Abbreviated as SSL, Secure Socket Layer is an encryption technology to secure the data exchange between a website and its visitor's web browser. Normally, when a user communicates with a website, say submits his credit card information, the data travels to the server in plain text, which is susceptible to data theft. Whereas if this data is encrypted, then no eavesdropper can read it. Thus, it's essential to secure a website with SSL.<.p>
This is a digital identity of a company, which ensures that a visitor is talking only to its intended website and whatever data he submits to the site is encoded and reaches only the intended site. This system is analogous to banks recognizing their customers by their signatures. In this case, the browsers (thereby the end-users) are programmed to trust these Certifying Authority (CA) presented certificates.
Regulatory organizations, with the help of standard policies, issue certificates to a domain declaring it trustworthy. Every certificate they generate is unique to the company they are certifying, which makes identification easy.
CAs secure all necessary information about a company before issuing a certificate and also keep their records updated, which adds to the trustworthiness. Some of the popular CAs include Verisign, Comodo & GoDaddy etc.
In order for a CA to generate an SSL certificate for a company, it first collects information about that company and other identifiers such as public key (digital signature), and then binds them all with its certificate. In doing so, it generates a unique identifier for the company.
Thus every certificate issuance process begins with a "certificate request" from the company. Certifying Authorities refer to this process as Certificate Signing Request (CSR). The Certifying Authorities accept the company information and digital signatures in a special file format, namely .csr format.
