What Is an SSL Certificate: Your Ultimate Guide
Have you ever seen a padlock icon together with the URL of the website you’re visiting? We’re sure that you have. But do you know what the padlock icon signifies? It signifies that the website you’re visiting is protected by an SSL certificate.
Now, you’re probably thinking things like what is an SSL certificate or how does an SSL certificate work. To help you get answers to these and other questions, we’ve created this ultimate guide. After reading this piece, you should have a clear idea of all things related to SSL certificates.
So, let’s get started.
What Is an SSL Certificate?
SSL is the abbreviation for “Secure Sockets Layer,” which is a security protocol that establishes an encrypted connection between a web browser and a web server.
SSL protocol was first introduced in 1994 by Netscape. The objective was to secure online transactions made using their Navigator browser.
Basically, an SSL certificate refers to a digital certificate that acts as an authentication of the identity of a website. Companies and businesses that want to enable this encrypted connection need to add an SSL certificate to their websites so that they can keep their customers’ information secure and private. Websites with SSL certificates also facilitate secure online transactions.
These days, SSL certificates are commonly used to secure data transfer, logins, online transactions, and browsing of social media platforms. SSL helps to maintain secure Internet connections and protects information, which is being transferred between two systems, from being read or modified by criminals.
When a web server is equipped with an SSL certificate, the HTTPS protocol and the padlock get activated and secure connections from the server to a browser are created.
An SSL certificate binds several things together. These include:
- An organizational identity (such as the company’s name) and location
- A domain name, hostname, or server name
A business or organization can initiate secure sessions between its web server and browsers by adding an SSL certificate to its server.
When an SSL certificate is properly installed on a web server, the application protocol (commonly known as HTTP) becomes HTTPS. Here, the “S” refers to “secure.”
Although once there were multiple versions of SSL protocol available, all of them experienced security hazards at some point. However, these days, we use a more secure, advanced version of SSL, which is known as TLS or “Transport Layer Security.”
When you buy an SSL certificate, you actually buy a TLS certificate. Since SSL is a more widely used term, sellers still refer to the certificates as SSL certificates.
How Does an SSL Certificate Work?
Now that you’ve got a clear idea of what is an SSL certificate, let’s try to understand how does an SSL certificate work?
The key objective of using an SSL certificate is to ensure that all data transferred between two systems, or between websites and users, cannot be read by any means. An SSL certificate achieves this through the use of public key cryptography.
Two long strings (known as keys) of random numbers are mainly used in this specific kind of cryptography. One key is called a public key and the other one is known as a private key.
The server remains aware of the public key and it can be found in the public domain. Any message can be encrypted using a public key. Let’s consider an example to get a clear understanding of the roles of these keys.
A sends a message to B and locks it using the public key of B. However, if anybody wants to decrypt that message, they must have the private key of B. Since B is the only person who has this private key, B can only unlock A’s message.
If the message is intercepted by a hacker before it gets unlocked by B, they get nothing but a cryptographic code that cannot be broken by any means.
Here’s the working method of the process.
- A server or browser tries to connect to a web server (i.e. a website) that has an SSL certificate.
- The server or browser requests that the web server proves its identity.
- In response, the web server sends the server or browser its SSL certificate’s copy.
- The server or browser verifies if the SSL certificate can be trusted. If it’s a yes, the web server receives a signal from the server or browser.
- Then a digitally signed acknowledgment is returned by the web server to begin a session encrypted by SSL.
- Encrypted data starts to flow between the web server and the server or browser.
Sometimes, this process is called an “SSL handshake.” Although it may seem to be a lengthy process, it actually occurs in milliseconds.
How to View the Details of an SSL Certificate?
As mentioned above, when an SSL certificate protects a website, a padlock icon becomes visible in its URL address bar. This provides an assurance and indicates trust to the site’s visitors.
You only need to click on the padlock icon to view the details of the SSL certificate. An SSL certificate typically includes the following details:
- The website name for which the SSL certificate was issued for
- The device, person, or organization to which it was issued to
- Name of the issuing Certificate Authority
- Digital signature of the Certificate Authority
- Subdomains associated with the main domain
- The date when the certificate was issued
- The date when the certificate will expire
- The public key while the private key remains hidden
Why Is an SSL Certificate Required?
So far, we’ve been discussing different aspects of an SSL certificate. Now, you’re probably thinking about the main thing, “why do I need an SSL certificate?”
SSL certificates help websites maintain the security of their user data, establish their ownership, protect them from having fake versions created by hackers, and build trust among their users.
For instance, if a website requires you to sign in, enter your personal details like your credit card number, or review your confidential information like your financial information or health benefits, then it has to maintain the confidentiality of your data.
