The network architecture of the system is based on TCP/IP. Where the environment is hostile and sensitive information is being transmitted between entities, encryption is always used. From the customer’s perspective, sensitive information includes cardholder information such as card numbers, cardholder names and expiry information. It also includes order fulfillment information such as shipping address, shipping date or method, or other delivery instructions. For merchants, sensitive information includes MAC generation keys, viewing on-line reports, and managing their account configuration.
For this reason, almost all Internet originated traffic to the acquirer system would be considered sensitive. Consequently, extensive use of SSL-enabled HTTP would be used by the acquirer system.
When sensitive information is sent over dedicated or secure channels, the option exists to allow the underlying network management to provide the requisite security. For this reason, if the acquirer has a dedicated connection to the Banknet system, then the transmission is done in the clear. The option exists to use VPN between the acquiring system and backend host system. Other options can be easily constructed.
The architecture specified above is very scalable.