pawpyrus 2024.3.24.0

A minimalist paper data storage based on QR codes

Description

Pawpyrus is a minimalist open-source paper data storage based on QR codes and ArUco. It generates a PDF from any small-sized binary file (recommended size <100kb). Further, the paper data storage can be scanned and decoded (recommended resolution 300dpi).

It can be useful if you need to backup data on paper:

• Encryption keys (e.g. GnuPG)
• File-based password databases (e.g. KeePassXC)
• Cryptocurrency wallets

Usage

NOTE: Backward compatibility is not provided yet.

Encoder:

pawpyrus Encode -n "Description" -i  "input.file" -o "output.pdf"

Also, pawpyrus can read data from stdin. For example, encoding GPG public keys:

gpg --export 0xDEADBEEF | pawpyrus Encode -n "My pubkey" -i - -o "my-pubkey.pdf"

Decoder:

pawpyrus Decode -i "scan1.jpg" "scan2.png" "scan3.jpg" "masked/too/*.png" -o "output.file"

Data Format

Pawpyrus uses a custom alphanumeric encoding, which is designed to store information in QR code effectively. For now, that makes 4.3kb per A4 page (pixel size 0.6 mm).

Got a Trouble?

QR and ArUco detectors may fail on one or several blocks. The situation is totally normal, although uncomfortable. I fixed it for now, with two detectors (opencv and pyzbar) instead of one, but the bug may reappear in some circumstances. That's why I implemented Debug Mode:

pawpyrus Decode -d "debug_dir" -i "scan1.jpg" "scan2.jpg" "scan3.jpg" -o  "output.file"

With Debug Mode, you can inspect undetected QR codes, read them manually with any device you have, and create a file with text blocks which can be processed as well:

pawpyrus Decode "scan1.jpg" "scan2.jpg" "scan3.jpg" -t "unrecognized_codes.txt" -o "output.file"

Similar Projects

1. intra2net/paperbackup
2. Paperback by Olly and Wikinaut/paperback-cli
3. colorsafe/colorsafe
4. Twibright Optar
5. Paperkey
6. 4bitfocus/asc-key-to-qr-code