Due to direct linkage of page to the payment gateway, transmission of non-encrypted packets, and without maintaining the database for the transactions a vulnerability is open for the attackers to intercept the packets and tamper with the package. The main aim is to prevent these packages to be read and tampered with for the pages that are directly linked to the payment gateways.
Sending Encrypted Package (from E-Commerce Website to payment gateway)
Receiving Encrypted Package and Ensuring no Tampering being done