A proof of concept showing steganographic file storage. Here's an (abstract) use case:
Imagine you'd like to set up a file sharing service and have no resources to monitor its usage nor want to violate other people's privacy. Ideally, a system should let anyone write to the service and share the results, but only people who have the metadata file (in this case: a .torrent file) can access it. You'd also prefer not to leak the information about how much data there is.
This PoC attempts to solve this in the following way:
- Fill the hard drive with pseudo-random data,
- Split the file into hashed chunks like BitTorrent does
- For each chunk, calculate its offset on the drive based on the hash contents,
- Store the chunk, AES-encrypted (CTR mode) under that offset