When updating the Debian based system, it may happens that the apt-get displays an error message like:
当更新的基于Debian的系统，它可能发生的apt-get显示一个错误信息，如：
# apt-get update
W: GPG error: maverick Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A9BF3BB4E5E17B5
This is a new feature of the apt-get system that guarantee the authenticity of servers for updating Debian.
这是一个新的功能，保证服务器的真实性更新Debian的apt-get的系统中。
Solution 解决
Simply type the following commands, taking care to replace the number of the key that displayed in the error message:
只需键入以下命令，更换为显示在你错误消息中的 PUBKEY
# gpg --keyserver pgpkeys.mit.edu --recv-key 5A9BF3BB4E5E17B5
# gpg -a --export 5A9BF3BB4E5E17B5 | apt-key add -
当更新的基于Debian的系统，它可能发生的apt-get显示一个错误信息，如：
# apt-get update
W: GPG error: maverick Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A9BF3BB4E5E17B5
This is a new feature of the apt-get system that guarantee the authenticity of servers for updating Debian.
这是一个新的功能，保证服务器的真实性更新Debian的apt-get的系统中。
Solution 解决
Simply type the following commands, taking care to replace the number of the key that displayed in the error message:
只需键入以下命令，更换为显示在你错误消息中的 PUBKEY
# gpg --keyserver pgpkeys.mit.edu --recv-key 5A9BF3BB4E5E17B5
# gpg -a --export 5A9BF3BB4E5E17B5 | apt-key add -