What is a Certifying Authority (CA)?
A CA is a trusted third party willing to verify the ID of entities and their association with a given key, and later issue certificates attesting to that identity. In the passport analogy, the CA is similar to the Ministry of external affairs, which verifies your identification, creates a recognized and trusted document which certifies who you are, and issues the document to you. A CA can be within the organization itself or outside organization depending on the purpose of the certificates. A company may issue certificates to its employees for reason that only its employees can access to the company database but an internet user might request for a certificate from a well-known and trusted CA in order for him to do on-line transaction securely.
