When you visit a website, the information that you share, such as your personal or financial data, needs to be kept private and secure. That's where Secure Socket Layer (SSL) certificates come in. These certificates are an essential component of online security and are necessary to establish a secure connection between a website and its visitors. In this article, we will discuss the importance of SSL certificates, how they work, the different types available, the difference between SSL and its successor, Transport Layer Security (TLS), and the various ways to obtain an SSL certificate.
Why do you need an SSL certificate?
An SSL certificate is necessary to establish a secure connection between a website and its visitors. This is particularly important when sensitive information, such as personal or financial data, is exchanged. Without an SSL certificate, this information can be intercepted and read by third parties (attackers), leading to potential fraud or identity theft. In addition, many modern web browsers will display a warning message when attempting to access a website without an SSL certificate, which can damage the trust of the website's visitors.
Understanding how SSL certificates work
An SSL certificate works by creating an encrypted connection between a website's server and the visitor's web browser. When a visitor accesses a website with an SSL certificate, their browser verifies the certificate's authenticity and establishes an encrypted connection. This encrypted connection ensures that any information exchanged between the website and the visitor is kept private and secure.
Under the hood the browser verifies that the certificate provided by the website:
Is valid for the same domain as the one being accessed.
Is been issued by a trusted CA (Certificate Authority).
Is valid and has not passed its expiration date.
Once the user's browser has verified the validity of the SSL certification, the connection continues to be secure. If not, you will get a “not secure” warning in your browser, or it will deny access to the site. If successful, the browser and website server exchange the necessary details to form a secure connection and the site loads.
What are the different kinds of SSL?
There are several different types of SSL certificates available, each with varying levels of security and validation. They include
Domain Validated (DV) Certificates
This is the most basic type of SSL certificate and only verifies the ownership of the domain. The certificate authority (CA) will check that the person requesting the certificate has the authority to request it for the domain. Once the domain ownership is verified, the CA will issue the certificate. DV certificates are typically the quickest and easiest to obtain, but they offer the lowest level of trust and security.
Organization Validated (OV) Certificates
OV certificates provide a higher level of validation than DV certificates. In addition to verifying the ownership of the domain, the CA will also verify the organization behind the domain. This includes checking the organization's legal existence, address, and phone number. OV certificates take a bit longer to obtain than DV certificates, but they offer a higher level of trust and security.
Extended Validation (EV) Certificates
EV certificates offer the highest level of validation and trust. In addition to verifying the ownership of the domain and the organization behind the domain, the CA will also conduct a rigorous vetting process to verify the organization's identity. This process includes checking government-issued documentation, conducting background checks on the organization's officers, and physically verifying the organization's address. EV certificates can take several days to a couple of weeks to obtain, but they offer the highest level of trust and security.
A Wildcard certificate is a type of certificate that allows the certificate holder to secure any subdomains under a single domain name. For example, if you own the domain "example.com" and have a wildcard certificate, you can secure "sub1.example.com", "sub2.example.com", "sub3.example.com" etc. with a single certificate. It can be a cost-effective solution for organizations that have multiple subdomains and want to secure them all with a single certificate.
Multi-Domain Certificates (SAN)
Multi-Domain Certificates (SAN) are also called “Subject Alternative Name” (SAN) certificates. It allows the certificate holder to secure multiple domain names with a single certificate. For example, if you own the domains "example.com" and "example.net," you can secure both of them with a single SAN certificate.
Self-signed certificates are issued by the entity that runs the server rather than a trusted third-party CA. These types of certificates are suitable for internal use and testing, but they are not recommended for public-facing websites because they are not trusted by web browsers and may generate security warnings for visitors.
It's important to note that, depending on the level of security and trust you need, you should choose the appropriate type of SSL certificate for your website
What is TLS and how does it differ from SSL?
Transport Layer Security (TLS) is the successor to SSL and is considered to be more secure. Both SSL and TLS are cryptographic protocols that provide secure communication over the internet, but TLS has several key differences. One of the main differences is that TLS uses a stronger encryption algorithm, making it more difficult for third parties to intercept and read the information exchanged between a website and its visitors. Additionally, TLS requires the use of a certificate for server identification, which is not required for SSL.
Different ways one can obtain an SSL certificate
There are several ways to obtain an SSL certificate, including purchasing one from a reputable certificate authority (CA) such as DigiCert, GlobalSign, or Comodo, or using a free certificate from Let's Encrypt. Additionally, some web hosting providers may offer SSL certificates as part of their hosting packages.
SSL certificates are a vital component of online security, ensuring that sensitive information exchanged between a website and its visitors is kept private and secure. There are various types of SSL certificates available, each with varying levels of security and validation. Its successor, TLS, provides a stronger encryption algorithm and requires a certificate for server identification. Obtaining an SSL certificate can be done by purchasing it from a reputable certificate authority, using a free certificate, or using one that some web hosting providers offer as part of their hosting package.