[Archive] How to Use a Passkey as One of the Shares in MPC

Embedded Wallets (Web3Auth)
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:classical_building: Archived Content from Web3Auth Community

This topic was originally posted by date0101 on 1/13/2025.
This content has been migrated from our previous community forum to preserve valuable discussions.

Hello,

Could you please explain how to use a passkey as one of the shares in MPC Core Kit or tKey?
I saw in the documentation that a passkey can be used as MFA, but I couldn’t figure out how to implement it.
Here is the link to the relevant documentation: MFA Flows.

I’d like to use a passkey as a share to enhance security, but I’m unsure how to proceed. If you have any examples or further details on the implementation process, I’d greatly appreciate your guidance.

Thank you in advance for your help!

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Hi @date0101,

We don’t have a direct way to use the Web3Auth Passkeys server as a secondary share for MPC Core Kit right now. However, you can follow a similar approach to how we set up a social share in our quick start guide: Integration Builder | Web3Auth

Here’s what you’ll need to do:

  1. Set up your own passkey server
  2. Generate an id token after successful authentication
  3. Pass the id token to a temporary MPC Core Kit instance
  4. Get the postbox key from it to use as a factor key
  5. Use the factor key to generate a new factor