How Does SSL Work - Everything You Want to Know

Deyan Georgiev
Deyan Georgiev

Updated · Feb 07, 2023


Techjury is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more.

SSL – Secure Sockets Layer is a protocol for establishing authenticated and encrypted links. 

Nowadays, it finds most of its application in securing credit card transactions, login details, and all sorts of data transfers. 

Spotting the SSL padlock next to a domain name is also a good sign that the site you’re visiting is legitimate.

But, how does SSL work? Are there different types of it?

Let’s find out!

How Does SSL Work?

The SSL protocol provides encrypted online communication. It ensures it by a pair of keys – private and public. The public key is widely distributed, but the private one is kept secret. The former allows message encryption, while the latter provides decryption.

The HTTPS protocol is a prime example of SSL in action. It encrypts the data exchange between the website and the device. Even if the process is interrupted halfway, it cannot be deciphered by third parties.

SSL security not only keeps data exchange safe but also protects users from scams. You can consider only SSL-certified sites authentic. All big web platforms have an SSL certificate. If they don’t, there’s a high chance the site you’re visiting is a phishing copy of the original.

It’s worth mentioning that although the term SSL is still widely used, the technology is now replaced by an upgraded version called TLS (Transport Layer Security).

The SSL\TLS Handshake

The handshake is the process of negotiations between your device and the SSL secured server. The two sides decide on the SSL/TLS version and type of encryption used. Then, they exchange authentication data and establish a secured SSL connection.

In most cases, the authentication data exchange is one-sided – only the client authenticates the server. A mutually-authenticated handshake is when both sides confirm their identities. This is a requirement for government institutions, bank transfers, and other situations where both sides must be known.

Each connection through the SSL layer forms an individual session. During each one, the negotiated terms of communication differ. Steps may be removed or added, as is the case with two-way authentication. 

Types of SSL Certificates

SSL certificates prove that a connection is secured. They also provide information on the site’s authenticity, its owner, the public key used, and the certificate’s issuer. The major difference between the available certificates is the amount of information needed to apply for it.

Domain Validation (DV) Certificates

The Domain Validation Certificate is the most common and easiest to issue SSL cert. That’s because the validation takes place on the domain and can be completely automated. The certificate provides HTTPS communication and strong encryption for a single domain.

Organization Validation (OV) Certificates

If you’re the owner of an online business that collects sensitive information, you need the Organization Validation certificate. This includes shops, delivery companies, financial institutions, social media networks, etc.

The OV certificate offers the same functions as the DV one. It also adds the name of the organization in the site seal. OV certificates are often paired with wildcard and multi-domain features to add value to the package.

Extended Validation (EV) Certificates

The Extended Validation is the highest and most difficult to issue SSL cert available. To receive it, the domain holder must prove their identity, right to use the domain, and the physical location of their organization, among other documents.

The benefit of passing through this difficult process is increased security for your users. The chances of a site with an EV certificate being a phishing scam are close to zero.

Wildcard SSL Certificates

A domain may hold multiple subdomains, and you’ll need to provide certificates for all of them. The wildcard certificate is issued on the main domain and usually contains an asterisk character (*) in its field name. The symbol indicates that all subdomains are also SSL/TLS entrusted.

Multi-Domain SSL Certificates

A multi-domain website certificate also offers subdomain validation but allows for the certification of a few domains under the same certificate. This way, a company that owns several websites can certify them with a single document.

Wrap Up

SSL encryption and its heir, the TSL protocol, have changed online data transfer forever. The strong encryption and demanding certification processes have made SSL an almost mandatory requirement in the modern interconnected world.


What is SSL?

SSL – Secure Sockets Layer is a protocol for establishing authenticated and encrypted links.

How Does SSL Work Between a Client and a Server?

The client and server begin communicating with what is called a “handshake”. During this procedure, the two sides authenticate each other, decide on encryption, and settle the communication rules.

The interaction between the client and server is based on a two-key system. The public key is freely shared and used to encrypt the data. The private key is kept secret and is used to decrypt it.

How does SSL work GCSE?

If you’re a secondary school teacher looking for educational materials on SSL and other technical topics, this site may be what you’re looking for.

How Does SSL Protect a Website?

SSL doesn’t protect the site as much as it offers value by protecting the user. So, how does SSL work? It secures sensitive data during transfer by encrypting it. The SSL certificate also verifies the site’s authenticity, thus protecting users from phishing attacks.


Deyan Georgiev

Deyan Georgiev

Deyan has been fascinated by technology his whole life. From the first Tetris game all the way to Falcon Heavy. Working for TechJury is like a dream come true, combining both his passions – writing and technology. In his free time (which is pretty scarce, thanks to his three kids), Deyan enjoys traveling and exploring new places. Always with a few chargers and a couple of gadgets in the backpack. He makes mean dizzying Island Paradise cocktails too.

Leave your comment

Your email address will not be published.