尝试安装任何东西时出现“不受信任的软件包可能会危及系统的安全性”
我刚刚在新电脑上安装了Ubuntu 10.04。 我正在尝试安装我需要的应用程序（我的旧计算机坏了，我必须将其发送给服务）。 我已经设法安装texlive，但后来我无法安装任何其他东西。 我想安装的所有软件都是我之前在旧计算机上成功安装的软件（使用相同版本的Ubuntu）。 我不明白为什么终端会发出这个警告（抱歉，终端说英语半，半波兰语，但我希望它已经足够了）：
maria@marysia-ubuntu:~$ sudo aptitude install emacs Czytanie list pakietów... Gotowe Budowanie drzewa zależności Odczyt informacji o stanie... Gotowe Reading extended state information Initializing package states... Gotowe The following NEW packages will be installed: emacs emacs23{a} emacs23-bin-common{a} emacs23-common{a} emacsen-common{a} 0 packages upgraded, 5 newly installed, 0 to remove and 0 not upgraded. Need to get 23,9MB of archives. After unpacking 73,8MB will be used. Do you want to continue? [Y/n/?] Y WARNING: untrusted versions of the following packages will be installed! Untrusted packages could compromise your system's security. You should only proceed with the installation if you are certain that this is what you want to do. emacs emacs23-bin-common emacsen-common emacs23-common emacs23 Do you want to ignore this warning and proceed anyway? To continue, enter "Yes"; to abort, enter "No" 我也试图安装其他编辑器，结果相同。 当我决定我可能确定我知道我要安装的软件包是安全的时候，我终于输入了“是”。 安装成功结束，但编辑器不理解.tex文件（并且已知.tex文件本身很好）：
this is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian) restricted \write18 enabled. entering extended mode (./Szarfi.tex ! Undefined control sequence. l.2 \documentclass {book} ?
更重要的是，我意识到在Synaptic Manager中没有任何标记为Canonical支持的软件包….
有小费吗？ 提前致谢。
PS
使用update前的apt源：
maria@marysia-ubuntu:~$ cat /etc/apt/sources.list #deb cdrom:[Ubuntu 10.04.2 LTS _Lucid Lynx_ - Release i386 (20110211.1)]/ lucid main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://pl.archive.ubuntu.com/ubuntu/ lucid main restricted deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates main restricted deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates main restricted ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://pl.archive.ubuntu.com/ubuntu/ lucid universe deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid universe deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates universe deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates universe ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://pl.archive.ubuntu.com/ubuntu/ lucid multiverse deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid multiverse deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates multiverse deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates multiverse ## Uncomment the following two lines to add software from the 'backports' ## repository. ## NB software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. # deb http://pl.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse # deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu lucid partner # deb-src http://archive.canonical.com/ubuntu lucid partner deb http://security.ubuntu.com/ubuntu lucid-security main restricted deb-src http://security.ubuntu.com/ubuntu lucid-security main restricted deb http://security.ubuntu.com/ubuntu lucid-security universe deb-src http://security.ubuntu.com/ubuntu lucid-security universe deb http://security.ubuntu.com/ubuntu lucid-security multiverse deb-src http://security.ubuntu.com/ubuntu lucid-security multiverse maria@marysia-ubuntu:~$
使用update ，几乎没问题。 我已经设法安装了3个应用程序（texlive，texworks和ekg），Synaptic显示了“由Cannonical支持”的图标。 但是连接问题仍然存在。
我已连接到互联网，我可以使用聊天，但有时我无法打开任何网页。 我不确定这是否是同一问题的一部分，或者如果一个问题得到解决，另一个问题我应该写一个单独的post。
使用更新后的apt源列表：
maria@marysia-ubuntu:~$ cat /etc/apt/sources.list #deb cdrom:[Ubuntu 10.04.2 LTS _Lucid Lynx_ - Release i386 (20110211.1)]/ lucid main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://pl.archive.ubuntu.com/ubuntu/ lucid main restricted deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates main restricted deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates main restricted ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://pl.archive.ubuntu.com/ubuntu/ lucid universe deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid universe deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates universe deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates universe ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://pl.archive.ubuntu.com/ubuntu/ lucid multiverse deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid multiverse deb http://pl.archive.ubuntu.com/ubuntu/ lucid-updates multiverse deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-updates multiverse ## Uncomment the following two lines to add software from the 'backports' ## repository. ## NB software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. # deb http://pl.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse # deb-src http://pl.archive.ubuntu.com/ubuntu/ lucid-backports main restricted universe multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu lucid partner # deb-src http://archive.canonical.com/ubuntu lucid partner deb http://security.ubuntu.com/ubuntu lucid-security main restricted deb-src http://security.ubuntu.com/ubuntu lucid-security main restricted deb http://security.ubuntu.com/ubuntu lucid-security universe deb-src http://security.ubuntu.com/ubuntu lucid-security universe deb http://security.ubuntu.com/ubuntu lucid-security multiverse deb-src http://security.ubuntu.com/ubuntu lucid-security multiverse maria@marysia-ubuntu:~$
似乎发生了变化，但这是我唯一能理解的。
谢谢。
尝试更新数据库
sudo apt-get update
如果您之后仍然看到警告消息，请提供存储库列表
grep -IRH '^deb ' /etc/apt/
如果您刚安装了Ubuntu，并且未添加任何存储库，请更新软件包列表并升级软件包：
sudo apt-get update sudo apt-get upgrade
建议在安装其他软件包之前先更新系统（至少在首次安装后）。 裁谈会的内容可能已经过时。
我不是100％肯定，但看起来你错过了一堆gpg键。 要解决这个问题，我会安装launchpad-getkeys，它将导入系统上所有缺失的密钥。
要安装launchpad-getkeys，你需要先添加一个ppa – 什么是ppa以及如何使用它们 ppa行是ppa:nilarimogard/webupd8
然后你可以先安装launchpad-get键输入
sudo apt-get update
那么这个
sudo apt-get install launchpad-getkeys
最后使用此命令运行
sudo launchpad-getkeys
最后，我会在导入密钥后运行另一个更新。
sudo apt-get update
希望这可以帮助