Stop Blurring Sensitive Information in Screenshots
Want to hide parts of a screenshot that contain personal information, such as your home address or credit card number? It’s a good idea, but you should stop using tools that pixelate, blur, or use other cool effects like swirls to hide this information – it’s almost like luring strangers into trying to see what’s been edited, and it’s a lot easier to do than most people can guess. A new tool called Unredacter does just that.
Unredacter can easily reveal text hidden with crude effects such as pixelation. It’s a free tool available on GitHub for everyone and was created to raise awareness about the dangers of posting poorly hidden text in screenshots ( read this post on the Unredacter creators blog to see how it works). If such a tool is readily available to the public for free, it is safe to assume that attackers can easily access the information published in the screenshots.
The next time you want to share a screenshot online, use the best tools to hide your personal information. The safest tool for most people is solid colored blocks. You can quickly draw a solid color rectangle over sensitive information to make it nearly impossible to decipher. On Windows and Mac, any free image editor such as MS Paint or Preview can handle this task. All you have to do is draw any shape like a circle or a rectangle and fill it with a solid color. Both Android and iPhone have built-in screenshot editing tools that can help you do the same.
If nothing else, you can also put a bunch of emoticons on sensitive information. It’s safe if you’re careful not to expose any part of the text, which means you’ll be spamming emoji in the screenshot.
While we’ve talked mostly about text so far, the same problem persists with photographs. You can clearly see blurry or pixelated faces with some tools, so it’s always best to use solid colored blocks to hide them. Apps like MaskerAid make it easy to add emoji to people’s faces. If you’re sharing a photo of a stranger’s face online, it’s a good idea to use one of these tools to hide their face before posting their photo.