Shamir's Secret Sharing
Split a secret into shares; recover with any K.
Runs entirely in your browser — nothing you enter is uploaded, logged, or tracked.
Shamir’s Secret Sharing splits a secret into several “shares” so that any threshold number of them reconstructs it — but fewer reveal nothing. Use it to back up a seed phrase or master password across people or places without any single share being enough. Splitting and combining run entirely on your device.
Frequently asked questions
How does it work?
Your secret’s bytes define points on random polynomials over GF(256); each share is the polynomials evaluated at a different x. Any K shares interpolate back to the secret; fewer give no information.
Is it compatible with other tools?
It uses the common byte-wise GF(256) scheme. Each share is a hex string prefixed with its x-coordinate.
Is my secret uploaded?
No — both split and combine happen entirely in your browser.
What should I pick for N and K?
Choose N total shares and a threshold K (≤ N). For example 3-of-5 tolerates losing two shares while needing any three to recover.