diffseek

A tool for verifying and correcting manually transcribed strings across two devices using binary search.

Use Cases

• Airgapped systems
• Low-privilege systems without email/clipboard access
• Any scenario requiring manual string transcription between devices (e.g., copying login links, tokens, or keys)

How It Works

1. Run diffseek on both devices
2. Enter the reference string on device 1 (input is interactive to avoid shell history)
3. Enter your transcription on device 2
4. Compare hash-derived values (phrases, colors) displayed on each device
5. Binary search narrows down differences:
   • Matching hashes indicate error-free regions
   • Non-matching hashes indicate regions containing at least one error
   • At each step, the string is reprinted with color coding: orange (possibly mismatched), red (definitely mismatched), white (verified correct)

The tool uses breadth-first search when both strings have matching target lengths (to find all differences efficiently), and depth-first search when lengths differ (to find the first difference quickly).

Usage

pip install diffseek

Then,

diffseek
# or
./diffseek.py
# or
python3 diffseek.py

Disclosure

This tool was implemented by Claude Code from a specification I provided. I fixed minor bugs and verified it works for my use case. It is primarily AI-written code. You might not care, but if you do then now you know.

If you run into any problems, feel free to open an issue or a PR; these will be human-reviewed.