Enhancement of data transfer safety level and the growth of the SSL technology is due to the increasing number of online transactions.

Daily used, the SSL protocole is totally transparent and works without any manipulation from the webuser.

What is it ? How does it work ?

• What's SSL ?
• What's a digital certificate ?
  
  

• The server certificate
  
• The developer certificate
  
• The Wildcard certificate
• The multiple sites certificate

What's SSL ?

Developed by Netscape, the SSL (Secure Socket Layer) or TLS (Transport Layer Security), is a protocole used to secure online transactions.

It has several missions:

• Authentify the server
  
• Guarantee the confidentiality of exchanged datas
• Assure those datas integrity
• Optionaly identify a client through its digital certificate
  

HOW DOES IT WORK ?

The SSL protocole creates a communication channel between a client and a server independently from the protocole, it secures online transactions (HTTP protocole) as well as FTP, IMAP or POP protocoles connexions.

That communication channel is an opaque tunnel that prevents anybody to see the content of the transaction.

In a schematic way:


It can be compared to the mechanism of a lock (public key) and its key (private key):

The privet key is saved on the server.
The public key, known by anybody encrypts sending datas, that are decoded on the server by the privet key.



What's a digital certificate ?

A SSL certificate is a digital ID whose goal is to identify the owner of a server, a website or an Email address.

It is issued by a trusted third part called a certification authority,such as Thawte,that testifies the certificate's owner identity.



The server certificate

To make the SSL security work (for online transactions for example) a server certificate is required.

A server certificate carries:

• The name of the privet key owner
  
• The name of the certification authority that has issued the certificate
• The certificate validity period
  
• A serial number...

WHAT DOES THE WEBUSER SEE

When surfing, a webuser can see information about websites on the address bar.

On Firefox 3 :


Firefox 3 discerns 5 kinds of websites according to the information they deliver. Each kind owns its proper warning alert:

No information about the identity of the website's owner.The website does not carry any certificate.

Situated between non-secured websites and EV certificates. It gathers 1-factor certificates (aka domain-validated : low safety level, there's a cypherment but the website owner's not known), 2-factor (domain and organization validated) and 3-factor (domain, organization and physical existence validated).

High safety level provided by an EV certificate (extended validation). All the information about the website's owner are known. The connexion between the client and the server is entirely encrypted. The green bar is displayed.

The website's certificate is disabled or contains false information.

Appears on websites registered on your browser's known dangerous websites list.The access of the website is submited to your full acceptance.

ON OTHER BROWSERS :


SAFETY LOCK DISPLAY :




The wildcard certificate

A Wildcard certificate can secure several subdomain names (such as:*.domain.com). It works the same way than a classical server certificate and carries the same kind of information.

Instead of displaying a classical domain name,it contains a generic web address : *.domain.com.The star is instinctively replaced by the browser that searches if a certificate has been issued for the subdomain.


the multiple sites certificate

The multiple sites technology enables several websites,hosted on a same server, to be secured by one certificate. It prevents websites owners to purchasing a different certificate for each one of their sites.

That kind of certificate is issued by GlobalSign.You can secure 6 SANs (Subject Alternative Names) with the GlobalSign UCC.

Pros of the multiple sites certificate :

• One purchase for several domain
• One audit:time saving
• Money saving