QRToken

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  Chose a coin / token

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  Token approve

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  Generate QRToken Cards

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  Download a card as PDF

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  Print an QRToken

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  Spread the cards

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  Scan the QR Code

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  Redeem the tokens

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  Enjoy the crypto

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  QR-MerkleTree

Inspiration

We desired to create decentralized QR-Code based AirDrops on real-life events with O(1) upfront transactions.

What it does

Allows anyone to print and gift QR-Codes with tokens locked inside each.

How we built it

We create angular-based dApp with Solidity smart contracts and proposed EIP-1837.

Challenges I ran into

Specially invented MerkleTree of addresses with truncated 160-bits hashes to protect from front-running attack and reduce QR-code size. See presentation slides.

Accomplishments that I'm proud of

First in the world decentralized QR-code AirDrops First EIP about redesigning Ethereum fees, which can work today for any miners

What I learned

Had 2 nights full of debugging Merkle trees and verifying signatures related issues :)

What's next for QRToken

Going to propose ETHGlobal sponsors to use this Dapp for upcoming hackathons and different real-world events.

Built With

• 0x
• aave
• binance
• blockchain
• chainlink
• ethereum
• kyber
• smart-contract
• solidity