TwoChain: Leveraging Blockchain and Smart Contract for Two Factor Authentication

User identity and personal information remain to be hot targets for attackers. From recent surveys, we can categorize that 65.5% of all cyberattacks in 2018 target user information. Sadly, most of the time, the system's security depends on how secure it is the implementation from the provider-side. One defense technique that the user can take part in is applying a two-factor authentication (2FA) system for their account. However, we observe that state-of-the-art 2FAs have several weaknesses and limitations. In this paper, we propose TwoChain, a blockchain-based 2FA system for web services to overcome those issues. Our implementation facilitates an alternative 2FA system that is more secure, disposable, and decentralized. Finally, we release TwoChain for public use.