Generate Secret Shares

Before you begin, prepare the following:

  1. The secret to be shared. Sunder accepts text or file input.
  2. The size of the group. This can be any number greater than 1.
  3. The size of the quorum. This can be any number between 2 and the size of the group.

Open Sunder. The first thing you will see is the home screen, with two buttons: Sunder It and Recover It.


To generate secret shares, click Sunder It.


There are two sections on the Create Secret Shards page: Enter Your Secret and Share Options.

If you wish to enter your secret as text, leave the Enter Your Secret dropdown menu set to As Text and type or paste your secret into the text box. You may choose to toggle the Hide secret? checkbox to hide the secret text.

If you wish to enter your secret as a file, click the dropdown menu and select From File. Click the Select File button to open a file picker. You may choose any file up to 1MB in size for your secret.

In Share Options, enter the size of the quorum in Shares needed to recover the secret and the size of the group in Total number of shares. Sunder validates the group and quorum parameters as you type them and will warn you if they’re invalid.


Once the form is filled and all of the values are valid, the Create Secret Shares button will be enabled. Click Create Secret Shares.


On the Distribute Secret Shards page, you are presented with a list of the generated secret shares. You can export each secret share by clicking Copy to copy it to the clipboard or Save to save it to a file. You should export each secret share and securely distribute it to the designated share holder.

Once you’re done distributing the shares, you may either click < Home to return to the home screen and continue using Sunder, or use the menu to quit Sunder.