msgstr ""
"Project-Id-Version: emailselfdefense ersion\n"
"POT-Creation-Date: 2018-06-23 10:15+0200\n"
-"PO-Revision-Date: 2019-03-02 19:31+0800\n"
+"PO-Revision-Date: 2019-03-08 00:17+0800\n"
"Last-Translator: Tom <hexuxin@foxmail.com>\n"
"Language-Team: \n"
"Language: zh_CN\n"
#. type: Content of: <html><head><title>
msgid ""
"Email Self-Defense - a guide to fighting surveillance with GnuPG encryption"
-msgstr "电子邮件自卫指南 —— 用 GnuPG 加密反抗监控"
+msgstr ""
+"Email Self-Defense - a guide to fighting surveillance with GnuPG encryption"
#. type: Attribute 'content' of: <html><head><meta>
msgid "GnuPG, GPG, privacy, email, Enigmail"
"4.0 许可协议 （或较新版本）</a>进行许可。下载<a href=\"http://agpl.fsf.org/"
"emailselfdefense.fsf.org/edward/CURRENT/edward.tar.gz\">爱德华自动回复机器人"
"的源代码</a> 由 Andrew Engelbrecht <sudoman@ninthfloor.org> 和 Josh "
-"Drake <zamnedix@gnu.org>编写，采用 GNU Affero General Public License 许"
-"可证进行许可。<a href=\"http://www.gnu.org/licenses/license-list."
+"Drake <zamnedix@gnu.org> 编写，采用 GNU Affero General Public License "
+"
许可证进行许可。<a href=\"http://www.gnu.org/licenses/license-list."
"html#OtherLicenses\">为什么要这些许可协议？</a>"
#. type: Content of: <html><body><footer><div><div><p>
"improving it, and making more materials, for the benefit of people around "
"the world taking the first step towards protecting their privacy.</strong>"
msgstr ""
-"<strong>请捐款以支持电子邮件加密指南。我们会一直改进它，使其充实，for the "
-"benefit of people around the world taking the first step towards protecting "
-"their privacy.</strong>"
+"<strong>请捐款以支持电子邮件加密指南。我们会一直改进它，使其充实，迈出保护自"
+"己隐私的第一步是人人受益的。</strong>"
#. type: Content of: <html><body><header><div><div><p><a>
msgid ""
"应该要求查看完整的公钥指纹，而不只是短 key ID。如果你认为所要签署人的公钥相当"
"重要，可以要求他出示身份证明，确保身份证上的姓名与公钥的姓名相符。在 "
"Enigmail 里，诚实地回答弹出窗口问题“你对签署的公钥确实属于那个名字的人，验证"
-"ç\9a\84ä»\94ç»\86程度？”"
+"ç\9a\84ä¸¥æ ¼程度？”"
#. type: Content of: <html><body><section><div><div><div><div><dl><dt>
msgid "Master the Web of Trust"
"除非你不想暴露身份（这还要求其他保护措施），没有理由不对每封信签名，无论是否"
"加密。除了允许 GnuPG 验证消息确实来自于你，签名是一种非侵入式的方式，提醒别人"
"你在使用 GnuPG，并对支持安全的通信表示支持。如果你经常给不熟悉 GnuPG 的人发送"
-"签名消息，在你的标准邮件签名中附上本指南的链接将会不错。"
+"签名消息，在你的标准邮件签名(the text kind, not the cryptographic kind)中附上"
+"本指南的链接将会不错。"
#. type: Attribute 'alt' of: <html><body><section><div><div><div><p><img>
msgid "Section 5: Use it Well (2)"
"type=\"hidden\" value=\"Edit:cancel\" name=\"_qf_default\" />"
msgstr ""
"<input type=\"text\" placeholder=\"输入你的邮箱地址…\" name=\"email-Primary"
-"\" id=\"frmEmail\" /> <input type=\"submit\" value=\"Add me\" name="
+"\" id=\"frmEmail\" /> <input type=\"submit\" value=\"添加\" name="
"\"_qf_Edit_next\" /> <input type=\"hidden\" value=\"https://emailselfdefense."
