KohGeek / pysecretsharing

Simple Python Secret Sharing Program

Simple Python Secret Sharing Program

Warning

Not validated for high security use. Can be useful for simple secret sharing.

The program uses AES EAX mode to encrypt/decrypt a file and then uses Shamir's Secret Sharing to achieve secret sharing.

Setup

Install all the dependencies listed in requirements.txt.

Example

To encrypt a file, run the following command:

python3 encrypt.py <input_filename> <output_filename> <shares_filename>

To decrypt a file, run the following command:

# runs in interactive mode
python3 decrypt.py <input_filename> <output_filename> -i

or

# provide shares as command line arguments
python3 decrypt.py <input_filename> <output_filename> -s <share_1> <share_2> ... <share_n>

Help

Help for encrypt.py

usage: encrypt.py [-h] [-e e] [-v] [-n N] [-t T] input output shares

Produce an encrypted file and a set of shares.

positional arguments:
  input                 Input file name
  output                Encrypted file name, should be in .json format
  shares                Shares file name, usually in .txt format

options:
  -h, --help            show this help message and exit
  -e e, --encoding e    {hex|b32|b64} Encoding to use for shares. Default: b32
  -v, --verbose         Verbose output.

Shamir's Secret Sharing Scheme:
  -n N, --needed_shares N
                        The number of shares required to reconstruct the key. Default: 3
  -t T, --total_shares T
                        The total number of shares to produce. Default: 3

Help for decrypt.py

usage: decrypt.py [-h] [-e e] [-v] (-s S [S ...] | -i) input output

Decrypts the encrypted file with a set of shares.

positional arguments:
  input                 Encrypted file name, should be in .json format
  output                Output file name

options:
  -h, --help            show this help message and exit
  -e e, --encoding e    {hex|b32|b64} Encoding to use for shares. Default: b32
  -v, --verbose         Verbose output.

Share input:
  -s S [S ...], --shares S [S ...]
                        All shares required to reconstruct the key.
  -i, --interactive     Interactive mode. You will be prompted to enter the shares.