A TLS/SSL is used to encrypt data and communications between web servers and browsers. But I am sure you already know what an SSL Certificate is.
When people talk of TLS certificates, they often refer to server certificates. As the name implies, server certificates are essential in authenticating servers to clients. Typically, this is the standard way of authentication. But have you ever wondered how it would be when you wanted to authenticate the client to the browser? This is where 2 Way SSL (or two-way SSL if you like) comes into sight. Wondering what that is and how it works?
Want to know what that is and how it functions? No more enigmas! We will explain what a two-way SSL certificate is and how it works in this article.
How do TLS certificates provide authentication?
- First, the owner of a website purchases an SSL certificate for their website domain/s. The website owner then sends an unsigned certificate together with the associated public keys to the certificate authority.
- The certificate authority is mandated to ascertain the validity of the person requesting the certificate and confirm domain ownership. The technical process for this is the Validation process. Suppose the certificate authority validates domain ownership and the requestor’s authenticity successfully. In that case, it will issue the certificate, and attach the public key of the servers to the SSL certificate. Also, sign it with its intermediate root certificate.
SSL handshake – An overview
The SSL handshake process happens when a web visitor connects to a website via a web browser. Once the SSL handshake is complete, the browser generates a session key and uses the SSL certificate’s public key to encrypt sessions. When decrypting encrypted sessions, the server applies the private keys.
The primary goal of an SSL handshake is to ensure data integrity and privacy for communication between a server and a client. During the handshake, the server and client exchange vital data to establish a secure connection.
Understanding how SSL authentication works helps clarify the concept of the SSL handshake. Do you know what makes one-way and two-way SSL different? It’s the SSL handshake process and the type of SSL certificate.
Now that you have a clear understanding of the process, let us now proceed to look at what a two-way SSL certificate is and its significance.
What is Two Way SSL Authentication?
The 2-way or Two-way is also known as mutual authentication. It is used where the server and the client need to authenticate one another for strong security.
The two-way SSL certificate not only validates the web server (as is the case for one-way SSL certificates) but also web browsers. Both of these identities would be verified during the SSL handshake process.
The following are the steps involved in the two-way SSL handshake process.
- For a web visitor using a browser to access a website, the web browser will try to establish a secure HTTPS connection with the website servers. The browser will send the supported cipher suites to the website servers.
- The server will respond to its request by sending its SSL/TLS certificate to the web browser (client’s end).
- The browser will then need to establish the authenticity and legitimacy of the SSL certificate to confirm that it is genuine. For instance, the browser must confirm that the SSL certificate is up to date, not revoked, configured appropriately, and supports the latest algorithms. The validation process continues by the browser checking the pre-installed root store of the certificate authority to ascertain that the attached signature is genuine.
- Upon successful verification of the website servers, the client (users’ browser) will send its public certificate to the server. It is now the turn of the server to validate the validity of the certificate authority’s signature and the SSL certificate presented by the web browser.
- If all these requirements are met, the SSL handshake process is completed, and the browser generates the session keys.
As you would notice, there are additional steps in the two-way SSL handshake process. Unlike the one-way SSL process, the two-way SSL handshake process entails the browser sending its public key to the server. The server will then need to verify the validity of the signature of the certificate authority. These steps are not covered in the one-way SSL authentication.
Here are some of the most crucial elements of the two-way SSL authentication process;
- A private key
- Root certificate
- An intermediate certificate of the certificate authority
- A personal authentication certificate
The Significance of the Two-Way Certificate
You now understand what a two-way SSL certificate is, how it works and how different it is from a one-way SSL certificate. The next issue to address will be the significance of the two-way SSL certificate. You are probably wondering, “is a two-way SSL certificate really necessary?”
You should understand that a website uses two-way authentications to choose the clients it wants to interact with without putting its security at stake. Take the instance of an entity’s intranet website that typically exists to aid employees within the organization in communicating with other organizational stakeholders.
The organization does not want outside parties to access its intranet network and would love to keep it as restricted as possible.
To further address the risk of unsolicited threats, stakeholders should be required to only access the network from work devices and not their gadgets. This is where an application called a two-way SSL certificate comes in – it helps make sure the right folks get into the network after proving who they are.
Organizations can leverage two-way SSL certificates to protect their websites against unauthorized access.
Where is the Two-way Certificate Authentication Most Suited?
- Two-way SSL certificates work best when a website owner wants to limit access to certain users.
- Organizations wishing to prevent financial fraud and other cybersecurity threats.
- Two-way SSL can help organizations to restrict access to their platform to only their employees and/or customers.
To Sum It Up
The whole aspect of an SSL certificate is fully jargonized, which a regular internet user might find difficult to understand.
For instance, the aspect of a 2-way SSL certificate can be new to most people. But it is important for you to understand such concepts, especially if you are in the cybersecurity industry.
This article has given you a headstart by explaining what a two-way SSL certificate is and how it works.
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