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SSL vs TLS - What's the Difference?

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols which were designed to provide secure communication over a computer network. SSL, developed in the mid-1990s, was the first widely adopted protocol for securing internet communications. TLS, introduced in 1999 as an upgrade to SSL, offers enhanced security features and improved performance. SSL has since been deprecated and TLS is the modern standard, providing stronger encryption and better protection for data integrity and privacy.

In this blog we explore:

What is a Secure Sockets Layer (SSL)?

A Secure Sockets Layer (SSL) is a cryptographic protocol developed by Netscape in the mid-1990s to secure internet communications. It was designed to provide privacy, authentication, and data integrity between web browsers and servers. SSL quickly became the standard for securing online transactions, such as e-commerce and online banking, due to its ability to encrypt data and ensure secure connections.

Despite its initial success, SSL had inherent weaknesses that made it susceptible to various attacks. In September 2014, Google discovered a serious SSL 3.0 vulnerability called Padding Oracle on Downgraded Legacy Encryption (POODLE), which hackers exploited to decrypt and steal confidential information. These vulnerabilities led to the development of TLS as a more secure successor to SSL.

What is Transport Layer Security (TLS)?

Transport Layer Security (TLS) is the successor to SSL, developed primarily to address the security vulnerabilities found. Originally introduced in 1999, and now on version 1.3, TLS provides enhanced security features and improved performance, making it the modern standard for secure internet communications. At its core TLS serves the same purpose as SSL - ensuring the privacy, integrity, and authenticity of data exchanged between web browsers and servers.

Key Differences Between SSL and TLS

The key difference between SSL and TLS is the introduction of several key improvements, including stronger encryption algorithms, better authentication mechanisms, and more robust key exchange methods. These enhancements significantly reduce the risk of attacks and ensure a higher level of security for data transmission. Some of the notable features and differences of TLS include:

  • Stronger Encryption: TLS supports advanced encryption algorithms, such as AES (Advanced Encryption Standard), which provides better protection against brute-force attacks.
  • Cryptographic Differences: While both protocols use similar concepts, TLS incorporates more robust cryptographic techniques. For example, TLS uses HMAC (Hash-based Message Authentication Code) for message integrity, which is more secure than the MAC (Message Authentication Code) used in SSL. Additionally, TLS supports more secure cipher suites and provides better protection against cryptographic attacks. Learn more about Hash-based cryptography with our support article.
  • Improved Authentication: TLS uses more secure methods for verifying the identity of communicating parties, reducing the risk of man-in-the-middle attacks. The TLS handshake process is more secure and allows for robust authentication mechanisms.
  • Performance Improvements: TLS also brings performance improvements over SSL. The protocol is designed to be more efficient, reducing the overhead associated with establishing secure connections. This results in faster handshake processes and lower latency, making TLS more suitable for modern web applications that require high performance and low response times.
  • Enhanced Key Exchange: TLS employs more secure key exchange protocols, such as Diffie-Hellman and Elliptic Curve Diffie-Hellman, to establish secure connections.  

Check what compatibility your software, platform or operating system has  

Why is the Term SSL Still Used?

The deprecation of SSL gave way to the TLS protocol as the sole alternative, which had addressed critical vulnerabilities and blazed the trail for future improvement as we head into the quantum computing era.  Obtaining TLS certificates from a reputable Certificate Authority (CA), along with incorporating effective certificate management into your business operations, are critical to ensuring compliance, security, and business continuity. The question is: why is the term SSL still used?

Despite the widespread adoption of TLS, the term SSL is still commonly used, leading to confusion in the market. This is largely due to the legacy naming convention, brand recognition, and search practices. SSL was very popular in the early days of the internet and is still a term associated with secure communication. But what not many people are aware of is that all versions of SSL are now deprecated. Even if you use a certificate that brands itself as SSL, it will actually support the latest TLS protocols. (In fact, even fewer would know that TLS 1.0 and TLS 1.1 were also formally deprecated in 2021.)

Common Use Cases for SSL / TLS

SSL / TLS is so widely used across the world that even if you haven’t heard of it, you’ve certainly been using it. Various applications and services use SSL / TLS encryption to ensure secure communications and transactions online. Some of the most common ones people use day-to-day include:

  • Web Browsing: TLS is used to secure HTTPS connections, protecting data exchanged between web browsers and websites.
  • Email Communication: TLS secures email communications by encrypting the connection between email clients and servers, as well as between email servers.
  • VPNs: TLS is used in Virtual Private Networks to secure data transmitted over public networks.
  • VoIP: TLS is utilized in Voice over IP services to encrypt voice communications and protect against eavesdropping.   
  • DevOps: In DevOps pipelines, TLS secures communication between different services and components, ensuring that data remains confidential, and integrity is maintained throughout the deployment process. 
  • IoT Devices: TLS secures communication between Internet of Things (IoT) devices and cloud servers, ensuring data integrity and privacy.
  • Internal Networks: TLS can be used within internal networks to secure communications between servers, devices, and applications, protecting against internal threats and unauthorized access.
  • Database Connections: TLS encrypts connections between applications and databases, safeguarding sensitive data during transmission.
  • Payment Gateways: TLS is crucial for securing transactions between e-commerce websites and payment processors, protecting financial information from interception.
  • Remote Desktop Protocol (RDP): TLS secures remote desktop connections, ensuring that data transmitted between the remote desktop client and server is encrypted.

