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Tell HN: Zelensky is blurring -not blanking- sensitive info in a video with Musk
52 points by giuliomagnifico on March 7, 2022 | hide | past | favorite | 35 comments
According to this video shared by Zelensky Facebook page: https://www.youtube.com/watch?v=HucqNfL1oYA (YouTube link for those who don’t use FB).

Surely the documents in the video and his phone aren’t decisive for the war, but since a text inside an image can be easily deblurred using -lots of- ML tools available, it isn’t a bit unsafe to share video like this?

Maybe for a video is different but, if deblurring an image is not trouble for me, I don’t think it’s a hard trouble for the Russian IT guys to deblur a video.

Someone should alert the Zelensky’s social staff it, or I’m missing something?




I can barely count how many lines the text message has, and you think a ML tool would be able to decipher it? This is an impossible task, the text information is completely lost on the blur


A gaussian blur is a point-wise multiplication in Fourier space. If you know the filter, you can technically reverse it with a point-wise division. Even noise can be controlled for by using optimization techniques to recover the correct divisor. It doesn't at all surprise me that you could train up an ML model to recover the original.


I'm not saying it's impossible, but remember that information is lost in the blur. It's as if you posterized an image to two colors - just because you know the algorithm doesn't mean you can revert the process.


This is an induction based argument though. Because information is lost (is it?), it's probably impossible to reverse.

Look at this example image,do you think it would be possible to restore?

https://kbpdfstudio.qoppa.com/wp-content/uploads/sample-text...

Also this depixelated text:

https://www.hackread.com/wp-content/uploads/2022/02/new-unde...


I think I made a mistake by saying "information is lost", rather than "some information is lost" - clearly, some information remains, and as I started my comment, I'm not saying it's impossible.

In fact I share the sentiment that seemingly irreversible things can often be reversed, we just don't have the technology to do so. However my enthusiasm took a huge hit once I learned how the technology we have usually operates: for example the photo sharpeners enhance photos by creating faces different than the actual original pre-blur faces. Just got an idea I have to test eventually, how close would those "recovered" images be to the algorithm input, if the blur was reapplied...

Your first example (recovering text from photo) is impressive, but the blur is clearly one that blurs as little as possible to make the text unreadable. I think if you increased the blur just slightly, too much information would get lost. I also wonder what was the resolution of the image and what was the color depth (was that a JPEG or RAW format?) Without the ability to inspect and repeat the process I'll remain skeptical about de-blurring.


If blur is a strictly mathematical and deterministic operation, which it often is, then reversing it should be possible. Remember that a pixel is only a bunch of numbers. Even non-mathematic blur should be possible...

And the reason for that is small variations in the blur still exist and give away (with varying amounts of certainty) which shapes could be put together to form the resulting blurry pattern.

But yes, information is actually lost in the sense that more than one image can potentially be the used to generate the same blurry pattern, and there is also limited precision to each pixel.


Just floating the point: Not all mathematical, deterministic operations are invertible.


I think it's still prudent to move the task from "probably impossible" to "definitely impossible".


It's more than enough to infect him with 0days on imessage/whatsapp etc. That's how Bezos got hacked. All they needed was his phone number and using NSO's Pegasus they got full control over his phone. In the case of Zelensky it's even worse, he probably discusses war tactics all day every day. An adversary having that information is equivalent to breaking the Enigma in WW2.


Bezos didn't get hacked. His girlfriend's brother leaked the texts.


https://www.wired.com/story/bezos-phone-hack-mbs-saudi-arabi...


> An April 2021 Bloomberg investigation found that AMI's Chief Content Officer Dylan Howard, National Enquirer editor James Robertson, and Andrea Simpson, an L.A.-based reporter for AMI all stated in federal court that Michael Sanchez was the sole source of all the information and compromising material they received during the investigation and that Saudi Arabia was not involved.

I guess it's up for debate and both things may be true. https://en.wikipedia.org/wiki/Jeff_Bezos_phone_hacking


Think about what you are saying.

Do you really think a threat actor with those resources needs a blurred image to get his phone number?


How can we reach out to Zelensky and tell him?


Probably easiest through his IMDB page https://www.imdb.com/name/nm3305952/


have you tried contacting one of his partners mentioned in the panama papers :D


Email, call your Ukrainian embassy. DM them on Twitter. Tons of options.


In this case calling the embassy looks reliable (if you can stand the probably long queues), because the middlemen on the way will recognize that this matters. But most of the time, I'm skeptical the famous person you're trying to reach will ever see your email or tweet, nor will your call be promoted.


I have no idea sincerely. I think by writing to the ministry of IT, but I doubt it will reply…


I don't think there's any cause for concern. Zelensky is likely receiving real-time intelligence and advice from NSA, CIA, GCHQ, and much more. If there was any issue with this video, they would have already taken steps to ensure the information is stale and this doesn't happen again.


I'll be impressed if you can get anything out of that video

If so, which tools would you recommend?

I can't even get decent OCR


I will not tell you how to do anything that can harm Ukrainian people.


Any other blurred video is fine too. I've actually experimented with a couple of solutions but nothing really works. You can remove motion blur at best, certainly not reading blurred text.

[Not] asking for a comrade


Thanks, good to know that the text can't be easily deblurred!


But you just did as you're the OP?


By the time they unblur it, all the info in there becomes stale.


Smart Deblur[1] is probably one of the best publicly available tools for debluring images like this. It supports a wide array of blur algorithms. I've used it to reverse passwords and identifying details released by security researchers.

I was unable to retrieve anything of value from the blurred areas of this image.

[1] http://smartdeblur.net/


if you think someting is unsafe why would try to call more attention to it?


So it can be fixed? The chance that evildoers have not already noticed this is pretty slim.


Ah, secrecy through obscurity XD


To prevent it from happening again!


See the contact info here:

https://ssu.gov.ua/en

If this is a real threat, you should contact them directly and delete this post. Why would you post it publicly?


This site can be read by people who support the aggressor. I know it is more work, but just in case there are some some less open channels that could be used instead (for example, emailing or calling trusted Ukrainian representatives/embassies, just as long as you don't occupy the life and death helplines).


It does not matter - the serious actors are already on it anyway.


Or maybe it is a trap? expecting the Russians to un blur it and see the secret plans which are actually a trap for their forces. It's not unheard of.




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