debian apt-get update：public key 错误修复

   最近安装vanish想从apt自动安装，按照官方命令，添加vanish的源之后，发现竟然被GFW了……

   好吧，卸载，结果 apt-key del 之前添加的GPG key 之后， apt-get update  出现 这种错误

 

Reading package lists... Done

W: There is no public key available for the following key IDs:

7638D0442B90D010

W: There is no public key available for the following key IDs:

7638D0442B90D010

W: There is no public key available for the following key IDs:

9D6D8F6BC857C906

  google bing之后， 得到解答：

  

apt-get install debian-keyring debian-archive-keyring
apt-get update

  整个世界，清静了 :-D