Horcrux is a CLI utility that will take a file and use Shamir's Secret Sharing Scheme to break it into multiple files. It is still a work in progress, and has some problems still, so use at your own risk.
Currently, Horcrux only works for text files. This is planned to be updated before v1.0
To split a file, after building, run ./horcrux -s [filename] [minimum shares] [total shares]
Example:
./horcrux -s test.txt 3 5
The above will splt the file test.txt into 5 total shares, requiring at least 3 of them to recover the information. The share files will be called share1, share2, etc.
To recover a file, after building, run ./horcrux -r [filename] [share_file] [share_file]... (list all share files after filename)
Example:
./horcrux -r output.txt share1 share3 share5
The above will recover the secret file into output.txt from the share files listed after output.txt. If not enough shares are present, the file will not be created.
NOTE: when splitting a file, a file named header.txt is created. This file is required in order to recover the secret. An issue as been opened to no longer require this file, but for now it is required. Sorry.
For those wondering where the name came from, Horcrux is an item from the Harry Potter series of books (spoliers in the link): https://en.wikipedia.org/wiki/Magical_objects_in_Harry_Potter#Horcruxes