SSL vs TLS: Key Differences: A Simple Explainer

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Understanding the difference between SSL and TLS is essential for anyone concerned about online security. Both protocols are designed to protect online communications, but TLS has become a more secure and modern alternative to SSL . SSL once protected data exchanges, but its vulnerabilities led to the development of TLS, which now powers most HTTPS connections .

In this article, we'll look at how these protocols work, their key differences, and why switching from SSL to TLS is necessary to maintain secure online communications.

Table of contents

What is SSL and TLS?
What is SSL?
What is TLS?
Key Differences Between SSL and TLS
SSL vs TLS Certificates
What is SSL and TLS?
SSL (Secure Socket Layer) and TLS (Transport Layer Security) are cryptographic protocols designed to establish a secure connection between a client (such as a web browser) and a server. These protocols are necessary to protect data, especially sensitive information such as passwords and credit card numbers, from possible interception by intruders.

SSL was originally developed by Netscape in the 1990s to encrypt mobile app development service and authenticate communications on the Internet. However, due to various security vulnerabilities discovered over time, TLS was introduced as a more reliable and secure successor to SSL. Although SSL is no longer in use today, many people still refer to TLS connections as “SSL,” which can lead to confusion.

Why should you care? Understanding the difference between SSL and TLS is important to ensure that your website or application is using the most secure communication protocol.

What is SSL?
SSL , short for Secure Socket Layer , was the original protocol created to secure internet communications. It uses cryptographic algorithms to encrypt data , ensuring that any information exchanged between a web server and a browser remains private and cannot be intercepted by unauthorized parties.




SSL works by performing a handshake process between the client and server. During this process, both parties exchange cryptographic keys and verify the server's identity using a digital certificate . Once this handshake is complete, an encrypted connection is established, ensuring secure data transfer.

However, SSL has several vulnerabilities . It uses older encryption algorithms such as MD5 , which are susceptible to cryptographic attacks. This led to SSL eventually being discontinued. By the time SSL 3.0 was released in 1996, it had already been replaced by TLS due to serious security flaws.

SSL may no longer be in use, but its legacy is important to understanding modern web security.

What is TLS?
TLS , or Transport Layer Security , is the successor protocol to SSL. It was first introduced in 1999 as an update to SSL 3.0, which addressed security vulnerabilities present in the older protocol. TLS provides the same core security features—encryption, authentication, and data integrity—but with significant improvements.

One of the main advantages of TLS is its support for stronger encryption algorithms such as AES (Advanced Encryption Standard) and ChaCha20 , making it much more secure than SSL. Additionally, TLS supports forward secrecy , which means that even if the server’s private key is compromised, past sessions will remain secure.