豆瓣 douban.com
1.34K subscribers
177K photos
37.1K videos
7.07K files
164K links
豆瓣最受欢迎的书评 豆瓣最受欢迎的影评 豆瓣最受欢迎的乐评
豆瓣网 WikiHow Skills Quora Books Movies Music
豆瓣 @doubancom
知乎 @zhihubaidu
微信 @weixinCN
谣言 @TruthRumors
微博 @weibonews
Download Telegram
How the FBI Extracted Deleted Signal Messages From a Defendant's iPhone

You might have heard about Signal, the encrypted chat app the U.S. government infamously used to discuss war plans last year. (Yikes.) But while the app is no alternative to a dedicated SCIF, it is a good option for the rest of us to communicate more securely. Signal uses end-to-end encryption (E2EE), which, very simply, means that messages are "scrambled" in transit, and can only be "unscrambled" by the sender and the recipient or recipients. If you're in a Signal chat, you'll be able to read incoming messages just like you would any other chat app—if you're an attacker, and intercept that message, all you'll find is a jumble of code.

E2EE makes it difficult for anyone without your unlocked device (or your unlocked Signal app) to read your Signal message—difficult, not impossible. That's part of the reason the chat app is no option for government officials (though no third-party chat app could be). But it's also a good reminder that no matter who you are, your secure chats are not impervious to outside forces. If someone wants to break into your chats, they might find a way to do so.

The FBI recently recovered deleted Signal messages from an iPhone

Case in point: As reported by 404 Media, the FBI recently extracted incoming Signal messages from a defendant's iPhone. The user had even deleted the app off their device, which only added another hurdle into the investigators' goals. You would think by deleting the app itself, your encrypted messages would be protected. As it turns out, however, the FBI didn't need to access the Signal app at all. While they weren't able to retrieve the defendant's outgoing messages, they were able to scrape incoming messages from the iPhone's push notification database. (I've been covering iPhones for nearly a decade, and I wasn't aware that iOS even had a push notification database—though I suppose it makes sense, given that alerts exist in Notification Center until you manually open or dismiss them.)

This revelation comes from a case involving a group allegedly vandalizing property and setting off fireworks at the ICE Prairieland Detention Facility. One officer involved in the altercation was shot in the neck. According to a supporter of the defendants in this case who took notes during the trial, the court learned that any app that has permission to show previews and alerts on the Lock Screen will save those previews to the internal memory of the user's iPhone. As such, the FBI was able to obtain messages the defendant had received, even though those messages were set to disappear in the app, and the app had been cleared from the device.

Again, this is not a security hole exclusive to Signal: Any app that displays an alert on your Lock Screen has this vulnerability. The FBI probably had plenty of other notifications to sift through as well, from any app the defendant had running on their iPhone. Think about the alerts you might have sitting in Notification Center right now: texts, reminders, news bulletins, purchases, DMs, etc. All of that could be fodder for anyone with the surveillance tech to root through your iPhone—locked or not.

How to stop this from happening to you

If you use Signal, you actually have an advantage here, now that you know about this vulnerability. Signal has a setting that blocks the content of messages from appearing in their notifications. That way, even if someone accesses your alerts, all they'll see is you received a Signal message—not who sent it or what it contains.

To turn it on, open Signal, tap your profile in the top-left corner, then hit "Settings." Under Notification Content, choose "No Name or Content" to block all data to the alert. You can compromise here and choose "Name Only" if you want to know who a message is from before you open it—just remember, an intruder may also see you received a message from that person if they scrape your iPhone's notifications.

via Lifehacker (author: Jake Peterson)
关于“经典”的一本经典:读《重读商业经典》 (评论: 重读商业经典)

isaachan评论: 重读商业经典

评价: 推荐

via 豆瓣最受欢迎的书评 (author: isaachan)
李静睿:写家乡自贡,是最自然的选择 (评论: 刮风下雨)

瓦片外婆评论: 刮风下雨

评价: 力荐

via 豆瓣最受欢迎的书评 (author: 瓦片外婆)
book-default-lpic.gif
1.2 KB
感受她人的痛苦并不需要认同 (评论: Et la joie de vivre)

野柚子Timo评论: Et la joie de vivre

评价: 推荐

via 豆瓣最受欢迎的书评 (author: 野柚子Timo)
身体的衰老、疼痛与局限 (评论: 身体,再来)

龙骑士兰斯洛特评论: 身体,再来

评价: 力荐

via 豆瓣最受欢迎的书评 (author: 龙骑士兰斯洛特)
重读经典,不仅是向回望,更是为向前走 (评论: 重读商业经典)

无斋公子评论: 重读商业经典

评价: 力荐

via 豆瓣最受欢迎的书评 (author: 无斋公子)
成都入坑听完了赵雷的所有歌 以下是一些觉得封神的歌词 (评论: 成都)

豆友17Q67r-4r4评论: 成都

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: 豆友17Q67r-4r4)
叹云兮叹宿命兮 (评论: 叹云兮)

豆友17Q67r-4r4评论: 叹云兮

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: 豆友17Q67r-4r4)
青春伤痕的东亚盯鞋,也许这是最本真纯粹的蘑菇帝国——专辑推荐76.渦になる-きのこ帝国 (评论: 渦になる)

へ星评论: 渦になる

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: へ星)
杰伦新专《太阳之子》乐评,兼过往专辑纵评 (评论: 太阳之子)

温柔的异乡评论: 太阳之子

评价: 还行

via 豆瓣最受欢迎的乐评 (author: 温柔的异乡)
流行音乐天花板?多元素加成下的加拿大摇滚究竟有多好听——专辑推荐78.Blue Rev- Alvvays (评论: Blue Rev)

へ星评论: Blue Rev

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: へ星)
如果天堂有音乐,那么我想一定会有这张专辑——专辑推荐79.Heaven or Las Vegas-Cocteau Twins (评论: Heaven or Las Vegas)

へ星评论: Heaven or Las Vegas

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: へ星)
如果天堂有音乐,那么我想一定会有这张专辑——专辑推荐79.Heaven or Las Vegas-Cocteau Twins (评论: Heaven or Las Vegas)

へ星评论: Heaven or Las Vegas

评价: 力荐

via 豆瓣最受欢迎的乐评 (author: へ星)