【介绍】什么是visa上的credit card security code

在遇到用visa支付时  大家可能遇到过要输入  credit card security code  
8 E5 M+ U/ @% w: n, r) v% R1 i' h; t5 N3 f
8 c- j# W# m. |
- y" @/ s4 J, B# T4 D' M
6 _' O) Z1 N9 w  |9 K  b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。) Q* ]2 S- J% j, X  `' A

: ?* m6 b5 M2 a% E- i7 @: E3 e2 U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。/ F/ ^2 b( F5 o) Y0 M# z9 n

' U0 q& w4 B" O8 }" f" J
4 r* T0 Z. \1 h- ^: N6 o; n注2：
3 u8 o7 O; i5 g. \; S注释原文
2 c( d6 x, f# I+ R& iWhat is the Security Code?4 [2 x' B1 m' u2 g7 }! H
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.2 k! B  k( w5 Q; a
' A( ^6 u2 ?4 A2 ?
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.
' ~9 j3 K& q+ T, K$ N# {! {7 @" Z) S# [
# r7 e2 z5 V: d6 }  B" X