What is an SSL Certificate and Where it is Used

What is an SSL Certificate

An SSL (Secure Sockets Layer) Certificate is a digital security certificate.

It enables encryption of sensitive information from a web server to a browser.

It provides authentication to the user to confirm the identity of the website, and also offers encryption to protect data from being intercepted by hackers.

How Do SSL Certificates Work

SSL certificates work by establishing a secured connection between a server and a client.

This secure connection is initiated by the server and the client must first establish an SSL handshake, an exchange of private and public encryption keys.

This handshake is used to authenticate and secure the connection between the two, ensuring that the data transfered between them is private and encrypted.

Once the secure connection is established, the client and the server can safely exchange sensitive data and information.

Differences Between SSL and TLS

SSL and TLS are both encryption protocols used to secure web data, but there are some key differences between them:

SSL is an older protocol developed in 1995 while TLS is an updated version of SSL developed in 1999.

SSL uses a 40-bit encryption key while TLS uses a 128-bit encryption key and can have extended encryption keys with up to 256 bits.

TLS provides additional security features not provided in SSL, such as Perfect Forward Secrecy which ensures that all past communications are safe even if a key is compromised.

TLS protocol is more secure and less prone to cyber-attack compared to SSL.

TLS protocol is largely accepted and almost universally used on the web today, while SSL is still supported but being phased out.

Types of SSL Certificates

There are several types of SSL certificates –

Domain Validation (DV) SSL certificate: Confirms a website is registered, active, and Secure.

It confirms the domain name has not expired and has been registered with a legitimate third-party organisation.

Organisation Validation (OV) SSL Certificate: An OV SSL Certificate requires additional information to validate the authenticate the owner.

In addition to the information, additional steps such as validation of the business documentation and phone verification may be required.

Extended Validation (EV) SSL Certificate: It requires much more in-depth validation of the website, the organisation and its owner to a greater extent than an OV certificate.

It provides the highest level of confidence in the identity of your website.

Wildcard SSL Certificate: A wildcard SSL certificate is valid for all the sub-domains that belong to the main domain.

For instance, if a user is clients.example.com and the main domain is example.com, the wildcard certificate could be used for both websites.

Multi-domain SSL Certificate: A multi-domain SSL certificate is a single certificate that supports multiple domains.

This type of certificate increases the security of multiple websites that use the same server and certificate.

Unified Communications Certificate (UCC SSL): It is used for Microsoft Exchange and Office Communications Server.

A UCC SSL certificate can secure multiple domains and host names that are used by Microsoft applications.

How to Install an SSL Certificate

To install an SSL Certificate, you will typically require roots access to your server. You can then login to the server using your login credentials through a command line and execute the required commands.

The instruction for install SSL Certificate will vary depending on the type of certificate and the server you are using, but there are a few steps common.

The steps to install an SSL Certificate –

Generate CSR: First, you need to generate a Certificate Signing Request (CSR) and private key pair on the server you will use to install the SSL certificate.

Use the CSR to purchase the certificate from a Certificate Authority (CA).

Activate the Certificate: After purchasing the certificate from a CA, you will need to activate it (example – via email validation, domain control validation or another process).

Download the Certificate: After the certificate is issued, you will need to download the necessary certificates that are provided in the CA’s control panel.

Install the Certificate: Next upload the key file and issued certificates to the server.

Depending on what type of server you have, the installation instructions will vary.

Test & Troubleshoot: Once the certificate is installed, you need to confirm it is working correctly.

This can be done by testing your website using a browser, tool or services provided by an SSL certificate issuer.

If any errors occur, you will have to troubleshoot to resolve them.

Renewal: Eventually the SSL certificate will need to be renewed.

The deadline for renewing a certificate will depend on the certificate you purchased.

You can also ask the hosting support to install the SSL Certificate on your behalf if you do not want to add it yourself.

Typically most hosting providers will do it for you.

How to Generate a CSR

Generating a CSR (Certificate Signing Request) involves creating a key pair for your server.

Download and install an SSL key creation tool on your server. Popular SSL key creation tools include OpenSSL and Keybot.

Using the installed SSL key creation tool, generate a key pair for your server.

Once you have generated the key pair, use the tool to generate a Certificate Signing Request (CSR).

The CSR will contain information about your server and any other associated domain names that you want to secure with the SSL certificate.

Once you have generated the CSR, submit it to a Certificate Authority (CA) to request an SSL certificate.

The CA will then use the CSR to generate an SSL certificate.

Once generated, you can install the certificate on your server.

What Happens After Your Install SSL Certificate

When you install or get installed an SSL certificate on a website, the website can be accessed through https protocol on the browser address bar.

The https protocol will show a lock sign before it, which means the SSL certificate is working properly.

Benefits of Using SSL/TLS

There are several benefits to using an SSL Certificate –

Increased Security: Provides an encrypted connection between two devices. This encryption helps protect the data in transit from being intercepted and read by malicious entities.

Data Integrity: Ensures that the data received from the server is from the expected source and is not tampered with in transit.

Authentication: Lets the website owner prove their identity to the visitor.

This authentication helps protect against phishing attacks and man-in-the-middle attacks, ensuring the user is accessing a legitimate source.

Improved SEO: Google now uses SSL as a ranking signal, and websites with SSL/TLS installed have better visibility in search results than those without.

Increased User Confidence: Knowing that the connection is secure, your users will feel more confident in conducting transactions on your website.


SSL/TLS is going to be the norm in future. All websites should be using a SSL/TLS certificate if they are not using one already.