Get:1 http://old.kali.org/kali sana InRelease [20.3 kB]
Err:1 http://old.kali.org/kali sana InRelease
The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org>
Get:2 http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease [30.5 kB]
Err:2 http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease
The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org>
Reading package lists... Done
W: GPG error: http://old.kali.org/kali sana InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org>
E: The repository 'http://old.kali.org/kali sana InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org>
E: The repository 'http://http.kali.org/kali kali-rolling InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
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解决办法:
wget -q -O - archive.kali.org/archive-key.asc | apt-key add