执行apt-get update时报错：W: GPG error: http://security.kali.org kali/updates Release: The following signatures were invalid: KEYEXPIRED 1425567400 KEYEXPIRED 1425567400 KEYEXPIRED 1425567400
执行以下命令可以解决：sudo apt-key adv --keyserver pgp.mit.edu --recv-keys ED444FF07D8D0BF6
原文：http://my.oschina.net/jhdoctor/blog/470521