"fsf.org/zh-hans/confirmation.html\" name=\"postURL\" /> <input type=\"hidden"
"\" value=\"1\" name=\"group[25]\" /> <input type=\"hidden\" value=\"https://"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Bring Email Self-Defense to new people"
-msgstr ""
+msgstr "将本指南带给新人"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"To welcome them, make it easy to find your public key and offer to help with "
"encryption. Here are some suggestions:"
msgstr ""
+"理解并设置电子邮件加密对多数人是一项令人生畏的任务。为了欢迎他们，你要让你的"
+"公钥容易被找到，并提供加密上的帮助。以下是一些建议："
#. type: Content of: <html><body><section><div><div><div><ul><li>
msgid ""
"Lead an Email Self-Defense workshop for your friends and community, using "
"our <a href=\"workshops.html\">teaching guide</a>."
msgstr ""
+"使用我们的<a href=\"workshops.html\">教学指南</a>，为你的朋友和社区举办一场电"
+"子邮件加密研讨会。"
#. type: Content of: <html><body><section><div><div><div><ul><li>
msgid ""
"Remember to include your GnuPG public key fingerprint so they can easily "
"download your key."
msgstr ""
+"使用<a href=\"https://fsf.org/share?u=https://u.fsf.org/zb&t=Encrypt "
+"with me using Email Self-Defense %40fsf\">我们的分享页面</a>，给几个朋友撰写"
+"消息，要求他们加入加密邮件的队伍。记得附上你的 GnuPG 公钥指纹，这样他们可以容"
+"易地下载你的公钥。"
#. type: Content of: <html><body><section><div><div><div><ul><li>
msgid ""
"business cards. At the Free Software Foundation, we put ours on our <a href="
"\"https://fsf.org/about/staff\">staff page</a>."
msgstr ""
+"在所有显示你邮箱地址的地方，附上公钥指纹。一些好地方有：你的电子邮件签名(the "
+"text kind, not the cryptographic kind)，社交媒体简历，博客，网站，商业名片。"
+"在自由软件基金会，我们把把它放在了我们的<a href=\"https://fsf.org/about/staff"
+"\">雇员页面</a>。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Protect more of your digital life"
-msgstr ""
+msgstr "保护你的数字生活"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"wiki/Collection:Privacy_pack\"> the Free Software Directory's Privacy Pack</"
"a> and <a href=\"https://prism-break.org\">prism-break.org</a>."
msgstr ""
+"学习更多有关即时通讯、硬盘储存、在线分享的反监控技术，尽在 <a href=\"https://"
+"directory.fsf.org/wiki/Collection:Privacy_pack\">自由软件基金会隐私包</a> 和 "
+"<a href=\"https://prism-break.org\">prism-break.org</a>。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"hidden back doors. Check out the Free Software Foundation's <a href=\"http://"
"www.gnu.org/distros/free-distros.html\">endorsed versions of GNU/Linux.</a>"
msgstr ""
+"如果你正在使用 Windows， Mac OS 或 其他专有操作系统，我们建议你切换至自由邮件"
+"操作系统，诸如 GNU/Linux。攻击者通过隐藏后门入侵你的计算机会愈加困难。查看自"
+"由软件基金会<a href=\"http://www.gnu.org/distros/free-distros.html\">推荐的 "
+"GNU/Linux 发行版</a>。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Optional: Add more email protection with Tor"
-msgstr ""
+msgstr "可选：使用 Tor 增加对电子邮件的保护"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"apparatus alike. Using it simultaneously with GnuPG's encryption will give "
"you the best results."
msgstr ""
+"洋葱路由（Tor）网络以多重加密封装网络通讯，并在全球多次传递。如果使用得当，"
+"Tor 能够迷惑监控代理和全球监控设备。和 GnuPG 加密同时使用能够带给你最佳的安"
+"全。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"\">Torbirdy plugin</a> the same way you installed Enigmail, by searching for "
"it through Add-ons."
msgstr ""
+"要通过 Tor 在电子邮件程序收发邮件，需要安装 <a href=\"https://addons.mozilla."
+"org/en-us/thunderbird/addon/torbirdy/\">Torbirdy插件</a>，其步骤与安装 "
+"Enigmail 相同，在附加组建搜索即可。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"friends at the Electronic Frontier Foundation demonstrates how Tor keeps you "
"secure."
msgstr ""
+"在通过 Tor 检查邮件前，确保你了解<a href=\"https://www.torproject.org/docs/"
+"faq.html.en#WhatProtectionsDoesTorProvide\">权衡所涉及的安全问题</a>。我们在"
+"电子前哨基金会的朋友制作了 Tor 如何保证安全的<a href=\"https://www.eff.org/"
+"pages/tor-and-https\">信息图</a>。"
#. type: Attribute 'alt' of: <html><body><section><div><div><div><p><img>
msgid "Section 6: Next Steps"
-msgstr ""
+msgstr "Section 6: 下一步"
#. type: Content of: <html><body><section><div><div><div><p>
msgid "← <a href=\"index.html\">Return to the guide</a>"
-msgstr ""
+msgstr "← <a href=\"index.html\">返回指南</a>"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Make Email Self-Defense tools even better"
-msgstr ""
+msgstr "Make Email Self-Defense tools even better"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"campaigns@fsf.org\">campaigns@fsf.org</a> before you start, so that we can "
"connect you with other translators working in your language."