If the site is secured with an SSL certificate, you can stay assured that it’s safe and authentic and you can share your personal information with it. An SSL certificate also guarantees that all your online interactions remain private.
We’ve already discussed that when an SSL certificate protects a website, the HTTP is shown as HTTPS. The majority of browsers display HTTP sites, which don’t have SSL certificates, as “not secure.” This clearly indicates that those sites may not be trustworthy. This also compels businesses that don’t have SSL certificates to buy them and become secure.
With an SSL certificate, you can secure the following types of information:
- Bank account information
- Details of credit card transactions
- Login credentials
- Personally identifiable information. These include your full name, address, contact number, date of birth, etc.
- Proprietary information
- Medical records
- Legal contracts and documents
What Are the Different Types of SSL Certificates?
After getting the answer to the question, “why do you need an SSL certificate,” the thought that should come to your mind is which type of SSL certificate you should buy.
You can choose from different types of SSL certificates based on the validation level you need. Mainly, six types of SSL certificates are available in the market. These include:
- EV SSL or Extended Validation certificates
- OV SSL or Organization Validated certificates
- DV SSL or Domain Validated certificates
- MDC or Multi-Domain SSL certificates
- UCC or Unified Communications certificates
- Wildcard SSL certificates
Let’s see what each of these entails.
EV SSL or Extended Validation Certificates
This is the costliest and highest-ranking type of SSL certificate. High-profile websites that facilitate online payments and collect personal information tend to use EV SSL certificates. When you install an EV SSL certificate, it displays HTTPS, the padlock, the name of your business, and your country on the address bar of the browser.
When your website displays your information on the address bar, your users can easily distinguish it from other harmful or fake sites. If you want to install an EV SSL certificate, you’ve to complete a standardized identity verification process to prove that you have legal authorization for the domain’s exclusive rights.
OV SSL or Organization Validated Certificates
These types of SSL certificates come with an assurance level similar to the Extended Validation certificates. This is because site owners must complete a thorough validation process to install an OV SSL certificate. If you install an OV SSL certificate, it displays your information on the browser’s address bar so that your users can distinguish it from malicious sites.
The primary objective of using an OV SSL certificate is to encrypt sensitive information of the user during transactions. This is also the second costliest type of SSL certificate (after EV SSL). If you run a public-facing or commercial website, it must be secured with an OV SSL certificate to make sure that information shared by your customers remains confidential.
DV SSL or Domain Validated Certificates
DV SSL certificates provide minimal encryption and a lower level of assurance. This is because if you want to install a DV SSL certificate, you need to complete a minimal validation process. This type of SSL certificate is ideal for information websites, blogs, or sites that don’t facilitate online transactions or collect personal information.
DV SSL certificates are the fastest to obtain and one of the cheapest ones. During the validation process, you only need to establish your domain ownership by responding to a phone call or email. Once installed, the browser address bar just displays the padlock icon and HTTPS without any business name or other details.
MDC or Multi-Domain SSL Certificates
If you want to secure multiple subdomains and/or domains, you can use a multi-domain SSL certificate. You may use a mix of completely unique subdomains with different Top-Level Domains (TLDs) except for internal/local ones and domains.
Some examples include:
It’s important to note that multi-domain SSL certificates don’t automatically support subdomains. If you want to secure both example.org and www.example.org using one multi-domain certificate, then you need to specify both hostnames when purchasing the certificate.
UCC or Unified Communications Certificates
These types of SSL certificates are also viewed as multi-domain SSL certificates. Unified Communications certificates were primarily designed to secure Live Communications and Microsoft Exchange servers.
These days, these certificates can be used to secure multiple domain names using a single SSL certificate. These are organizationally validated and after installation, they display a padlock icon on the browser. You can also use UCCs as EV SSL certificates so that your site visitors get the highest level of assurance by seeing the address bar.
Wildcard SSL Certificates
If securing a base domain along with unlimited subdomains using a single SSL certificate is your primary objective, you can use a Wildcard SSL certificate. Therefore, if you want to secure multiple subdomains, then purchasing a single Wildcard SSL certificate will be less expensive than purchasing individual SSL certificates to secure each of them.
Wildcard SSL certificates display an asterisk sign (*) to signify the common name. Here, the asterisk sign represents all valid subdomains that come under the same base domain. For instance, you can use a single Wildcard SSL certificate to secure the following subdomains:
Before purchasing an SSL certificate, be sure to get familiar with all these types of SSL certificates to make an informed decision.
Considering the increasing number of cyberattacks, it has become a must to secure your site using an appropriate SSL certificate. Now that you know what is an SSL certificate, how does an SSL certificate work, why you need an SSL certificate, and the different types of SSL certificates, go ahead and start securing your site right away.