生活中为了保障自己的权益、证实自己的身份,成年人都有一个身份证,谨防“假冒”。可是到了网上用什么来证明自己呢?又如何证明别人的网上身份呢?你收到的邮件一定是你的好朋友发来的吗?你又用什么向别人证明你发的邮件没有被别人修改或就是你发的呢?如何保证你发出的邮件只有你希望的人能够看到?由于越来越多的人通过电子邮件发送机密 In order to protect their own rights and interests in life, to confirm their identity, adults have an ID card, beware of “counterfeit.” But what is the use of online to prove themselves? How to prove someone else’s online identity? You received the mail must be sent to your friends? And what you use to prove to others that your email has not been modified by others Or is it your hair? How to ensure that you send the e-mail only you want to see? As more and more people by e-mail to send confidential