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TapTrust redefines event experiences with NFC & Ethereum's Account Abstraction, offering a unique, etherless way to engage. Each tap with your NFC chip signs transactions & maintains privacy with a fresh, anonymous address.


Created At

ETHGlobal Istanbul

Winner of


Arx - Best HaLo Use 3rd Place


Base - Best use of Account Abstraction and Base Paymaster 2nd Place


ETHGlobal - 🏆 ETHGlobal Istanbul 2023 Finalist

Project Description

TapTrust revolutionizes event engagement by harnessing NFC technology with Ethereum's Account Abstraction.

Each attendee receives a fresh NFC chip with a unique keypair, enabling them to interact with Ethereum transactions, even without Ether, ensuring seamless active participation that preserves their privacy.

This innovative approach provides a new, private address for each user, maintaining anonymity while fostering transparent event interactions. TapTrust is more than just an entry tool; it's a gateway to a new era of privacy-centric, decentralized event experiences, where every tap is a secure, anonymous link to the blockchain world.

How it's Made

The implementation of TapTrust, an innovative venture at the intersection of event experiences and cutting-edge technology, is a testament to the harmonious integration of advanced technologies and strategic collaborations. Let's delve into the specifics of its implementation:

  1. NFC Chips from Arx: Central to the TapTrust experience are the NFC chips provided by Arx, a leader in secure NFC solutions. These chips, embedded with unextractable cryptographic key pairs, offer unparalleled security for transaction signing. They are the primary interface for users, combining high security with ease of use, a critical combination for smooth and secure event participation.

  2. Blockchain Platform - Base: Our blockchain of choice is Base, renowned for its focus on real-use case scenarios. Base's robust and scalable infrastructure is ideal for managing the high volume of transactions generated in dynamic event environments, offering the reliability and performance essential for TapTrust's smooth operation.

  3. Account Abstraction via Alchemy: Leveraging Alchemy's Account Abstraction infrastructure, TapTrust offers a user-friendly way to interact with the Ethereum network. This innovative approach allows attendees to sign transactions using their NFC chip without the need for Ether, significantly lowering barriers to entry and enhancing the user experience in blockchain interactions.

  4. Verified Credentials with Ethereum Attestation Service: Working alongside event organizers, TapTrust utilizes the Ethereum Attestation Service to issue verifiable credentials. These credentials are key for regulating access within the event, ensuring secure and authorized entry to designated areas. The use of blockchain for credentials not only bolsters security but also adds a layer of trust and transparency to the process.

  5. Voting Smart Contract Example: As part of our implementation, we've developed a sample Voting smart contract. Event attendees can vote on various aspects of the event through their unique Account Abstraction contracts, utilizing the NFC chips as signers for gasless transactions. This voting mechanism is just a glimpse of the potential applications; other possibilities include betting systems and minting of Proof of Attendance Protocols (POAPs), each leveraging the unique capabilities of our platform.

  6. Permissionless and Tokenless Framework: TapTrust adopts a permissionless and tokenless model, emphasizing inclusivity and accessibility. This approach allows open participation without the need for tokens or permissions, aligning with the decentralized nature of blockchain. It further reinforces privacy, as it enables users to partake in activities without linking them to a token economy or specific permissions.

In essence, TapTrust is set to revolutionize event experiences by merging the simplicity of NFC technology with the robustness of the Ethereum blockchain, supported by strong partnerships and a dedication to privacy and accessibility. This initiative is poised to make event participation more secure, private, and user-friendly, heralding a new era of decentralized, engaging, and interactive event experiences.

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