing company producing the latest innovative Internet of Things (IoT) device. As the idea comes to life, launch preparations are underway, and the rollout is just around the corner, late-stage concerns come to mind. Are all your devices equipped with valid CAs? Will each device offer your expected level of security to product users and your business?   

By establishing an Intermediate CA, also referred to as a Subordinate Certificate Authority (Subordinate CA), organizations can issue unique digital certificates to each individual device during production. These subordinate certificates authenticate the devices when they connect to the company’s network, ensuring secure communications and preventing unauthorized access. This approach secures the devices while also simplifying the certificate management process across the entire product line. 

How a Subordinate CA Works 

Subordinate CAs are vital components within a Public Key Infrastructure (PKI). In PKI, a chain of trust is a hierarchical model that ensures the authenticity and integrity of digital certificates. It starts from a Root Certificate Authority (Root CA) and extends through an Intermediate Certificate Authority (CA) down to the End-Entity (or leaf) Certificate, such as a website’s SSL/TLS certificate.  

Each certificate in this chain is signed by the one above it, creating a verified path from the Root CA to the End-Entity Certificate. This signing process ensures that any certificate issued by the subordinate CA inherits the trustworthiness of the Root since it ultimately links back to it. The chain of trust hierarchy between the trusted Root Certificate and subordinate CA is illustrated below: 

Frequent Uses for Sub CAs  

The following are common scenarios in which organizations typically deploy Intermediate CAs:    

 Enterprise PKI Infrastructure    

• Internal SSL/TLS certificates securing internal networks and applications   
• Employee authentication via digital certificates   
• Document signing and code signing ensure authenticity and integrity   

Managed Service Providers (MSPs)    

• Efficiently managing multiple clients’ certificate environments under one unified infrastructure   
• Customizing certification policies tailored specifically to individual client requirements   

Compliance in Regulated Industries    

• Meeting stringent regulatory standards such as HIPAA (healthcare), PCI DSS (finance), or FPKI (government)   
• Simplifying compliance audits through externally managed public trust infrastructure   

Branded Resale Certificates    

• Issuing certificates uniquely branded for specific partners or resellers   
• Enforcing strict CA-level constraints to protect brand integrity and ensure compliance   

Unique Key Pair Management    

• Issuing each certificate with its own unique cryptographic key pair   
• Enhancing security by preventing unauthorized access and simplifying revocation processes if keys are compromised   

 For businesses, it is a best practice to segment issuing CAs based on the nature of the certificates they distribute. For example, if your organization deals with smart card certificates and SSL/TLS certificates, then it is recommended to have separate issuing CAs for each type.   

The Importance of Subordinate CAs for Businesses 

A Sub Certificate Authority offers several benefits to meet an organization’s business needs, including:  

1. Enhanced Security: By delegating certificate issuance to Subordinate CAs, the Root CA’s private key can remain offline and secure. This compartmentalization means that if a Subordinate CA is compromised, the Root CA wouldn’t be impacted by any negative impacts.   
2. Operational Flexibility: Businesses can operate their own Subordinate CAs to issue certificates tailored to their specific needs, such as internal applications, devices, or regional operations. This autonomy allows for customized certificate policies and practices.   
3. Brand Recognition and Trust: Operating a Subordinate CA under a business’s brand can enhance customer trust. For instance, SSL.com offers custom-branded Subordinate CAs, allowing organizations to issue certificates that display their company name as the issuer, reinforcing brand identity.   
4. Scalability and Management: Subordinate CAs facilitate the management of large volumes of certificates across various domains or services to help streamline operations and ensure consistent security practices. 

The Specific Benefits of SSL.com’s Managed Subordinate CA Infrastructure  

SSL.com provides organizations with a fully managed, publicly trusted Sub CA solution, giving our customers clear advantages over managing their own internal PKI infrastructure.   
 
The primary benefits include:   

Fully Managed Infrastructure and Simplified Operations    

SSL.com handles all infrastructure setup and maintenance aspects, including secure hosting environments, Hardware Security Modules (HSMs), certificate management software, backups, and disaster recovery.   

We help our customers avoid costly upfront investments in hardware/software and ongoing operational overhead. Certificate issuance requests are efficiently processed through SSL.com’s managed systems. This allows your internal teams to focus on core business objectives rather than handling the day-to-day complexities of PKI management tasks.   

Additionally, we can provide custom-branded Subordinate CAs, enabling your business to issue publicly trusted certificates under your brand without investing in an extensive PKI infrastructure.

Built-in Compliance and Audit Readiness    

Our managed infrastructure strictly adheres to global PKI standards. Our team conducts regular external audits to reduce internal compliance burdens significantly.   

Clear documentation via Certification Practices Statements (CPS) ensures transparency in all our procedures. Organizations benefit from built-in compliance assurance without dedicating extensive internal resources toward audit preparation or regulatory adherence. 

 Enhanced Security and Risk Management    

SSL.com brings over 20 years of layered cybersecurity defense strategies to businesses and governments in over 180 countries. Our team of specialists helps ensure:   

• Your Root CA remains securely offline 
• Cryptographic keys are generated securely during controlled key ceremonies conducted by SSL.com’s expert personnel   
• Each certificate issued has its own unique cryptographic key pairing, significantly enhancing security posture and mitigating the risks associated with private key compromise   
• Clearly defined revocation procedures are proactively managed by SSL.com in response to security incidents or brand changes; This provides continuous trustworthiness of issued certificates    

Get Started: Creating Your Intermediate CA with SSL.com  

Establishing your publicly trusted Subordinate CA with SSL.com involves clearly defined steps to simplify the onboarding process:   

1. Business and Legal Agreement 

• Clearly defines responsibilities around issuance policies, compliance expectations, pricing structures, and brand protection requirements  
• Includes identity validation processes that ensure strict adherence to industry regulations—particularly crucial in branded resale scenarios 

2. Secure Key Ceremony & Technical Setup 

• SSL.com securely generates cryptographic keys during controlled ceremonies performed by expert personnel   
• Subject Distinguished Name (DN) verification ensures accurate alignment with organizational branding requirements
• Cryptographic keys are securely stored in accordance with industry best practices and within SSL.com’s secure infrastructure  

3. Ongoing Coordination & Support 

• Our dedicated teams of PKI specialists, validation experts, and IT support help ensure strict adherence to industry constraints throughout the lifecycle of certificate issuance and management
• Through continuous monitoring, our teams externally manage logging, auditing, and revocation management  

Let our team take the last-minute concerns of PKI out of your operations to help you focus on your products, performance, and customers’ needs. 

Learn how we can help your organization enhance security, operational flexibility, and scalability with a custom PKI strategy.