The handshake protocol in TLS/SSL is a crucial element in ensuring secure communication over the Internet. It establishes a protected connection between the client and the server, allowing the exchange of sensitive information without the risk of interception or tampering. This intricate protocol involves several steps, which can be broadly explained as follows:
what is Client Hello?
The client kicks off the handshake by sending a friendly “Client Hello” message to the server. This message contains details about the client’s supported protocols, cipher suites, and compression algorithms.
what is Server Hello?
The server replies with a cheerful “Server Hello” message, sharing its own supported protocols, cipher suites, and compression algorithms. It also presents its digital certificate, revealing information about the server’s identity and its public key.
Server key exchange
The server sends a “Server Key Exchange” message with its ephemeral public key, which encrypts the communication between the client and server.
Certificate verify
The client validates the server’s certificate by checking its signature and revocation status. If all checks pass, the client moves on to the next step.
Client key exchange
The client sends a “Client Key Exchange” message with its ephemeral public key, contributing to the encryption of communication.
Finished
Both the client and server send Finished messages containing a MAC (message authentication code) that is calculated using the negotiated cryptographic algorithms and the session keys. These messages ensure that the handshake has been completed successfully and that the data exchanged during the handshake has not been tampered with.
what is the usage of TLS/SSL?
TLS/SSL is vital for secure communication on the internet, utilized by websites, online banking services, and other applications requiring secure data transmission. The TLS/SSL handshake protocol offers several advantages, including:
Confidentiality
Encrypts communication, preventing eavesdropping.
Integrity
Ensures data exchanged remains untampered.
Authentication
Confirms the legitimacy of the communicating parties.
what is TLS Version?
Transport Layer Security (TLS) is integral for secure data transmission on the internet. Let’s explore the various TLS versions and their key differences that have shaped this fundamental security protocol’s evolution.
TLS1.0
- Introduction: Released in 1999, upgrading from SSL 3.0, TLS 1.0 improved security with stronger authentication and key exchange methods.
- Differences: Despite advancements, vulnerabilities like the BEAST attack prompted the development of more secure versions.
TLS1.1
- Introduction: Released in 2006, TLS 1.1 aimed to address vulnerabilities in TLS 1.0, enhancing protection against certain attacks.
- Differences: While strengthening security, it retained compatibility with TLS 1.0 but became susceptible to new threats as technology evolved.
TLS1.2
- Introduction: Released in 2008, TLS 1.2 brought substantial security enhancements, including stronger cipher suites and resistance against various attacks.
- Differences: Marked improvement with robust security features and better resistance against vulnerabilities.
TLS1.3
- Introduction: Released in 2018, TLS 1.3 overhauled the protocol, focusing on security, and performance, and eliminating obsolete cryptographic algorithms.
- Differences: Streamlined handshake, removal of outdated features, and mandatory forward secrecy for enhanced security.
Key Differences Across TLS Versions
- Cipher Suites:
- Evolution from weaker to stronger algorithms.
- Handshake Process:
- More efficient and secure in later versions.
- Key Exchange Mechanisms:
- Continuous refinement for stronger cryptography.
- Support for Forward Secrecy:
- Became mandatory in TLS 1.3.
- Removal of Vulnerable Protocols and Features:
- Phased out to enhance security.
As technology advances, TLS evolves, and upgrading to the latest version is crucial for a secure communication infrastructure in the face of changing cybersecurity challenges.
Related Read: what is SSH
