What Is a Certificate Authority? Certification Authorities Explained

Certificate Authority (CA) – An overview of who they are and how they help in web security.

When visiting a website, the first thing we do is check whether it is secure, i.e. whether the padlock is there on the address bar. Businesses are also using various safeguards due to several successful data breaches by hackers. A study has shown that around 36 billion records were exposed through data breaches in the first half of 2020.

The alarming increase in the number of data breaches has also ensured growth in the global information security market. It is expected to reach US$ 170.4 billion in 2022. Increased use of SSL certificates helps websites have the first line of defense against hackers. Certificate Authorities issue them after validation based on the type of certificate chosen by the business.

What Is a Certificate Authority?

The Certificate Authority is a renowned and trusted organization that validates websites for a safer internet. The visitors can also understand that they are visiting secure websites. The Certificate Authorities help make the digital world safer, focusing on keeping the internet as safe as possible.

Aren’t you worried if you cannot know whether you are connected to a genuine website? Visitors to a website must understand that they are at the site they intended to visit. It can be possible only if a third-party verify the organization associated with the site. This is where the Certificate Authority comes to your help!

They provide the certificates only after verification, and the digital certificates contain information about the entity that owns the site. Visitors to the site can quickly check the antecedents of the certificate and also whether it is valid. The CA can also revoke an issued certificate if it is no longer considered trustworthy. There is a public revocation list that visitors can check before entering a website.

What are Private Certificate Authorities?

A private Certificate Authority is controlled by organizations for whom they provide the certificates. It is something like signing your official documents that show your identity. It can work within the organization, but not with third-parties. These certificates are ideal for internal networks and intranets, VPNs, closed user-groups, private email signing certificates, etc.

How does a Certificate Authority Work?

The websites undergo a verification process undertaken by the Certificate Authorities. The severity depends on the type of certificate chosen by the business. The certificate can prove the authenticity of the website to whoever wants it.

The Certificate Authority is part of a more extensive process called the Public Key Infrastructure (or PKI). First, the CSR is generated with a private key and then the applicant/requestor completes the configuration process and validates the domain. The CA checks whether the documentation provided by the certificate requestor is authentic. If the documentation is in order, the certificate is issued.

They must assess whether the information provided in the CSR is accurate. If found to be true, they issue the certificate and sign it with the private key. The business can use the certificate for HTTPS during web access.

A digital signature ensures that the certificate is valid, and a secure connection is established between the web server and the visitor’s browser. When the business receives the certificate, it must be installed on the webserver. The installation may vary across various such authorities. The public key helps to encrypt the communication, while the private key decrypts the data.

The SSL certificate issued by the Certificate Authority helps you to use a secure TLS protocol to exchange encrypted data. The certification helps verify the website’s identity and the business and ensures encrypted information exchange with the visitors’ browsers. Companies can protect the data exchanged with the visitor and prevent any possible man-in-the-middle attacks by hackers.

What is a Digital Certificate, and what does it do?

A digital certificate consists of files that can associate a pair of cryptographic keys with websites or an organization. They can also be assumed to be an electronic password that can secure data exchange over the internet using the Public Key Infrastructure (PKI) technology. The technology ensures secure communication over the internet.

The key pair consists of a public-private key. The private key is kept secure, and the public key is within the certificate. The private key can be used by authorized personnel in the business to sign the documents. The public key is used to assess the validity of the signatures.

The format of these certificates is based on the X.509 standard. It consists of the digital signature, public key and documents establishing the identity of the entity. The information of the certificate authority is also mentioned. The issued certificate can be used for code signing, authentication for websites, document signing, etc.

Types of Digital Certificates

We will have a glimpse at the certificates that a Certificate Authority provides.

SSL/TLS Certificates

These certificates ensure an encrypted communication channel is established between a visitor’s browser and the webserver. The “Not Secure” warnings are also removed as the website now works using the HTTPS protocol. Again, there are different types of certificates based on functionalities.

Single Domain Certificates – They secure an individual domain, including the www and non-www websites.

Wildcard SSL Certificates – They secure an unlimited number of first-level sub-domains, along with the primary domain, under a single certificate.

Multi-domain SSL certificates – They allow you to secure multiple domain names and SAN domains through a single certificate.

Multi-domain wildcard certificates – These versatile certificates allow you to secure multiple domains along with several sub-domains.

Code Signing Certificates

Software developers need these certificates to sign the underlying code digitally to ensure the integrity of the software. Users can be assured that the software they are trying to download has not been tampered with by any unauthorized third-party. Here is a guide to understanding what is code signing certificate.

Email Signing Certificates

These specialized certificates help to validate clients and individuals with web servers. An email signing certificate or S/MIME certificate makes it possible for users to digitally sign their emails and encrypt their data at rest including text and attachments as well as ensuring that only the intended recipient is able to decrypt the contents of the mail.

Document Signing Certificates

These certificates help to establish the integrity of the document while authenticating the creator as well.

Why Do We Need Certificate Authorities?

