网申时如何填visa信用卡上的security code

在遇到用visa支付时，大家可能遇到过要输入credit card security code

在签名的那一条上，应该印有一个三位数的数字。不是卡号的后三位，既然叫security number,就是为了保险安全使用visa卡啊，银行是不可能知道这个信息的，就是知道也不可能透露。

注1：工行规定，登陆境外银行网上划账，需要开通授权功能的。

英文原文：

What is the Security Code?

It is an important new Internet security feature that now appears on the back of most Visa/MasterCard and Discover cards, and on the front of American Express cards. This new code is a three or four-digit number which provides a cryptographic check of the information embossed on the card.

The security code helps validate that the customer placing the online order actually has the credit card in his/her possession, and that the credit/debit card account is legitimate.