sss-cli

Shamir Secret Sharing Command Line Interface

A simple command line interface for generation and recovery of a shared secret.

Usage

This tool has 2 main functions:

• Generation of Shares of a secret
• Recovery of a secret, using those shares

Generating a Secret and Shares

To generate shares, run the following command:

./sss-cli generate minNumShares numShares

minNumShares is the minmum number of shares required to recover the secret

numShares is the total number of shares generated

minNumShares must never be greater than the total number of shares

After running this command, the output will be printed to the console and will look like this:

>./sss-cli generate 4 8
FIELD MODULUS = fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f
Generating  8 shares with threshold 4  for recovery:
Secret :  5b89a30d37b59e9a849c7f114d0215e415db6d082703898e0813ec4c9bdd9a3
Shares :
1        16741fc130afe8e324135418f1bbb88137676baa635c4ae5da583489077256f3
2        fa6717b6f1ee01bc4e94da1a6363c5ca9c47228b4acdc6d270551335a855a484
3        573cfe4082b489aa9224bec5c450a1d38c3dbd6fae5c7bc3c9c559e35f7e4919
4        d2a14f8c4e8265e3591966eb6f0aa535238c1e5403a0391f0df687a5e002b860
5        123f87c8c0d67b9c0dc9375bbe1a28887e732734c030ce4964361b95dcf9791c
6        bbc32324452fb00a1a8a94e70c078466b933ba0e59a60aa7f3d194c70978fefb
7        74d79dcd470ce862e9b3e45db35b1168f00eb8dd4597bd9fe41672521897d0c0
8        e32873f231ed09dbe59b8a900e9d28283f45059df99db6965c52334bbd6c65ea

Also, a folder named shares will be generated in the same folder as the executable. It will contain text files named by numbers. Each file corresponds to a single share which a user would distribute amongst individuals sharing this secret

the-top-folder
    sss-cli
    shares
        1
        2
        3
        4
        5
        ...

Recovering a Secret

To recover a secret, first create a folder named shares in the same directory as the executable so your directory looks like this:

the-top-folder
    sss-cli
    shares
        1
        2
        3
        4
        5
        ...

Put share files in the shares folder like in the example above.

Now run the following command:

./sss-cli recover

The output should look like this:

Secret successfully recovered from 8 shares: 5b89a30d37b59e9a849c7f114d0215e415db6d082703898e0813ec4c9bdd9a3

Help

The following is the help text for the cli

NAME:
   Generation of Shares and Recovery of Secrets - Shamir Secret Sharing - Generate Shares and Recover Secrets using a threshold of those shares

USAGE:
   sss-cli [global options] command [command options] [arguments...]

VERSION:
   0.0.0

COMMANDS:
     generate, g, gen  generate [minNumShares] [numShares] - generates numShares shares of a secret which can only be recovered by numMinShares shares
     recover, c        recover [pathToSharesFolder] - recovers a secret given a path to a folder with the generated shares
     help, h           Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h     show help
   --version, -v  print the version