Specifically, once the customer has filled in payment information on
an online merchant?s web site, what happens ?

Where does the data go ? 

Why does it go there (where is the routing table) ? 

In what format is it sent (what are the data fields, what size are they) ?

Is it encrypted ? Are there other security measures ?

I would like information to be in as much detail as possible,

Thanks.

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Clarification of Question by elp-ga on 28 Feb 2006 04:28 PST

Sorry, I need to add that: I would need to know this for Visa,
Mastercard, American Express and Discover payments. In addition, when
security measures kick in example:verified by visa, mastercard
securecode, we would need to know what changes in the process. Does
the info go somewhere else ? If so where ?

And finally, I would like to know what happens to the credit card
numbers when Discover modifies them. Is everything modified ? Do they
maintain the first digits constant (the name of the card issuer), does
it still contain error checking ?