Private PKI vs PKIaaS: which model to choose?
September 19, 2025 | Jordi Genescà Prat
SSL Enterprise
Public Key Infrastructure (PKI) is essential to ensure digital security: it encrypts communications, authenticates identities, and protects sensitive data. But when a company must decide how to implement it, a dilemma arises: manage a private PKI or rely on an externalized solution such as PKI as a Service (PKIaaS)?
In this article, we explore the differences between both models, their pros and cons, and which organizations benefit most from each approach.
What is a private PKI?
A private PKI is an infrastructure fully managed by the organization. It involves setting up servers, configuring software, generating and issuing digital certificates, and maintaining the entire system.
While it offers full control, it also requires a high level of technical, operational, and legal responsibility.
What is PKI as a Service?
PKIaaS outsources all infrastructure management to a specialized provider. The company uses PKI services via an API or cloud platform, without having to worry about internal maintenance, scalability, or security.
This allows for fast, automated certificate issuance aligned with best security practices, even without in-house experts.
Quick comparison
- Control and customization:
a private PKI offers maximum control over policies, trust roots, and architecture. PKIaaS follows a standardized and secure framework, but with less flexibility. - Initial cost:
implementing a private PKI usually requires a higher upfront investment. PKIaaS is subscription-based with lower initial costs. - Deployment time:
PKIaaS enables certificate issuance within minutes. A private PKI may take weeks to become fully operational. - Management and maintenance:
private PKIs require dedicated teams and constant monitoring. PKIaaS drastically reduces the operational workload. - Regulatory compliance:
PKIaaS providers often offer certified infrastructure and audits that help meet regulations such as eIDAS, GDPR, ISO 27001, etc.
When is a private PKI the best choice?
This option is recommended for large organizations with specific security needs, extensive legacy systems, or regulatory constraints requiring full control over keys and processes—such as governmental or military environments.
When is PKIaaS more suitable?
PKI as a Service is ideal for businesses that prioritize agility, scalability, and security without the complexity of managing infrastructure. Startups, SMEs, and enterprises undergoing fast-paced digital transformation benefit the most from this model.
It's also highly effective in supporting encryption, authentication, and digital signature in cloud, SaaS, and remote work environments.
Conclusion
Choosing between private PKI and PKIaaS depends on your technical capacity, security strategy, and business goals. Both options can coexist or evolve over time.
The important thing is to deploy a PKI solution aligned with your company's current and future cybersecurity needs.