How SSL / TLS Works

SSL / TLS uses a handshake process to establish a secure connection between a client and a server, with the aid of Public Key Infrastructure (PKI) to ensure confidentiality in exchanged data.

This process involves several steps:

Learn more about the TLS Handshake process 

Encryption and Decryption Mechanisms

Once the handshake process is complete, SSL / TLS uses PKI to protect data transmitted between the client and server. PKI encrypts the data, so it appears as ‘gibberish’ to anyone without access to the private decryption key. These mechanisms ensure that data remains confidential and cannot be intercepted or tampered with by unauthorized parties. 

Role of Certificates

Digital certificates play a crucial role in the SSL / TLS protocol. Certificates are issued by Certificate Authorities and contain the public key of the server. During the handshake process, the client verifies the authenticity of the server's certificate to ensure that it is communicating with a legitimate entity. This verification process helps prevent man-in-the-middle attacks and ensures the integrity of the secure connection.

Best Practices for Maintaining Secure Website Connections with SSL / TLS

Maintaining secure connections with SSL / TLS is crucial for protecting your website and its users. Here are some best practices to ensure robust security:

  1. Regularly Update Your Certificates: Ensure that your TLS certificates are always up to date. Renew them before they expire to avoid any disruptions in secure communication. Learn how to renew GlobalSign Certificates.
  2.  Automate Your Certificates: Implement an automation solution to manage your TLS certificates. Automation helps ensure timely renewals, reduces the risk of human error, and maintains continuous secure connections without manual intervention. This approach streamlines certificate management and enhances overall security.
  3. Monitor and Audit: Regularly monitor and audit your TLS configuration to identify and address any potential security issues. Use tools, such as automation solutions, to scan for vulnerabilities and ensure compliance with industry standards.
  4. Educate Your Team: Make sure your development and IT teams are well-versed in TLS best practices. Regular training and updates on the latest security trends can help maintain a secure environment.

By following these best practices, you can ensure that your website remains secure and provides a safe experience for your users.

What Lies Ahead for TLS Certificates? 

TLS will continuously evolve to address any newly discovered vulnerabilities. It will optimize handshakes for better connections and fortify encryption algorithms. It is predicted the TLS protocol will include patches and updates on post-quantum cryptography, as well as quantum-resistant algorithms to future-proof digital trust with safe certificates.

Meanwhile, the decreasing of certificate lifespans to 47 days will improve the security of online communications. This development, though, comes with a caveat: it will also make it more of a challenge for organizations with a larger volume of certificates, especially to effectively avoid unmonitored expirations, outages, and disruptions. When these issues arise, you need to be crypto-agile — to securely and rapidly manage digital certificates — and respond to cybersecurity threats within the soonest possible time.

It’s best to prioritize the continuous enhancement of internet security protocols so that the entire internet ecosystem may successfully adapt to emerging threats. In the wake of disruptions like the potential decrease to certificate lifespans, organization’s will need to shift to automated management, like those offered by the Automatic Certificate Management Environment (ACME) protocol to be able to maintain their TLS infrastructure.

Why You Need to Stay Updated

Staying updated with the latest security protocols is essential for protecting sensitive data and maintaining trust with your users. By adopting TLS and following best practices for secure connections, you can ensure compliance, security, and business continuity.

As we move towards an era of quantum computing, the importance of robust security measures will only increase. Obtaining TLS certificates from reputable Certificate Authorities, such as GlobalSign, and incorporating effective certificate management into your business operations are critical steps in safeguarding your digital identity.

Talk to us today to see how TLS certificate management can help your organization

Other SSL / TLS Frequently Asked Questions (FAQs)

What is the Validity Period of an SSL / TLS Certificate?

The validity period of an SSL/TLS certificate refers to the length of time the certificate is considered valid and can be used to secure communications. As of now, SSL/TLS certificates have a maximum validity period of 398 days, or about 13 months. This change was implemented in response to industry efforts to enhance security by reducing the lifespan of certificates, thereby minimizing the risk of compromised keys.

However, starting in March 2026, the validity period for SSL/TLS certificates will be further reduced in phases. By March 2029, the maximum validity period will be just 47 days. This shift aims to improve security by ensuring that certificates are renewed more frequently, reducing the window of opportunity for potential attacks. Learn More About Certificate Validity Changes.

How do I troubleshoot SSL / TLS connection issues?

To troubleshoot SSL/TLS connection issues, start by verifying that your TLS certificate is correctly installed and not expired. Check your server's configuration to ensure it uses the latest TLS version and supports strong cipher suites. Review your server logs for any error messages related to SSL/TLS connections. Use online tools to test your server's configuration and identify potential vulnerabilities. If issues persist, consult your Certificate Authority's support resources or seek assistance from a technical expert. Follow our guide to test your TLS certificate is properly installed.

How Can I Get TLS on my Website?

To implement SSL/TLS on your website, start by obtaining a TLS certificate from a reputable Certificate Authority. Install the certificate on your web server following the CA's instructions, which may vary based on your server software. Next, configure your server to use the latest TLS version and disable outdated protocols like SSL, ensuring strong cipher suites for enhanced security. Finally, test your server's TLS configuration using online tools to identify and address any vulnerabilities. For a more detailed guide on implementing TLS, please refer to our technical support articles.

Editor’s Note: This blog was originally published on February 13th, 2020 but has since been updated to reflect industry changes and new insights. 

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