Most Popular Certificate Authorities

This section provides a list of most popular certificate authorities.

Based on the Website monitoring report provided, top 12 CA (Certificate Authorities) in 2018 are:

CA               Share

IdenTrust        45.5%
Comodo           31.3%
DigiCert Group   11.0%
GoDaddy Group     6.9%
GlobalSign        3.1%
Certum            0.8%
Actalis           0.4%
Entrust           0.3%
Secom Trust       0.3%
Let's Encrypt     0.2%
Trustwave         0.1%
WISeKey Group     0.1%

Based on a research report from, top 30 certificate authorities in 2009 were:

 Share   Group                Certificate Authority

21.17%   Go Daddy   , Inc.
12.79%   VeriSign             Equifax Secure Inc.
11.19%   VeriSign             Thawte Consulting cc
10.58%   Comodo               UTN-USERFirst-Hardware
 8.23%   VeriSign             VeriSign, Inc.
 7.80%   VeriSign             Equifax
 6.38%   VeriSign             VeriSign Trust Network
 3.37%   Comodo               Comodo CA Limited
 2.55%   Network  Solutions   Network Solutions L.L.C.
 2.25%   Go Daddy             Starfield Technologies, Inc.
 1.57%                        DigiCert Inc
 1.24%   GlobalSign           GlobalSign nv-sa
 0.67%                        Cybertrust
 0.63%   AmbironTrustWave     SecureTrust Corporation
 0.60%   VeriSign             Thawte Consulting (Pty) Ltd.
 0.56%                        Root CA
 0.55%                        IPS Certification Authority s.l.
 0.47%   Comodo               Secure Business Services, Inc.
 0.42%   VeriSign             RSA Data Security, Inc.
 0.34%                        Betrusted Japan Co., Ltd.
 0.33%                        StartCom Ltd.
 0.30%                        SECOM
 0.27%   GlobalSign           Alpha
 0.25%   GlobalSign           GlobalSign
 0.24%                        TC TrustCenter for Security in Data ...
 0.23%                        CAcert Inc.
 0.20%   Comodo               Comodo Limited
 0.19%                        T-Systems Enterprise Services GmbH
 0.19%                        U.S. Government
 3.11%                        (Others)

Table of Contents

 About This Book

Introduction of PKI (Public Key Infrastructure)

 What Is PKI (Public Key Infrastructure)

 Usage Examples of Public Key Infrastructure

Most Popular Certificate Authorities

 Introduction of HTTPS (Hypertext Transfer Protocol Secure)

 Using HTTPS with Google Chrome

 Using HTTPS with Mozilla Firefox

 HTTPS with Microsoft Edge

 Using HTTPS with Apple Safari

 HTTPS with IE (Internet Explorer)

 Android and Server Certificate

 iPhone and Server Certificate

 Windows Certificate Stores and Console

 RDP (Remote Desktop Protocol) and Server Certificate

 macOS Certificate Stores and Keychain Access

 Perl Scripts Communicating with HTTPS Servers

 PHP Scripts Communicating with HTTPS Servers

 Java Programs Communicating with HTTPS Servers

 .NET Programs Communicating with HTTPS Servers - Root CA Offering Free Certificates

 PKI CA Administration - Issuing Certificates

 Comodo Free Personal Certificate

 Digital Signature - Microsoft Word

 Digital Signature - 3

 S/MIME and Email Security

 PKI (Public Key Infrastructure) Terminology

 Outdated Tutorials


 Full Version in PDF/EPUB