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SSL vs TLS – What’s the Difference?

SSL & TLS are two critical cryptographic protocols that help encryption and authentication between web servers & clients. SSL means Secure Sockets Layer, while TLS is Transport Layer Security. Fundamentally, both of them serve the same purpose of securing data transmission. However, they are not entirely interchangeable. Let’s look at the differences between them in this SSL vs TLS guide.


1. SSL vs TLS – Origins & Development


SSL was developed by Netscape in the early 1990s to secure online transactions. It went through several iterations, with SSL 3.0 being the most widely adopted version.


TLS emerged as an upgraded version of SSL to address its vulnerabilities and shortcomings. It was introduced by the Internet Engineering Task Force (IETF) in 1999, with TLS 1.0 essentially being SSL 3.1.

2. SSL vs TLS – Security Enhancements


Despite its initial popularity, SSL had inherent security flaws, including vulnerabilities like POODLE and BEAST, which rendered it insecure for modern internet use.


TLS was designed with robust security features and improved cryptographic algorithms to mitigate the weaknesses of SSL. It introduced more robust cipher suites and protocols to ensure better protection against potential threats.

3. SSL vs TLS – Compatibility


Older versions of SSL are widely supported by web browsers & servers; however, their usage has significantly declined due to security concerns.


TLS has become the de facto standard for secure communication on the internet. Modern web browsers and servers predominantly support TLS, with many discontinuing support for older SSL versions.

4. SSL vs TLS – Protocol Versions


The SSL protocol encompasses SSL 1.0, SSL 2.0, SSL 3.0, and TLS 1.0 (often called SSL 3.1). However, SSL 2.0 & SSL 3.0 are considered obsolete & insecure.


TLS has seen multiple versions, including TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3, each introducing betterment in security & performance. TLS 1.3, the latest version, offers improved speed and encryption algorithms.

5. SSL vs TLS – Handshake Process


The SSL handshake process involves several steps, including cipher suite negotiation, key exchange, and authentication – to establish a secure connection between the client & the server.


TLS follows a similar handshake process, but it focuses on security & efficiency improvements. TLS 1.3, in particular, streamlines the handshake process to reduce latency and enhance overall performance.

6. SSL vs TLS – Performance Impact


Due to its older design & vulnerabilities, SSL implementations often incur higher computational overhead, leading to slower performance than TLS.


TLS implementations, especially newer versions like TLS 1.3, are optimized for improved performance and reduced latency. This optimization makes TLS more suitable for modern web applications & services.

7. SSL vs TLS – Forward Secrecy


SSL lacks perfect forward secrecy (PFS), which ensures session keys remain secure even if the private key is compromised in the future.


TLS, particularly versions 1.2 & 1.3, incorporates forward secrecy mechanisms, enhancing security by generating unique session keys for each session. This prevents the decryption of past communications even if the long-term private keys are compromised.

8. SSL vs TLS – Adoption & Industry Support


Despite its decline in usage, SSL is still present in legacy systems and applications, necessitating continued support for interoperability.


TLS has garnered widespread adoption and support across the internet ecosystem, with industry stakeholders actively promoting its use to ensure a safer online environment.


SSL supports the Fortezza algorithm.TLS does not support the Fortezza algorithm.
SSL is the 3.0 version.TLS is the 1.0 version.
In SSL, master secret is created with the Message digest.In TLS, a Pseudo-random function is used to create a master secret.
In SSL, the Message Authentication Code protocol is used.In TLS, Hashed Message Authentication Code protocol is used
SSL is more sophisticated than TLS.TLS  is simple.
SSL is less secure than TLS.TLS provides high security.
SSL is slower &  less reliable.TLS is highly reliable & upgraded with less latency.
SSL has been depreciated.TLS is still widely used.
SSL uses a port to set up explicit connections.TLS uses protocol to set up implicit connections.

How TLS & SSL Work at a Basic Level?

As you read earlier, TLS & SSL are cryptographic protocols to ensure secure communication over the web. Here are the basics consisting of how they function:

Handshake Initialization

  • When a client, like your web browser, wants to establish a secure connection with a server, it initiates a handshake by sending a “Hello” message to the server.
  • The server responds with its “Hello” message, including information like supported cryptographic algorithms and a digital certificate.

Certificate Verification

  • The client verifies the server’s virtual certificate for authenticity. This certificate has the server’s public key, issued by a trusted Certificate Authority (CA).
  • If the certificate is valid & trusted, the client proceeds with the handshake. Otherwise, it may terminate the connection to prevent potential security risks.

Key Exchange

  • During the handshake, the client and server agree on a shared secret key that will be used for encrypting & decrypting data during the session.
  • This key exchange process ensures that only the client & server can read the transmitted data, even if intercepted by a third party.

Encryption & Data Transmission

  • Data transmission starts once the handshake is complete and the shared secret key is established.
  • All data exchanged between the client & server is encrypted using symmetric encryption algorithms, ensuring confidentiality & integrity.

Session Management

  • TLS & SSL protocols support session resumption, allowing clients to reconnect to a server without repeating the entire handshake process.
  • Session tickets or session IDs are used to resume previous sessions quickly, reducing latency and server load.


Although TLS & SSL share a common goal of securing internet communication, their differences are significant – particularly in terms of security, performance, and protocol enhancements. With TLS being the successor designed to address the shortcomings of SSL, its widespread adoption and continued evolution signify its importance in safeguarding data privacy & integrity in today’s digital age. If you need help with SSL & TLS, connect with top server providers like Leasepacket.


Q.1 What’s the difference between SSL & TLS?

SSL & TLS are cryptographic protocols used to secure communication over the internet. TLS is the successor of SSL, offering enhanced security features and improvements.

Q.2 Are SSL & TLS the same thing?

No! SSL & TLS are not the same – although they serve similar purposes. TLS was developed as an improved version of SSL to address its vulnerabilities & weaknesses.

Q.3 Which one is more secure, SSL or TLS?

TLS is generally considered more secure than SSL. It incorporates robust cryptographic algorithms and security measures to protect data transmission against potential threats.

Q.4 Can SSL & TLS be used interchangeably?

While SSL & TLS serve the same fundamental purpose of securing data transmission, they are not entirely interchangeable. TLS is the recommended protocol due to its enhanced security features and broader industry adoption

Q.5 Do web browsers support both SSL & TLS?

Modern web browsers primarily support TLS, with many discontinuing support for older SSL versions due to security concerns. It’s crucial to ensure that websites use TLS for secure communication.

Q.6 Is it necessary to upgrade from SSL to TLS?

Yes! It’s highly recommended to upgrade from SSL to TLS for improved security. Using outdated SSL versions poses security risks, as they may be vulnerable to various attacks. Upgrading to TLS ensures better protection for data transmitted over the internet.