> ## Documentation Index
> Fetch the complete documentation index at: https://manuals.cobo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Back up key shares

> Learn how to back up key shares created with mobile signers and server signers to ensure data security.

After you’ve created one or many of the [3 types of private keys](/en/portal/mpc-wallets/ocw/holder-group-overview), it is a good idea to have key share holders back up their keys. Key share holders back up their key shares differently depending on whether the key shares were generated using a mobile signer or a server signer.

## Mobile signer

Key share holders can use the Portal Mobile app they used to confirm the key creation process to back up any key shares created on their Portal Mobile. See [Generate and back up your key shares](/en/guard/generate-and-back-up-key-shares).

## Server signer

Key share holders can back up their key shares using the server signer. For details, see [Back up your key share](https://www.cobo.com/developers/v2/guides/mpc-wallets/server-co-signer/key-shares-backup).