Digital certificate-security of transaction

Digital certificates are set of data that will have the information required to ensure the identity of an individual or an organization. The digital certificate ensures that public key in the certificate is the same as that of the person to whom the certificate is being issued. Digital certificates are issued by certification authorities Thawte and VeriSign are well known examples of CA.
Digital certificates should have the following information
• serial number  for  digital certificate
• public key of the owner
• name of the owner of the service provider
• name of the certification authority that has issued that certificate
• digital certification authority
• date of expiry of digital certificate
Digital certificates will contain additional information includes
Registration information (County, age, sex, postal code)
Postal address/email address
If you are offering a payment transaction service and you want to get a digital certificate
you have to follow these procedures.
Sender has to send a request with details such as name, public key to the CA.
The CA creates a message using the details sent in the request. The CA signs the message with its private key and get a signature. The CA returns the message and signature to the  sender.
The sender sends the certificate to the receiver.
The recipient checks the validity of the signature using the CAs public key if signature is verified, recipient accepts sender’s public key.