msgstr ""
+"<a href=\"https://libreplanet.org/wiki/GPG_guide/Public_Review\">留下够能提升"
+"本指南的反馈和建议</a>。我们欢迎译员，但我们要求你在开始前发邮件 <a href="
+"\"mailto:campaigns@fsf.org\">campaigns@fsf.org</a> 联系我们，这样我们可以和联"
+"系你和其他译员一起翻译成你的语言。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"gnupg.org/\">GnuPG</a> or <a href=\"https://www.enigmail.net/home/index.php"
"\">Enigmail</a>."
msgstr ""
+"如果你喜欢编程，你可以向 <a href=\"https://www.gnupg.org/\">GnuPG</a> 或 <a "
+"href=\"https://www.enigmail.net/home/index.php\">Enigmail</a> 贡献代码。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"To go the extra mile, support the Free Software Foundation so we can keep "
"improving Email Self-Defense, and make more tools like it."
msgstr ""
+"要走的更远，支持自由软件基金会，我们可以持续地提升本指南，并制作其他类似工"
+"具。"
#. type: Content of: <html><body><header><div><ul><li>
msgid "<a href=\"windows.html\" class=\"current\">Windows</a>"
"switch to a free software operating system like GNU/Linux. Learn more about "
"free software at <a href=\"https://u.fsf.org/ys\">fsf.org</a>."
msgstr ""
+"本指南需要安装<a href=\"https://www.gnu.org/philosophy/free-sw.html\">自由许"
+"可的</a>软件；它是完全透明的，任何人都可以复制它，并制作自己的版本。这使得它"
+"比专有软件（比如 Windows）更难受到监控。为了你免受监控，我们推荐你换用像 GNU/"
+"Linux 这样的自由软件操作系统。你可以在 <a href=\"https://u.fsf.org/ys\">fsf."
+"org</a> 上了解更多有关自由软件的信息。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "<em>Step 1.b</em> Get GnuPG by downloading GPG4Win"
-msgstr ""
+msgstr "<em>Step 1.b</em> 下载 GPG4Win 获取 GnuPG"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"whenever asked. After it's installed, you can close any windows that it "
"creates."
msgstr ""
+"GPG4Win 是一个包含 GnuPG 的软件包。<a href=\"https://www.gpg4win.org/\">下载"
+"</a>并安装它，无论提示什么都选择默认选项。安装后，你可以关闭程序创建的窗口。"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"There are major security flaws in versions of GnuPG provided by GPG4Win "
"prior to 3.1.2. Make sure you have GPG4Win 3.1.2 or later."
msgstr ""
+"在 GPG4Win 3.1.2 前的版本存在重大安全漏洞。请确保安装的是 GPG4Win 3.1.2 及其"
+"之后的版本。"
#. type: Content of: <html><head><title>
msgid "Email Self-Defense - Teach your friends!"
-msgstr ""
+msgstr "Email Self-Defense - Teach your friends!"
#. type: Content of: <html><body><header><div><ul><li>
msgid "<a href=\"workshops.html\" class=\"current\">Teach your friends</a>"
-msgstr ""
+msgstr "<a href=\"workshops.html\" class=\"current\">研讨会</a>"
#. type: Content of: <html><body><header><div><div><div><p>
msgid ""
"world take the first step towards protecting their privacy with free "
"software."
msgstr ""
+"我们想让本指南翻译成多国语言，并制作移动设备版本的加密版本。请捐款，帮助全世"
+"界的人们用自由软件保护他们隐私的第一步。"
#. type: Content of: <html><body><header><div><div><p><a>
msgid ""
#. type: Attribute 'alt' of: <html><body><header><div><div><p><a><img>
msgid "View & share our infographic →"
-msgstr ""
+msgstr "查看并分享我们的信息图 →"
#. type: Content of: <html><body><header><div><div><p>
msgid ""
"GnuPG to send and receive encrypted email, you're a perfect candidate for "
"leading a workshop!"
