Restoring Shared Secrets Like Passwords

[Main Page]

What the heck! This page needs JavaScript, and it seems that JavaScript is not enabled. Maybe you want to use a different browser?

Oh bother! The hashing functionality of this page (used for verification of the restored secret) uses 'crypto.subtle' which is only available in a so-called secure context. It seems that your browser thinks the context of this page is not secure. Maybe you can use a different browser or load this page from a different context? Otherwise, you can't verify the secret - restoring the secret itself is not affectd.

Hey there! Are you here because you have a number of so-called shares for a secret like a password and you want to re-create the secret from them? If yes, and if the shares were created with this (compact notation) or this (JSON notation) tool, then you are in the right place.

So you have shares data in compact or JSON notation. Put them in the input fields below, replacing the example shares data there:

Secret or password restored from the above shares:

Validation of secret through shared hash: Not validated

Share identifiers match: Not validated

Restore status: OK

For detailed technical information on what is going on here, create any shares on the share-creation pages (see above) and read the information provided with them. If you are a nerd, here is the summary information: Shamir's Secret Sharing, GF256 with polynomial 0x11b, UTF-8, lower-endian bytes, first byte of share is the share's x value, secret possibly padded with trailing zeros, share verification SHA-256 hash of unpadded secret, random identifier.

Also, maybe you'd like to see the source code of these pages on GitHub or download the full distribution package of these pages which can simply be unzipped and opened in a browser. It also contains the project's sources (mainly Typescript & HTML).