SSL FAQ: What is SSL and how does it work?

New to SSL? Here's what you need to know to get started.

Q: What is SSL?

A: Secure Sockets Layer (SSL) is a protocol for enabling data encryption and site authentication on the Internet. Credit card numbers, health details and other sensitive information are transmitted only after being converted into a secure code. Domain authentication reassures site users that they're interacting with the site identified in the URL bar. Without SSL, online transactions would be vulnerable to interception by unauthorized parties. SSL is commonly used to protect communications between web browsers and servers. However, it is also used for server-to-server communications and for web-based applications.

Q: How do visitors know if a website is using SSL?

A: When a browser connects to a secure site, it retrieves the SSL certificate and checks to ensure the certificate has not expired, that it was issued by a certificate authority the browser trusts, and that it is being used by the website for which it was issued. If it fails on any of these checks, the browser will display a warning to the end user. If it succeeds on all checks, the user will see indicators of a secure connection:

  • The beginning of the URL or web address changes from http:// to https://
  • In the web address bar, a padlock or other security icon will indicate a current SSL certificate is encrypting the site

Q: What is a Certificate Authority?

A: An organization that issues SSL certificates is known as Certificate Authority (CA). The protection provided by an SSL certificate is only as good as the company that stands behind it. Web browsers like Firefox and Chrome maintain a list of trusted Certificate Authorities. If your site serves up one of these trusted certificates, the browser will recognize the site as secure.

Q: Why should I upgrade to GeoTrust?

A: An SSL certificate tells your visitors and customers they can trust your site. GeoTrust SSL certificates can be issued quickly—often within minutes, and they’re backed by the globally trusted Certificate Authority (CA), DigiCert. When you buy a GeoTrust SSL certificate, you get easy but powerful management tools, trusted website security and award-winning 24/7 support.

Q: How long does enrollment take and how soon will I be able to secure my site?

A: An SSL certificate may be issued within minutes of submitting your enrollment information, as long as the information is correct and the authorized administrator responds promptly to the confirmation email.

Q: What is a certificate signing request or CSR?

A: A CSR is a public key that you generate on your server according to your server software instructions. If you do not have access to your server, your web host or internet service provider will generate it for you. The CSR is required during the SSL certificate enrollment process, because it validates the specific information about your web server and your domain.

Q: What is domain control validation?

A: GeoTrust will confirm domain control by sending an email to the administrator listed with the registrar for the domain. If the authorized administrator does not reply, a second email will be sent to an email address at the domain, such as info@ or support@. (You may select a secondary email address during the enrollment process.) In addition to validation by email, you will be asked to provide a telephone number where you can be reached immediately after submitting your enrollment. If everything checks out, the SSL certificate is issued.

Q: What is a public/private key pair?

A: SSL uses unique cryptographic key pairs: each key pair consists of a secret private key and a related public key. Information encrypted with a public key can only be decrypted with the corresponding private key, and vice-versa.

Q: What is data encryption and why are there different levels?

A: Encryption is a mathematical process of coding and decoding information in order to keep data secure while traveling between computers. If raw, unencrypted data is sent, anyone who intercepts the information can easily understand it. The number of bits (40-bit, 56-bit, 128-bit, 256-bit) tells you the size of the key. Like a longer password, a larger key has more possible combinations. When an encrypted session is established, the encryption level is determined by the capability of the web browser, SSL certificate, web server, and client computer operating system.