Jellyfish

What is the difference between Private PKI and Public PKI?

Private PKI:

A Private Public Key Infrastructure (PKI) is a system designed to manage digital certificates within a controlled, internal environment. It enables organisations to issue, manage, and revoke certificates for internal systems, devices, and users. It provides full control over certificate policies, ensuring tailored security and compliance. For example, a company might use Private PKI to secure internal networks, IoT devices, or employee authentication, keeping all certificate data private and secure within the organisation.

Public PKI:

Public PKI involves third-party Certificate Authorities (CAs) that issue certificates for public-facing applications, such as SSL/TLS certificates for public websites. These certificates are designed to be trusted across public networks like the internet and follow standardised policies set by external CAs. For instance, a public CA might issue a certificate to secure a website like "example.com", making it verifiable by any browser worldwide.

Key differences:

  • Control and customisation: Private PKI allows organisations to define their own certificate policies, such as validity periods or encryption standards, tailored to specific needs. Public PKI relies on Public CA-defined policies with less flexibility.
  • Security and privacy: Private PKI certificates are used only within your organisation, minimizing exposure to external threats. Public PKI certificates are publicly verifiable, which is necessary for public services but increases potential risks.
  • Use Cases: Private PKI is ideal for securing internal systems, like VPNs, intranets, or IoT ecosystems. Public PKI is suited for external services, such as e-commerce websites or public APIs.
  • Scalability: Private PKI scales to meet your organisation's unique requirements, while Public PKI scalability depends on Public CA certificate pricing and policies.

Why are Public PKI CAs and their issued certificates trusted publicly?

Public Certificate Authorities (CAs) like DigiCert, Let’s Encrypt, or GlobalSign are trusted because they adhere to strict industry standards set by organisations like the CA/Browser Forum and the WebTrust program. These standards ensure that CAs follow rigorous processes for verifying the identity of certificate applicants, maintaining secure infrastructure, and issuing certificates with strong cryptographic standards. Public CAs’ root certificates are embedded in the trust stores of major browsers, operating systems, and devices (e.g., Mozilla, Microsoft, Apple), enabling universal trust. For example, when a browser encounters an SSL/TLS certificate issued by a trusted public CA, it verifies the certificate’s authenticity against the CA’s root certificate, ensuring secure communication. This widespread trust makes Public PKI certificates ideal for public-facing services like websites, where universal verification is essential. 

Why are Private PKI CAs and their issued certificates important?

Private PKI CAs are equally critical as they adhere to strict, organisation-specific security and compliance standards, ensuring robust protection for internal systems. Unlike public CAs, private CAs are managed internally, allowing organisations to enforce rigorous identity verification, certificate issuance, and lifecycle management processes tailored to their unique needs. For example, a Private PKI CA might issue certificates for employee devices with strict policies on key length and expiration to meet regulatory requirements. These certificates are trusted within the organization’s ecosystem because they are issued by a controlled, internal CA, reducing reliance on external entities and minimizing risks of external breaches or misissuance. Private PKI is vital for organizations requiring high security and privacy for internal operations, such as securing IoT devices, internal APIs, or sensitive data exchanges. 

Can you manage public certificates?

Yes, our Certificate Lifecycle Management (CLM) features, included in our Starter Bundle, allow you to manage both private and public certificates efficiently. Our CLM tools automate certificate discovery, monitoring, renewal, and revocation, reducing the risk of outages due to expired certificates. With a centralised dashboard, you gain visibility into all certificates—whether issued by a private PKI or external public CAs—complete with detailed reporting and impending expiry notifications. For example, you can track and renew a public SSL/TLS certificate alongside internal certificates, ensuring seamless operations. 

Do you offer public PKI services?

We focus exclusively on Private PKI solutions and comprehensive CLM for managing both private and public certificates. We do not issue public certificates, such as SSL/TLS certificates for public websites.  

How does your CLM enhance certificate management?

Our CLM, part of our Starter Bundle, simplifies the management of all your certificates. Key features include: 

  • Automation: Automatically discover and track certificates across your infrastructure, reducing manual errors.
  • Centralised management: Monitor both private and public certificates from a single platform, with real-time insights into certificate status and expiration.
  • Compliance and security: Ensure compliance with industry standards (e.g., ISO 27001) by maintaining secure, up-to-date certificate inventories. 
  • Proactive alerts: Receive notifications about impending expirations or vulnerabilities, preventing costly disruptions.

For example, a business using our CLM can manage internal certificates for employee devices while simultaneously ensuring a public website certificate from a CA like Let’s Encrypt is renewed on time. 

How can I get started with Private PKI and CLM

Get started on your own with our self-service journey! Sign up for a free trial of SecureSME's Starter Bundle to explore our Private PKI and CLM features hands-on. Set up your Private PKI for internal systems or use our CLM tools to manage both private and public certificates, all through an intuitive platform. Visit our Training Centre for step-by-step guides, tutorials, and best practices to help you customise and optimise your PKI and CLM set up.