How to randomly pad files before encryption to prevent file fingerprinting?
Hi, I was planning to encrypt my files with GPG for safety before uploading them to the cloud. However, from what I understand GPG doesn’t pad files/do much to prevent file fingerprinting. I was looking around for a way to reliably pad files and encrypt metadata for them but couldn’t find anything. Haven’t found any recommendations on the privacyguides website either. Any help would be appreciated!
Any encryption worth being called that randomises itself such that the same file, encrypted twice with the same key, produces completely different ecrypted versions.
To put it another way, if similarities in files could be detected despite their encryption, then the encryption would be worthless.
Sounds like you want a proper backup solution. Take a look at borg backup, a tool that supports encrypted, deduplicated, compressed, incremental backups. You can even directly save to your cloud via protocols such as ssh, s3, etc.
Is there no way to encrypt the metadata of files using GPG? And how do people pad their files to prevent fingerprinting? Surely I’m not the first person to be asking about this? I haven’t had much luck searching online
GPG/PGP turns takes the file and turns it into random bits that only someone with the private key can unrandomize. There is no file metadata left. There is no nothing left. I believe the sizes are even consistent (0-1024kB files will be the same output size.)
Yes GPG should add appropriate padding (random initialization vector) to not reveal whether two ciphertexts have the same plaintext. It makes no real attempt to conceal that the two plaintexts have the same length. If you want that, best bet is to make all ciphertexts the same length, by padding plaintexts out to 1MB or whatever, and turning off compression. Actually you might first check the manual to see if there is already an option for that. There are a lot, and I no longer keep track.
Cryptographer’s saying (Silvio Micali, I think): “A good disguise does not reveal the person’s height”. So you are on the right track.
I also have media and other binary blobs which I’d like to archive in an encrypted fashion, will GPG suffice? ChatGPT mentioned OpenSSL for this but I’m not sure where that’s taking me.
Openssl really isn’t the right thing for that. GPG is fine for individual files if you don’t mind leaking the approximate length. You may be better off with borg backup depending on your exact use case.
I’m using rclone, do you recommend I run borg on top of it to encrypt said files? And does borg explicitly do what I’m trying to achieve? I’m going to take a look at the documentation, thanks
I’m not really familiar with rclone. I just use Borg and it does about everything I could want. You can even ssh mount a Borg repo as a file system and browse the files, though it is read only (you can’t modify anything that way). Obvs you need the decryption key to do that.
I will check into rclone again. People keep mentioning it. I think I may have considered it before deciding on borg. But my use case is primarily backup rather than archiving. The two aren’t quite the same.
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