V3/V4卡也为公话卡,它是通过特定的STK处理流程和相关功能设置,实现对移动公话话机德认证,并以此禁止在普通GSM终端中使用.3DES算法就用于公话加密卡-3DESsecret Visua C++ used TDMCDMA （3G）SIM Tookit application。 To perform the UPDATE FDN data (as described in the procedure below), the default FDN UICC may be used.