msgstr ""
+"</a>理解并设置电子邮件加密对多数人是一项令人畏惧的任务。这就是为什么在帮助朋"
+"友使用 GnuPG 加密时，你的存在至关重要。即便只有一个人到场，那么也至少有一个人"
+"开始使用加密了。你有能力帮助你的好友保护他们电子情书的隐私，告诉他们自由软件"
+"的重要性。如果你使用 GnuPG 收发加密邮件，那么你是举办研讨会的最佳人选。"
#. type: Attribute 'alt' of: <html><body><section><div><div><p><img>
msgid "A small workshop among friends"
-msgstr ""
+msgstr "小研讨会"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#1</em> Get your friends or community interested"
-msgstr ""
+msgstr "<em>#1</em> 让你的朋友和社区感兴趣"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"might even hear the classic \"if you've got nothing to hide, you've got "
"nothing to fear\" argument against using encryption."
msgstr ""
+"如果你听过朋友抱怨他们缺乏隐私，询问他们是否愿意出席 Email Self-Defense 研讨"
+"会。如果你的朋友并未抱怨过，你可能需要说服他们。你甚至可能会听到经典的“光明磊"
+"落的人无可畏惧”的论据来反对使用加密。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"to learn GnuPG. Mix and match whichever you think will make sense to your "
"community:"
msgstr ""
+"下面是你可以用来解释的为什么值得学习 GnuPG 要点。并结合自己的观点，为什么它对"
+"你的社区有意义："
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Strength in numbers"
-msgstr ""
+msgstr "众擎易举"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"makes it harder for surveillance systems to single out those that can't "
"afford to be found, and shows solidarity with those people."
msgstr ""
+"每个使用加密反抗大规模监控的人，同时让对方更容易反抗。普遍使用强加密有着多种"
+"强大的效果：这意味着那些最需要隐私的人，潜在的告密者和活动认识更有可能接触到"
+"加密。越多的人对越多的事物使用加密的同时，监控系统查找信息的成本会无法负担。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "People you respect may already be using encryption"
-msgstr ""
+msgstr "你所尊敬的人可能已经在使用加密"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"make a list of people and organizations who use GnuPG whom your community "
"will likely recognize."
msgstr ""
+"许多记者，告密者，活动人士以及研究者在使用 GnuPG，因此你的喷有可能不知不觉中"
+"听说过几位在使用它的人了。你可以搜索 \"BEGIN PUBLIC KEY BLOCK\" 加上关键词，"
+"制作出一个在使用 GnuPG 人物和组织列表，其中你的社区能够认出他们。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Respect your friends' privacy"
-msgstr ""
+msgstr "尊重朋友的隐私"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"agent, for that matter!) feels the same way. Show your friends respect by "
"encrypting your correspondence with them."
msgstr ""
+"没有办法判断是否存在隐私敏感的通信。因此，不要因为你觉得发给发给朋友的信件无"
+"关紧要而假定它不隐私敏感。"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "Privacy technology is normal in the physical world"
-msgstr ""
+msgstr "隐私技术在现实世界很常见"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"for granted as ways of protecting our privacy. Why should the digital realm "
"be any different?"
msgstr ""
+"在现实世界，我们拉上百叶窗，信封包装以及关闭房门来作为保护我们隐私的手段。为"
+"什么数字世界要有不同？"
#. type: Content of: <html><body><section><div><div><div><h3>
msgid "We shouldn't have to trust our email providers with our privacy"
-msgstr ""
+msgstr "我们不应当信任邮件服务提供商给予的隐私"
#. type: Content of: <html><body><section><div><div><div><p>
msgid ""
"protect your privacy and security. To be empowered digital citizens, we need "
"to build our own security from the bottom up."
msgstr ""
+"有些邮件提供商非常值得信赖，但绝大多数提供商并没有保护你隐私和安全的动机。我"
+"们需要从“下层建筑”建立起自己的安全，才能成为数字公民。"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#2</em> Plan The Workshop"
-msgstr ""
+msgstr "<em>#2</em> 计划一场研讨会"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"Enigmail-compatible email client before the event. Direct them to their "
"email provider's IT department or help page if they run into errors."
msgstr ""
+"你和至少一位感兴趣的朋友约好时间，便可以筹备研讨会了。告诉与会者带上他们的计"
+"算机和 ID（用于相互签名）。预先准备好骰子，这样你的朋友用 Diceware 方法生成密"
+"码会方便很多。确保你定的地点能方便上网，并做好研讨会当天断网的预案。图书馆，"
+"咖啡店以及社区中心都是合适地点之选。试着让与会者在会前安装 Enigmail 兼容的邮"
+"件客户端。如果他们遇到问题，直接联系邮件提供商的 IT 部门。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"Estimate that the workshop will take at least forty minutes plus ten minutes "
"for each participant. Plan extra time for questions and technical glitches."
