What is a SSL certificate
SSL (Secure Sockets Layer) is a cryptographic protocol
serving to encrypt the connection between the hosting server that stores
information and the web client (the browser of the visitor of the website).
This encrypted connection provides secure access to personal and business
information which should not be available to third parties. SSL is a technology
already used by millions of websites through which they provide protection for
online transactions with their customers.
How does SSL certificate work?
The SSL certificate
is installed on the hosting server of the website and the complex mechanism of the SSL protocol
remains in the background and is invisible to the client. The client and the server establish communication
with a procedure called Handshake. During this procedure the various means of
establishing secure connection are selected.
The handshake is done as soon as the client browser connects
with the server at which a SSL protocol is installed. Then the server provides several
mathematical functions for encryption. The highest function supported by the
client is chosen by the server and the client is informed about the function
chosen. The server then sends its information as digital certificate which
contains the details of the authority which has certified the server, the name of the server and the public key used
for the encryption. The user then gets to check the certificate‘s validation.
In order to generate session keys used for each connection the web client uses
the public key to encrypt a random number and sends the result back to the
server. The server than can decipher the number using its own private key. Now
both parties have created public and private keys used to secure the
information transmitted between the client and the server. This ends the
handshake and secures the connection from being exposed to other parties. If
any of the steps shown above breaks the handshake is over and the connection
will not be established.
This process is performed automatically by the browser and
the client and is virtually undetectable by the user.
The encryption which allows the for the connection to be
secured is a complicated mathematical process. Through this process all the
information is coded and then decoded by the client and the server. The level of SSL certificate encryption is characterized
by the length of the key used by the SSL certificate in bits. The most common
used SSL certificates are 40 bits, 56bits, 128 bits and 256 bits. The size of
the key defines and the level of security a SSL certificate has. A well secured
connection can be deciphered by a hacker equipped with the right tools for as
long as million years :)
Types of SSL certificates
The SSL certificates are usually divided in three groups RegularSSL Certificates, Wildcard SSL certificates and EV SSL certificates. The regular
certificates can be installed in one domain and secure the information received
or transmitted through this domain or subdomain only. If
you want to have encrypted secure connection over several subdomains you need
Wildcard SSL Certificate. It can be used to secure multiple (as much as you
have) subdomains on a single domain name.
The EV SSL certificate are issued to firms
and companies which are legally presented. These certificates are used to build
additional confidence in the company‘s customers.
Valid SSL Certificate
is a must if:
- Your site is an online store and accepts credit card payments or other orders
- Your site offers online services, subscribers has to go over signup process
- Your site supports login to user accounts, containing private or secure details
- Your site has any other type of transmitting client's data over the Internet
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