Regarding the difference between CVV2 and Verified by VISA:
CVV2 is a system that ensures the purchaser has physical possession of the credit card by virtue of the imprinted code unique to that card.
Verified by VISA is a system whereby the consumer can log into VISA's website and register their card and obtain a PIN of their choosing. If a merchant participates in VBV, this PIN will be required to complete the purchase. It essentially eliminates the possibility of charges to a stolen credit card or other unauthorized use. For more information on Verified by VISA, visit:
http://www.usa.visa.com/business/mer...h2_/index.html