msgstr ""
+"预计研讨会将持续四十分钟，每多一位与会者将额外花费十分钟。请准备好额外的时间"
+"应对问题和技术故障。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"facilitator to participant ratio high by recruiting more facilitators, or by "
"facilitating multiple workshops. Small workshops among friends work great!"
msgstr ""
+"研讨会的成功取决于了解每一位与会者的背景并满足他们的需求。研讨会应当尽可能的"
+"小，每位与会者都能受到个性化的指导。如果想要参与的人超出了你所能应付的范围，"
+"那么保持较高的主持者与与会者之比，或者举办多场研讨会。小型的研讨会往往效果更"
+"好。"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#3</em> Follow the guide as a group"
-msgstr ""
+msgstr "<em>#3</em> 分组学习指南"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"afterwards for people that had trouble grasping the concepts, or those that "
"grasped them quickly and want to learn more."
msgstr ""
+"分小组完成 Email Self-Defense 指南中的步骤。具体而微地解释步骤，但确保不要超"
+"过与会者理解的上限。对于技术娴熟的与会者，可以大大提高指示的难度。确保组内成"
+"员完成了一步后再进行下一步。考虑后续为理解概念有困难的人，迅速掌握又想学到更"
+"多新知识的人提供第二次辅导研讨会。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"sign each other's keys. At the end, make sure to remind people to safely "
"back up their revocation certificates."
msgstr ""
+"在本指南的 <a href=\"index.html#section2\">Section 2</a> ，确保每一位与会者都"
+"上传公钥到相同服务器（有时密钥服务器之间同步有延迟），他们可以立即下载各自的"
+"公钥。在 <a href=\"index.html#section3\">Section 3</a>，让与会者有时间相互发"
+"送测试邮件，而不是给爱德华发邮件。相似地，在 <a href=\"index."
+"html#section4\">Section 4</a>，鼓励与会者相互对彼此公钥签名。最后，提醒他们将"
+"吊销证书确保保存在安全的地方。"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#4</em> Explain the pitfalls"
-msgstr ""
+msgstr "<em>#4</em> 说明容易犯的错误"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"icon before hitting send, and that subjects and timestamps are never "
"encrypted."
msgstr ""
+"提醒与会者，加密只有在明确使用时才有效；他们无法向未设置加密的人发送加密信"
+"件。同时提醒与会者，在点击发送前再次检查加密图标，以及邮件主题和时间戳从来不"
+"会被加密。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"bulletin/2013/fall/how-can-free-software-protect-us-from-surveillance"
"\">meaningfully resist invasions of our digital privacy and autonomy</a>."
msgstr ""
+"解释<a href=\"https://www.gnu.org/proprietary/proprietary.html\">运行专有操作"
+"系统的危险</a>，并倡导自由软件，因为没有后者，我们就无法<a href=\"https://"
+"www.fsf.org/bulletin/2013/fall/how-can-free-software-protect-us-from-"
+"surveillance\">行之有效地对抗对我们数字隐私和自治的侵犯</a>。"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#5</em> Share additional resources"
-msgstr ""
+msgstr "<em>#5</em> 分享额外资源"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"documentation and mailing lists. Many GNU/Linux distribution's Web sites "
"also contain a page explaining some of GnuPG's advanced features."
msgstr ""
+"GnuPG 的高级操作太复杂以至于无法在一场研讨会上教授完毕。如果与会者想了解更"
+"多，告诉他们本指南中有进阶章节，或者考虑参加下一场研讨会。你也可以分享 <a "
+"href=\"https://www.gnupg.org/documentation/index.html\">GnuPG</a> 和<a href="
+"\"https://www.enigmail.net/documentation/index.php\">Enigmail</a> 的官方文档"
+"和邮件列表。许多 GNU/Linux 发行版也提供了一些对 GnuPG 高级功能的说明页面。"
#. type: Content of: <html><body><section><div><div><h2>
msgid "<em>#6</em> Follow up"
-msgstr ""
+msgstr "<em>#6</em> 坚持到底"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
"week after the event, reminding them to try adding their public key ID to "
"places where they publicly list their email address."
msgstr ""
+"确保所有人在离开前交换了电子邮箱地址和公钥指纹。通过互相发送邮件，鼓励与会者"
+"继续使用 GnuPG。在活动结束一周后，给他们各自发送一封加密邮件，提醒他们将公钥 "
+"ID 放置在他们公开邮箱地址的地方。"
#. type: Content of: <html><body><section><div><div><p>
msgid ""
projects / enc.git / commitdiff