An alternative for repairing STOP Djvu encrypted photos

By | July 28, 2020

Over the past few months I did a number of videos that show how you can use JPEG-Repair (the repair part of the JPEG-Repair Toolkit) to repair STOP Djvu encrypted photos. During the making of the videos and also while investigating photos for customers I found that most photos can be repaired. This includes JPEG type photos but also various RAW photo format such as Canon RAW (CR2), Nikon RAW (NEF), Sony RAW (ARW – Only embeds smaller JPEG previews!) etc..

Repairing STOP Ransomware encrypted photos often is a lot of work

While grabbing full resolution JPEGs fro Nikon RAW (NEF) is relatively easy and straight forward, repairing the JPEG inside a CR2 involves quite a bit of work as the JPEG itself is partially encrypted too. If the photo is a JPEG then part of the file is encrypted by definition and this also means more work and implies the requirement of a reference file.

So while repair using JPEG-Repair is possible and a relatively low cost solution, it requires a lot of time and effort (just watch some of the videos to see what I mean). This week I was helping a data recovery lab repair CR2 files affected by the STOP ransomware. An engineer repairing individual photos, file by file, while spending several minutes on each file becomes a costly endeavor.

For an end user it may be plausible to invest more time than money. From a data recovery lab’s point of view time is money. Each minute and engineer spends on repairing photos will be charged. Repair of a few dozen photos may become more costly than recovering hundreds of photos from a corrupt memory card.

The alternative: jpeg-repair.org

To help find my customer find a more economical viable solution I fed some of his STOP Djvu affected files + matching reference file to the online web based automatic repair service jpeg-repair.org. You can trial the service for free, however repaired photos are heavily watermarked.

jpeg-repair.org, web based, automated photo repair service

The process is easy enough: drag and drop the damaged photo to the appropriate box, and also do so with the reference file. Just like with JPEG-repair you need a reference file shot with the same camera and settings (specially resolution is important).

For testing purposes I fed it RAW files for ‘to be repaired files’ and a JPEG as reference (that I extracted from intact RAW file), but I also tried feeding an intact RAW file as reference. In both cases I got decent results! So the tool is intelligent enough to find the embedded JPEG within the intact RAW file and use it as a reference. Because, just like with JPEG-Repair (my tool), the end product is a JPEG file! The online service can not actually repair RAW photos.

Prices range from 19.99 – 99.95 (Euros). For 19.99 you can repair 10 photos. To repair upto 250 photos you pay 49.99 and to repair up to 1000 photos you pay 99.99. More pricing is available for those who want to ‘resell’.

So for my data recovery lab friend, jpeg-repair.org may actually be a good option. For a reasonable price he can offer to repair upto 1000 photos for his client without having to dedicate and engineer for days worth of time to the job.

You as a home user may even consider you rather spend time than money, in which case JPEG-Repair is the best option if you need to repair more than, say 10 files.

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