What is SSL (Secure Sockets Layer)?

What is SSL?

SSL (Secure Sockets Layer) is a cryptographic protocol designed to provide secure communication over the internet. It establishes an encrypted connection between a web server and a client, typically a browser or application, ensuring that all data transmitted remains private and integral.

Although SSL has largely been replaced by its more secure successor, TLS (Transport Layer Security), the term SSL is still commonly used in reference to website security and digital certificates (e.g., SSL certificate), even when TLS is technically in use.

SSL plays a foundational role in securing online activities such as online banking, e-commerce transactions, and sensitive data transfers. When SSL is active, users see “https://” in the browser address bar, often accompanied by a padlock icon, both indicators that the connection is encrypted.

How SSL Works

1. Handshake: When a browser connects to a secure site, it initiates an SSL handshake where the server provides its SSL certificate.
2. Authentication: The browser verifies the certificate's authenticity via a trusted Certificate Authority (CA).
3. Encryption: Once verified, a symmetric encryption key is generated and exchanged securely.
4. Secure Session: All data transmitted between the browser and the server is encrypted using this key, protecting it from interception or tampering.
   

Key Benefits of SSL

• Data Encryption: SSL encrypts data in transit to prevent eavesdropping and data breaches.
• Authentication: Ensures users are communicating with the intended and trusted website.
• Data Integrity: Detects any tampering or corruption of data during transmission.
• User Trust: SSL-enabled sites gain user trust, as indicated by HTTPS and padlock symbols.
• Regulatory Compliance: Helps meet standards such as GDPR, HIPAA, and PCI DSS for protecting sensitive information.
  

Common Use Cases

• Securing websites and web applications
• Protecting user login credentials
• Encrypting financial transactions
• Safeguarding api communications
• Supporting compliance in regulated industries
  
  

SSL vs TLS

While SSL laid the groundwork for secure communications, it is now considered obsolete due to known vulnerabilities. TLS is the modern standard, offering stronger encryption, faster performance, and better security mechanisms. However, the term SSL is still often used colloquially and in certificate naming.

How Illumio Supports Encrypted Communications

While Illumio focuses on segmentation and its solutions operate seamlessly in environments where SSL/TLS encryption is in place. By visualizing encrypted traffic flows and enforcing segmentation based on application context — not just port or IP — Illumio enhances security without disrupting encrypted communications.