# Shamir Secret Sharing Toolkit

> just built an offline Shamir Secret Sharing (SSS) Seed Phrase encoding tool!!

**Published by:** [0xself](https://paragraph.com/@0xself/)
**Published on:** 2026-04-10
**Categories:** shamirsecretsharing, sss, encode, encodingtool, seedphraseencoding, shamirsecretsharingtoolkit, shamirsecretsharingtool, decode, encoding, decoding, sssencoding, github, toolkid, encodingtoolkit, githubtoolkit, jsx
**URL:** https://paragraph.com/@0xself/shamir-secret-sharing-toolkit

## Content

GitHub - balgar271/Shamir-Secret-Sharing-Seed-Phrase-Encoding-ToolContribute to balgar271/Shamir-Secret-Sharing-Seed-Phrase-Encoding-Tool development by creating an account on GitHub.https://github.comIt consists of: A general-purpose encoding/decoding tool for any text secret:Split any text into n shares with a configurable threshold kCombine k or more shares to reconstruct the originalSupports up to 255 shares (GF(256) field limit)Hex-encoded shares with one-click copy The SSS BIP-39 Seed Phrase Encoding Toola purpose-built tool for protecting BIP-39 cryptocurrency wallet seed phrases.BIP-39 validation: checks word count (12/15/18/21/24) and formatoffline: live network status banner warns if you’re onlinemasked input: seed phrase hidden by default with show/hide togglea step-by-step flow: enter → configure → generateDownload shares: export all shares as a .txt fileViewport toggle: switch between mobile and desktop layouts to preview responsiveness -> Uses crypto.getRandomValues() for cryptographically secure randomnessHow it works: Shamir’s Secret Sharing splits a secret into n pieces such that any k pieces can reconstruct it, but k − 1 or fewer reveal absolutely nothing about the original. The scheme works by:Treating each byte of the secret as a constant term of a random polynomial of degree k − 1Evaluating that polynomial at n distinct points over the finite field GF(256)Each evaluation point becomes a shareReconstruction uses Lagrange interpolation at x = 0 to recover the constant term All arithmetic is performed in GF(2⁸) using the irreducible polynomial x⁸ + x⁴ + x³ + x + 1 (0x11b), which ensures every non-zero element has a multiplicative inverse.

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