Why is SSL used?

Transport Layer Security (TLS), formerly known as Secure Sockets Layer (SSL), is a protocol used to establish encrypted links between a web server and a browser to enable secure transmission of data. SSL is used for several important reasons:

Why is SSL used?

Ensures Secure Data Transmission

SSL encryption protects data in transit between a browser and server. Information transmitted without SSL is visible to hackers using packet sniffers on public networks. SSL prevents data theft or modification by:

    Encrypting data using algorithms like AES, 3DES, RC4, etc. This renders data unreadable to hackers

    Using digital certificates to authenticate servers and establish identity

    Generating session keys unique to each connection for encrypted transmission

Table showing SSL protocol layers:

| Layer | Purpose |

|TLS/SSL Record Encrypt/Decrypt Data|

|TLS/SSL Handshake Authenticate, Negotiate Encryption|

|TCP|Transport Encrypted Segments|

|IP|Route Segments|

Validates Server Identity

    SSL certification issued by trusted Certificate Authorities validate server identity

    Browsers check server certificate ownership and domain name match before establishing connections

    Eliminates risks from fraudulent websites impersonating legitimate ones

    Provides trust to users that they are interfacing with authentic website

Protects Integrity of Data

    Hash functions in SSL detect changes or tampering of data during transmission

    Any manipulation identified ensures connection terminated immediately

    Guarantees end users receive data completely intact as sent initially

Privacy from Surveillance

    SSL hides browsing activities, data downloads, transactions from network surveillance

    Makes tracing activities back to specific users and devices difficult

    Provides confidentiality for sensitive personal or financial transactions

Compliance with Regulations

   SSL helps websites comply with various data security regulations including:

        Payment Card Industry Data Security Standard (PCI DSS) for card transactions

        Health Insurance Portability and Accountability Act (HIPAA) for health data

        Sarbanes Oxley Act (SOX) for public companies

        EU General Data Protection Regulation (GDPR)

Search Engine Ranking Signals

    Websites utilizing SSL encryption recognized as more legitimate, trustworthy by Google algorithms

    Positive influence on search engine optimization efforts and search rankings

Key Takeaways

    SSL encryption secures online data transmission through authentication, encryption, integrity checks

    Valid certificates establish trust in website identity and security for users

    Compliance with regulatory requirements for sensitive data achieved

    Increased search visibility due to perceived legitimacy and trust


In summary, SSL certificates enable essential security capabilities to websites via strong encryption protocols. Companies and users require assurance of data confidentiality and website authenticity provided by SSL when conducting online transactions. As cyberattacks and data breaches threaten online activities, SSL usage emerges as an imperative for security, privacy and trust.

Frequently Asked Questions

  1. What is an SSL certificate?
    An SSL certificate is a digital certificate issued by a Certificate Authority that verifies a website’s identity and enables encryption for secure data transmission.
  2. How does SSL work?
    SSL works through an encrypted link established using an SSL handshake between the browser and server to authenticate and securely transmit information.
  3. Is HTTP secure?
    No, HTTP has no encryption and does not secure data transmission between browsers and servers.
  4. What’s the difference between SSL and TLS?
    SSL refers to Secure Sockets Layer while TLS means Transport Layer Security. TLS is the newer version that replaced SSL. The terms are often still used interchangeably.
  5. Why is SSL important for websites?
    Websites use SSL for security, privacy, compliance with regulatory requirements and to build user trust through identity validation and encryption of sensitive data.
  6. Does SSL fully secure a website?
    While SSL heavily protects online data transmission, additional website security measures like firewalls, access controls and testing are required for comprehensive security.
  7. What are the Different Types of SSL?
    Common SSL types are Domain Validation (DV) which confirms domain ownership, Organization Validation (OV) verifying organization identity, and Extended Validation (EV) establishing legal entity identity.
  8. What SSL certificate does my site need?
    Public sites with user logins only require basic Domain Validation. Business websites handling payments or sensitive data may require Organization or Extended Validation certificates.
  9. What is 256 bit SSL encryption?
    256 bit encryption is a high level of SSL encryption using a 256 bit secure session key. It has over three trillion possible key combinations to prevent hackers from accessing data.
  10. How do I add SSL to my website?
    First purchase an SSL certificate, install certificate keys on your server, activate SSL on sites through server settings like the .htaccess file, redirect site URLs to HTTPS and update links.
  11. Can visitors still access my site if SSL expires?
    If your certificate expires, users may not be able access your website and will see expiration warnings. Renew promptly to maintain availability.
  12. Does SSL affect website performance?
    Negligible effect in most cases though initial handshakes can marginally increase page load times. Hardware acceleration and caching in modern browsers optimize SSL performance.
  13. What are self-signed certificates?
    Self-signed certificates are signed by their own creator, not a trusted certificate authority. They enable encryption but users cannot verify identity so are not advised for external-facing websites.
  14. How much do SSL certificates cost?
    Basic domain validation certificates range from $50 – $100 per year typically while extended validation certificates are over $150 annually for a single site depending on the issuing Certificate Authority.
  15. Can I use a free SSL certificate?
    Yes, some certificate authorities like Let’s Encrypt offer free basic domain validation certificates valid for 3 months suitable for personal websites and testing purposes.
  16. How long does an SSL certificate last?
    Standard validity ranges from one to three years after which renewal is required. Thirty day renewal grace periods enable continuation beyond expiry. Lifetime certificates are also available.
  17. How do I revoke an SSL certificate?
    You can revoke a certificate by requesting the issuing Certificate Authority to terminate it early before expiry through their revocation procedures. Distribution of a Certificate Revocation List invalidates it.
  18. Are SSL certificates universal?
    SSL certificates can only be installed on one site with designated server names. Unique certificates are required for each separate domain and subdomain. Wildcard certificates allow unlimited first-level subdomains.
  19. Can SSL connections experience errors?
    SSL errors like certificate warnings, revocation or expiration issues can fail secure connections resulting in mixed content or insecure website blocks needing immediate troubleshooting.
  20. How is an SSL connection terminated?
    To gracefully terminate a TLS connection, the client or server initiates a TLS closure alert to notify readiness to shutdown. The transport connection gets closed only after receiving the peer’s closure alert acknowledgement.


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