TLS (Transport Layer Security) has gone through several versions, each introducing improvements in security, performance, and functionality. Here’s an overview of the different TLS versions:

1. TLS 1.0:
   • Published in January 1999, TLS 1.0 is based on SSL 3.0, with minor modifications.
   • Although an improvement over SSL 3.0, TLS 1.0 inherited some of its vulnerabilities.
   • Vulnerabilities such as BEAST (Browser Exploit Against SSL/TLS) and POODLE (Padding Oracle On Downgraded Legacy Encryption) were discovered in TLS 1.0.
   • Despite being deprecated due to security concerns, TLS 1.0 is still supported by many systems for backward compatibility reasons.
   • Notably, it lacks support for modern cryptographic algorithms and features found in later versions.
2. TLS 1.1:
   • Published in April 2006, TLS 1.1 addressed some of the vulnerabilities present in TLS 1.0.
   • Introduced support for new cipher suites and cryptographic algorithms, including AES encryption with HMAC-SHA1 authentication.
   • Provided protection against certain downgrade attacks by requiring explicit padding.
   • Despite its improvements, TLS 1.1 did not gain widespread adoption due to its limited security enhancements compared to later versions.
3. TLS 1.2:
   • Published in August 2008, TLS 1.2 brought significant security improvements over TLS 1.1.
   • Introduced support for authenticated encryption with Associated Data (AEAD) cipher suites, such as AES-GCM and ChaCha20-Poly1305, offering better protection against attacks like BEAST and Lucky Thirteen.
   • Supported Perfect Forward Secrecy (PFS) cipher suites, ensuring that session keys are ephemeral and not derived from long-term private keys.
   • Deprecated weak cryptographic algorithms and features present in TLS 1.0 and TLS 1.1, such as RC4 cipher suites and MD5/SHA-1 hash functions.
   • Widely adopted as the dominant TLS version for many years due to its robust security features and backward compatibility with older versions.
4. TLS 1.3:
   • Published in August 2018, TLS 1.3 represents a major overhaul of the TLS protocol, focusing on improving security, performance, and privacy.
   • Reduced handshake latency by minimizing the number of round trips required during the handshake process, resulting in faster connections.
   • Deprecated legacy cryptographic algorithms and features, including RSA key exchange and CBC mode cipher suites, in favor of modern, secure alternatives.
   • Mandatory support for Perfect Forward Secrecy (PFS) with ephemeral Diffie-Hellman key exchange or elliptic curve Diffie-Hellman (ECDHE) key exchange, ensuring forward secrecy for all connections.
   • Introduced 0-RTT (Zero Round Trip Time Resumption) mode, allowing clients to resume previous sessions without a full handshake, further improving connection speed.
   • TLS 1.3 is increasingly being adopted by web servers, browsers, and other TLS-enabled applications due to its enhanced security and performance benefits.

Overall, TLS has evolved over the years to address emerging security threats and vulnerabilities, with TLS 1.3 representing the latest and most secure version of the protocol. Organizations are encouraged to update their systems to support TLS 1.3 to ensure the highest level of security for their network communications.