Question (.7z, .zip) Broken? password-encrypted archive files

Jul 20, 2020
Around January or February, I had some files (mostly images and videos) to store that mean a lot to me, but that I didn't want anyone else to see under any circumstances.

So I used a really old (and small in capacity) USB stick of mine, wiped it completely clean with 30+ overwrites, and created the 478 MB NTFS partition on it (the entire USB stick).

I put my files into a password-encrypted .7z file (more on the passwords below), which I then put into a .zip file encrypted with another password, which I put on the stick, which I encrypted with BitLocker. The last time that I picked up the USB stick before writing this post, I removed the BitLocker protection.

I assigned the file names of the archives in a way that would make only me remember them. For example, if the password was InterstellarCNolan2014 , I would name the file .

Before I get into my problem, here's the structure of the USB stick, just to make things clear:

USB stick --> Encrypted .zip file --> Encrypted .7z file --> My data

I use 7-Zip to extract my data from the .zip file because Windows Explorer can't. I enter my password, it extracts the .7z file (whose name I can see, I didn't encrypt the folder structure), everything seems fine, until it's at 100%, and 7-Zip gives me the following error message: "CRC failed: Wrong password? : IxxLxxxxxNN.7z". So you would think that I entered the wrong password, right? But I know for certain that I didn't, because entering literally anything else as the password gives me the similar error message ("Wrong password : IxxLxxxxxNN.7z", and I get the error message at 0%, NOT 100%.

And I know that it's not asking for the password of the .7z file, because if I enter that, I get the latter error message, again at 0%.

The "exported" .7z file that I end up with is 225,445,089 bytes large (the .zip file is 225,445,263 bytes large). When I try to simply open the .7z file in 7-Zip, I get the error message "Can not open file 'C[...]\IxxLxxxxxNN.7z' as archive", and only that error message. 7-Zip doesn't even launch.

If anyone can tell me what's the problem here, and how I can get my data back, that would be of great help. I remember the files as being and extracting just fine in January and February, but I don't know for sure, so don't take my word on that.


Mar 16, 2013
It IS the only copy, but I tested it. As I said, I remember the extraction process as working just fine back then.
And flash drives fail. Far more often than just about any other current data storage device.
Especially if they are OLD, 500MB flash drives, that have been abused with "30+ overwrites ".

If your known procedures for peeling this onion has failed, there isn't a lot anyone out here can do.
Reactions: Mandark


Feb 13, 2018
hello fellow intersteller fan, you might want to try extracting again, and recovering what data you can from the partial extraction. after doing that and getting what you can, try copy the file to a local drive. if it flops partway through, you know you got a drive error. maybe run some drive checks too. if you can only get the temporary data, consider it a win and cut your losses. next time, use someting like a keepass db, stick it in the cloud somewhere, and commit to memory properly a long pw, and put a security key file on a couple floppies. thats what i do, works super well. floppy disks ftw.