paper-secret/README.md

Paper-Secret

Shamir Secret Sharing on paper using gfshare.

Installation

gfshare is required to split and merge the secret. See man gfshare for an explanation of Shamir Secret Sharing in gf(2**8).

sudo pacman -S --needed libgfshare

qrencode and imagemagick (convert) are required to create and merge QR-codes during the split process. One can set the according parameters of split_encode to False to skip this step.

sudo pacman -S --needed qrencode imagemagick

enscript is required to create a PDF containing the split secret in text form. One can set the according parameters of split_encode to False to skip this step.

sudo pacman -S --needed enscript

Usage

Create a secret:

cat > secret.txt

Split the secret into 5 lines:

./enpaper.py secret.txt

Manually delete up to 2 of the 5 lines in secret.txt_txt.txt.

Then recreate the secret:

./depaper.py secret.txt.split-text.txt

Print the secret:

cat secret.txt.split-text.txt.merged.txt

Notes

• https://en.wikipedia.org/Shamir's_Secret_Sharing