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  2. Introduction to SSL and How SSL Works

Introduction to SSL
Learn about Symantec SSL Certificates

Symantec SSL Certificates provide solutions that allow companies and consumers to engage in communications and commerce online with confidence.

Secure Sockets Layer (SSL): How It Works

What Happens When a Browser Encounters SSL

  1. A browser attempts to connect to a website secured with SSL.
  2. The browser requests that the web server identify itself.
  3. The server sends the browser a copy of its SSL Certificate.
  4. The browser checks whether it trusts the SSL Certificate. If so, it sends a message to the server.
  5. The server sends back a digitally signed acknowledgement to start an SSL encrypted session.
  6. Encrypted data is shared between the browser and the server.

Encryption Protects Data During Transmission

Web servers and web browsers rely on the Secure Sockets Layer (SSL) protocol to help users protect their data during transfer by create a uniquely encrypted channel for private communications over the public Internet. Each SSL Certificate consists of a key pair as well as verified identification information. When a web browser (or client) points to a secured website, the server shares the public key with the client to establish an encryption method and a unique session key. The client confirms that it recognizes and trusts the issuer of the SSL Certificate. This process is known as the "SSL handshake" and it begins a secure session that protects message privacy and message integrity.

Credentials Establish Identity Online

Credentials for establishing identity are common: a driver’s license, a passport, a company badge. SSL Certificates are credentials for the online world, uniquely issued to a specific domain and web server and authenticated by the SSL Certificate provider. When a browser connects to a server, the server sends the identification information to the browser.

To view a websites’ credentials:

  • Click the closed padlock in a browser window
  • Click the trust mark (such as a Norton Secured Seal)
  • Look in the green address bar triggered by an Extended Validation (EV) SSL

Authentication Generates Trust in Credentials

Trust of a credential depends on confidence in the credential issuer, because the issuer vouches for the credential’s authenticity. Certificate Authorities use a variety of authentication methods to verify information provided by organizations. Symantec, the leading Certificate Authority, is well known and trusted by browser vendors because of our rigorous authentication methods and highly reliable infrastructure. Browsers extend that trust to SSL Certificates issued by Symantec.

Extend Protection beyond HTTPS

Symantec SSL Certificates offer more services to protect your site and grow your online business. Our combination of SSL, vulnerability assessment and daily website malware scanning helps you provide site visitors with a safer online experience and extend security beyond https to your public-facing web pages. The Norton Secured Seal and Symantec Seal-in-Search technology help assure your customers that your site is safe from search to browse to buy.

To learn more about how SSL certificates work and the benefits of implementing SSL on your website, visit our "SSL Explained" interactive resource.

Extended Validation and SSL Security

For businesses with a high profile brand, using Extended Validation (EV) SSL Certificates has proven to be an effective defense against phishing scams. For any online business, using SSL with EV may have a big impact on the bottom line. Online shoppers are more likely to enter their credit card and/or other confidential financial information into a website with the SSL EV green bar.

Phishing and Online Fraud Undermine Customer Confidence

Concerns about identity theft and browser warnings erode consumer confidence, even on secured pages.

To regain their trust, site owners need an easy, reliable way to show customers that their transactions are secure and they are who they say they are. Certificate Authorities and Internet browser vendors have combined forces to establish the EV standard for SSL Certificates.

The Green Address Bar Restores Trust with Extended Validation

An EV SSL Certificate gives customers more confidence that they are interacting with a trusted website and that their information is secure. An EV SSL Certificate triggers high-security web browsers to display your organization’s name in a green address bar and show the name of the Certificate Authority that issued it. The Certificate Authority uses an audited, rigorous authentication method and browsers control the display, making it difficult for phishers and counterfeiters to hijack your brand and your customers.

Symantec Green Address Bar

Why Symantec EV SSL?

Symantec helped lead the development of Extended Validation and as of January 2012 has issued more EV SSL Certificates than any other Certificate Authority.* Our rigorous authentication practices set the standard for online identity assurance and are audited by KPMG. Continuous investment in research and infrastructure helps Symantec maintain the highest standard of practice in the industry and stay well ahead of evolving security risks.

* Includes Symantec subsidiaries, resellers, and affiliates.

Symantec SSL certificates now offer you the choice of three different encryption algorithms—RSA, DSA, and ECC—to help you create a more secure and scalable future for your business.

Elliptic Curve Cryptography (ECC) Algorithm

  • An ECC certificate is included at no additional cost with all Symantec Premium SSL certificates.
  • ECC provides stronger security and increased performance: it offers better protection than currently adopted encryption methods, but uses shorter key lengths (e.g. 256 bit ECC key provides the same level of security as 3,072 RSA key). The result? Stronger security that can handle the explosion in mobile device and tablet connections.
  • ECC key lengths increase at a slower rate than other encryption method keys as security levels increase, potentially extending the life of your existing hardware and giving you a greater return on your investment.
  • Symantec's ECC certificate roots have been in place for over five years: You can be confident that your ECC certificate will work throughout your ecosystem
  • US Government approved: ECC is FIPS-certified (US Federal Information Processing Standard) and endorsed by the US National Security Agency.

Digital Signature Algorithm (DSA)

  • A DSA certificate is included at no additional cost with all Symantec Standard and Premium SSL certificates.
  • Delivers the same level of security and performance as the RSA algorithm, but uses a different algorithm for signing and encryption.
  • Offers a broader array of encryption options: You can install just RSA, just DSA, or both to enhance website security. (Apache server can support both RSA and DSA certificates in tandem on a single web server.)
  • Gives you more choices and greater flexibility to help make it easier to keep up with evolving national government requirements.
  • Helps maximize your ecosystem reach to everyone with whom your company does business.
  • DSA is US Government approved: DSA was created by the NSA in 1991 and is US Defense Security Service and FIPS-certified.
* Encryption level depends on the web browser, operating system, and host server.
** Internet Explorer browser versions prior to 3.02 and Netscape browser versions prior to 4.02 are not capable of 128-bit encryption with any SSL Certificate.

Learn more

An experimental study of TLS Forward Secrecy deployment

Try a 30-Day Test Certificate

Symantec is the premier provider of SSL Certificates. Try a free, instantly-issued Symantec test certificate to evaluate SSL encryption before you deploy it in a production environment.

  Symantec SSL Test Certificate
How to try
What visitors see HTTPS in Browser Bar
If your website lies in a test environment to where visitors will not navigate
If you want to
  • secure data transfer with SSL encryption
  • test SSL encryption in a pre-production environment
What you get
  • Risk-free 30-day test certificate
  • Ability to test encryption within your test environment
  • Instant issuance
More information
  • Ability to test multiple times for the same domain
  • Limited to Secure Site SSL Certificates
  • Uses a non-production root
  • Not for use on publicly-facing websites

What would you like to do?

Buy a Symantec SSL Certificate

More value, no additional cost


Install Norton Secured Seal

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Try a Symantec SSL Certificate

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Beginner's Guide to SSL