PCI (Peripheral Component Interconnect) is a computer bus for attaching hardware devices in a computer. These devices can take either the form of an integrated circuit fitted onto the motherboard itself, called a planer device in the PCI specification or an expansion card that fits into a slot.SET (Secure Electronic Transaction) protocol, which is developed by Visa and Mastercard uses encryption for privacy and digital certificates to verify the three parties -the bank, the customer and the merchant. It ensures secure transactions online.Kerberos is a third-party authentication that validates the clients over the network and provides secure communication or access to network resources.