How can you ensure that visitors trust your website? Only if they are certified to be safe by third-parties. The Certificate Authority can provide credibility for a website! The publicly trusted CAs act as autonomous entities. Any requestor of digital certificates does not control them.

How does a Certificate Authority become trusted?

Are you aware that the Certificate Authorities need to abide by minimum standards? The CA/Browser Forum requires them to abide by basic guidelines. The certificates that are provided cannot be forged by any third-party. There is a process of vetting your entity and it can confirm to browsers, operating systems and email clients that your site is authentic.

Some browsers and operating systems have their own set of guidelines that a Certificate Authority must consider. Some of them also require the Certification Authorities to undertake regular audits to ensure adherence to the laid down guidelines. Users can check whether the Certificate Authority is a member of the CA/Browser Forum.

The X.509 standards state that the authorities must act truthfully and reliably in managing the issuance of certificates. They will also be bound to comply with the published certification practice statement. There must also be underlying trust in the relationship between the Certificate Authority and an authenticating entity.

Certificate Authority Validation Levels

The verification process for a website starts with a business approaching the Certificate Authority for obtaining an SSL certificate. The procedure to be followed depends on the type of certification required.

Domain Validation

Domain Validation is the minimum security level that your website needs to use the HTTPS protocol. The authority checks whether the business that has applied for the certificate is the owner of the website. The certificate can be issued within a few minutes.

Organization Validation

Through organization validation, the Certificate Authorities go a step further and perform a basic assessment of the company. A human element gets involved in reviewing the documentation provided by the business. Additional information about the business is also researched before the certificate is issued.

Extended Validation

It is the holistic validation that is undertaken. An exhaustive assessment of the organization is carried out. The validation procedure is more rigorous than that followed during organization validation. Learn more about what is extended validation certificate.

List of Trusted Certificate Authorites

Devices and browsers trust several Certificate Authorities. One factor to be considered is the number of years in operation. While the certificates are compatible with almost 99% of browsers, it is better if they are backward compatible too. We will provide an overview of some of the trusted ones here.

#1. DigiCert

DigiCert is a renowned brand in PKI, SSL and IoT solutions and was founded in 2003. They had also won the Frost & Sullivan Global TLS Certificate Company of the Year in 2020.

The brand offers SSL certificates with the latest technology and supports 2048-bit public key encryption (3072-bit and 4096-bit are available too). The products also support the RSA public-key SHA-2 algorithm and ECC public-key cryptography.

#2. RapidSSL

A subsidiary of GeoTrust Inc, RapidSSL is a trusted Certificate Authority that came into existence in the year 2003. Renowned for low-cost and fast issuance of standard and wildcard SSL certificates, it is endowed with the latest encryption standards and modern infrastructure.

It offers 256-bit encryption and 99.9% browser compatibility. The perfect choice for your brand is a well-respected symbol of trust.

#3. GeoTrust

GeoTrust was the pioneer CA to initiate domain-validated certificates which today dominate cyberspace. Bought by Symantec from Verisign in the year 2010, it has lived up to its pioneering status.

It offers unbeatable 256-bit encryption, SHA2 and ECC support, and free unlimited re-issuance during the certificate lifespan amongst other benefits. Its low-cost SSL options are a boon for business owners who seek to strengthen their security and improve SERP rankings.

#4. Thawte

Established in the year 1995, in South Africa, it has now spread roots globally and has issued 945,000+ certificates. It gives you a whole host of benefits which include, unlimited server licenses, free Thawte trusted site seal, complete business authentication and more at unbelievably low prices!

#5. Comodo

Comodo provides internet security solutions that freelancers can use for their blog sites and e-commerce brands alike. The products offer 256-bit encryption, licenses for unlimited servers and comprehensive customer support.

The brand is also recognized for its world-class client support and innovative products.

The brand provides an entire range of TLS certificates and has provided over 100 million such certificates.

What Is the Role of a Certificate Authority in Public Key Infrastructure?

The PKI is the framework consisting of the procedures and technologies that form the basics of web security. The X.509 defines PKI as the infrastructure that supports how the public and private keys are managed to ensure encryption and authentication of services. It helps entities transmit data using encryption; else, it would be easy for hackers to have unlawful access to sensitive information.

The Certificate Authority is a pillar of PKI technology. If you remove them, you will only have a voluminous group of unverified digital certificates. It will be easy for hackers to impersonate ownership of a site and steal essential information. They can help by authenticating websites and businesses with substantial operations in place that allow them to verify identities and issue proper digital certificates.

The Certificate Authorities follow stringent guidelines laid down by the browsers and maintain best practices to ensure web security. It is the reason that they are trusted by browsers that make the management of the digital certificates issued by them easier.


There has been a manifold increase in the number of cyberattacks against businesses. Businesses must be careful and put in place rigorous processes that will prevent such attacks. It becomes necessary that a third-party assess the websites that can engender a sense of trust in the visitor’s minds.

A Certificate Authority does that for you! It validates entities and issues digital certificates to facilitate encryption. As cybercrime increases, installing an SSL certificate is the line of defense you can create against such attacks.


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