SSL/TLS Basics

Introduction

Secure Sockets Layer (SSL) and Transport Layer Security (TLS) are cryptographic protocols designed to provide secure communication over a computer network. SSL has been deprecated and replaced by TLS, which is more secure and efficient.

What are SSL and TLS?

SSL and TLS are protocols that encrypt the connection between a client (like a web browser) and a server (like a website). They ensure that data transmitted remains private and integral.

How SSL/TLS Works

The SSL/TLS handshake process involves several steps:

            1. Client Hello: The client sends a message to the server indicating that it wishes to establish a secure session.
            2. Server Hello: The server responds with its SSL/TLS version, cipher settings, and its digital certificate.
            3. Authentication: The client verifies the server's certificate against a trusted Certificate Authority (CA).
            4. Session Keys: Both parties generate session keys for encryption.
            5. Secure Connection: The client and server exchange messages encrypted with the session keys.
        

        graph TD;
            A[Client Hello] --> B[Server Hello];
            B --> C{Verify Certificate?};
            C -->|Yes| D[Generate Session Keys];
            C -->|No| E[Connection Failed];
            D --> F[Secure Connection Established];
        

Best Practices

• Always use the latest version of TLS (currently TLS 1.3).
• Regularly update and manage your certificates.
• Use strong encryption algorithms and key lengths.
• Implement HSTS (HTTP Strict Transport Security) to force secure connections.
• Regularly audit your SSL/TLS configurations.

FAQ