Integrate Two-Factor Authentication (2FA) for smart contracts using Chainlink oracles

Name of Project / Company

2FA for Smart Contracts using Chainlink oracles / Digital Bridge

Application type


Proposal overview

We propose integrate a Two-Factor Authentication (2FA) Oracle system helping developers of Harmony community to build and offer a key component easy to implement to bring a standardized security layer to the users of their DApps. This feature will have a great impact in the massive adoption.

This is the base to add, in the future releases and other authentication factors.

It will be designed to help developers solve 2FA problems by implementing its service with the best features set.

The full proposal can be viewed in a google doc here: Harmony Grant Proposal - Google Docs

Benefits for developers

Simple to Implement
We will provide a 2FA validation platform for any application — with the flexibility to fit your needs.

Implement 2FA in few minutes
With a few lines of code you can have 2FA for smart contracts integrated in any dapp. We provide SDK & Quickstarts to help you succeed on your implementation

DAOs, DeFi protocols, Games and General purposes smart contracts use cases:

  • Confirm high-value trades, transactions or withdraws
  • Confirm changes to sensitivity settings
  • Temporarily delegate a set of tasks to a third party
  • Reconfirmations of security authorization within Apps that employ time-based lockouts
  • As a step of some key, account or funds recovery method.


Digital Bridge IO
Startup working in the trusted bridge between web2 and web3, working with protocols helping them in the development of middleware in Blockchain Ecosystem.

Alejandro Pronotti
Systems Engineer - Co-Founder and Lead Developer - Chainlink Developer Expert

Mateo Hepp
Electronic Engineer - Co-Founder and Lead of Infrastructure Service and Security

Javier Salomón
Co-Founder Community Lead and Growth - Chainlink Community Advocate

Proposal ask



  • 5K At the beginning to get the initial resources to design, test and adjust the main technology involved in the proposal.
  • 5K The generated users for testers are already stored in a smartcontract as storage to be consumed by the Chainlink node adapter.
  • 10K The Chainlink node adapter is developed and passes the tests.
  • 10K Deployment of the Chainlink node with the development environment ready.
  • 10K The system, which replaces the 2FA provider (validator), is able to receive a preset timestamp, the encrypted secret key and hashed PIN as input and returns the expected result from Oracle.
  • 10K SDKs and Quickstarts documentation are ready.
  • 10K End of the project where the platform is ready for any developer that needs to test the integration of 2FA in their DApp.

Metrics for success

100% Unit tests passed ok, for the platform. SDKs and Quickstarts documentation are ready.


12-16 weeks

External links

Digital Bridge article about “How to Connect a Two-Factor Authentication (2FA) API to a Smart Contract With Chainlink” in the Chainlink blog:

Judges’s Pick Award in the 2020 Unitize Hackathon: Showcasing the Winners of the 2020 Unitize Virtual Hackathon

Chainlink Integration Announcement:

Automatically fill in verification codes on iPhone: Automatically fill in verification codes on iPhone - Apple Support

Community Feedback

Stephen Tse, CEO of Harmony

Captura de Pantalla 2021-11-09 a la(s) 15.58.28


Digital Bridge


This is a wonderful project. I doubt anyone from the community would disagree. I hope it gets approved.

1 Like

Closing this proposal for now since it is out of scope. To be revisited later.