Gartner Research

Public Key Infrastructure Concepts and Architecture

Published: 11 March 2011

ID: G00210023

Analyst(s): Robin Wilton


Over the last decade, the technology of public key infrastructure (PKI) has remained surprisingly stable while its adoption has persistently confounded forecasts and challenged initial assumptions. This assessment looks at what has remained the same, what has changed, and what has evolved in unexpected ways. It offers an analysis of why PKI reality has so often diverged from expectations and how organizations should view PKI as an enterprise risk mitigation tool in future deployments.

Table Of Contents

Summary of Findings


  • The Evolution of PKI Since 2000
  • Elements of an Enterprise PKI
  • Fundamental Principles of PKI
  • Asymmetry of Key Usage
  • Authentication of the Public Key
  • Further Evolutionary Factors
    • Key Rings and Credentials
  • Innovation in PKI
  • Trust Models
    • Technical Interoperability
    • Certificate-Level Interoperability
    • Authentication-Level Interoperability
    • Contractual and Regulatory Interoperability
  • Registration Authorities and Trust
    • The Role of Policies and Practice Statements in Defining RAs and CAs
    • Regulatory Frameworks for Relying on PKI-Based Services
  • Strengths
  • Weaknesses

The Details

  • Certificates
    • Certificate Classes
  • Certificate Authorities
    • Registration Authorities
    • Issuing Certificates
  • Certificate Revocation and Status Checking
    • Certificate Revocation Lists
  • PKI Repositories: Databases and Directories
    • Directory Requirements
    • Directories, PKI, and Naming Models
    • Enterprise Directory
  • Trust Models
    • Cross-Certification
    • Certificate Hierarchies
    • More Flexible Trust Models
    • Communities of Interest and Hybrid Trust Models
    • The Hybrid Reality
    • The Pragmatic Reality
    • Putting It Together
  • Key Management (Summary)
    • Key Life Cycles
    • Recovery of Encrypted Data
    • The Tension Between Accountability and Key Recovery
    • Key Separation and User Key Rings
    • Revocation
    • Key Management: Interim Summary
  • Key Management (Details)
    • Key Generation
    • Private Key Storage and Roaming
    • Key Backup and Recovery
    • Key Escrow
    • Key Update
    • PKI Key Management: The Ultimate Irony
  • PKI Policies
    • Certificate Policies
    • Certificate Practice Statements

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