Ujjo - NFC wallet cards

Project Name: Ujjo
Project Track: Web3
Team Name: Why not?
Team Member(s): 1
Dorahacks Project Link: Ujjo | Buidls | DoraHacks
Project Goal:
The project has multiple goals:

  • Сreating an application for saving an account (wallet) on an NFC card. It is a cheaper alternative to Ledger and more reliable than writing on paper.
  • Creation of infrastructure for the popularization of the TRON cryptocurrency (Including among those who have not previously used cryptocurrency). NFC cards can be used as gift cards or as an alternative to selling crypto through exchanges.

Source code: GitHub - tanya1997/ujjo
Project Info: Ujjo is a web application that allows you to create wallets and write them to NFC cards, as well as read information from previously written cards.

Main features of the application:

  • Creating a new wallet and writing various tokens to it (TRC-20, TRX, TRC-721)
  • Wallet export via private key
  • Real-time wallet balance display
  • Possibility to protect the wallet with a password when writing using the AES encryption algorithm
  • Write and read wallet to NFC card
  • Verification of the integrity of the private key when reading with crc
  • The ability to send tokens to other wallets after reading the NFC card

Project Website: https://ujjo.netlify.app/
Project Test Instructions:
For testing, you will need an nft-enabled smartphone (on Android) and an NFC card 13.56 mhz (example)

Instructions for creating an NFC card:

  1. open website https://ujjo.netlify.app/
  2. click on the button “create card”
  3. create a wallet
  4. transfer test tokens (trx) to it on the nile or shasta chain
  5. set a password for the wallet (optional)
  6. write the wallet to the card by bringing the card to the smartphone

Instructions for reading NFC cards:

  1. open website https://ujjo.netlify.app/
  2. click on the button “scan card”
  3. bring the NFC card to the smartphone to read
  4. enter password (if required)
  5. after opening the wallet, you can see the balance and transfer tokens to another wallet

Project Details:

The application is a web application that allows you to read and create NFC cards. It works in the browser and does not require installation (Only for Android devices: smartphones, tablets or terminals).

                         Data written to NFC card (json):
/*private key encrypted or not (user selects)*/
   "crc":"9922b268", //crc for the key (the private key is always checked in decrypted form).
 /*If the key is encrypted, then when the user enters the password, the correspondence between 
    the decrypted crc key and the given crc is checked. 
    Encryption method: AES.*/
   "secure":"true", //flag indicating whether the private key is encrypted or not
   "contracts":[ //list of tokens that will be shown in the wallet
                            Application screenshots:

                                 Create card:

                                 Scan card:

Screenshots of the previous version

                         This is an example of NFC card design:

                               Demo video:
Previous videos:

This is a mini demo video (good quality video will come later):

Smart Contract links: The application does not use smart contracts
Project Milestones:
:white_check_mark: - The opportunity to create a new wallet
:white_check_mark: - The opportunity to record a wallet on an NFC card
:white_check_mark: - The opportunity to read the wallet from the NFC card
:white_check_mark: - The opportunity to protect the wallet with a password
:white_check_mark: - The opportunity to work in different chains (mainnet, shasta, nile)
:white_check_mark: - Checking the integrity of the card when reading (using crc)
:white_check_mark: - The opportunity to view and save the private key when creating and reading a card
:white_check_mark: - The opportunity to work with various tokens (usdd, custom tokens) and NFT


Team name: why not? Meaning
Undoxxed right?


By the way welcome to HackaTRON S4.
Great initiative. Would love to learn more about this. Waiting patiently for website and other materials to learn more :pray:t2:
All the best


Not alot is being given out here, anticipating upcoming updates, welcome to Season 4.



welcome to session 4 HACKATHON
All the best.

Not enough material yet.
But quick question.

What the security measures for the NFC wallet?


Bienvenido al S4, me gustaría saber las ventajas frente a las otras opciones existentes en el mercado de su tarjeta. Gracias


Welcome to join onboard in this year’s S4 of the Tron hackathon. Excellent initiative you’ve got with your project. I’d love to find out more information on this. eagerly awaiting for your website and whitepaper to read more about your project.

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Hoping to learn alot from this project …
seen alot of this but the use-cases aren’t great

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Good evening. The private key will be stored in encrypted form on the NFC card. To access the wallet, the user will have to enter a password.
The password is set when the wallet is created (optional).

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Do you get seedphrase when creating nfc card?

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Thanks for clarification

All the best to your project


Welcome to hackathon4, your project is interesting as another alternative option.


I like your project because it works on any device, it doesn’t need any special app . With any web browser you’re good to go
Congratulations in advance…


Welcome team, just want to clear some doubts, the NFC card will serve like an ATM card linked to your wallet address and a person can person transactions with the card without necessary having to open the wallet in the first place.

Please correct me if i am wrong


Hello. No. The card serves as the key to the wallet. The private key is stored on the card in encrypted form.
However, it is possible to develop software for the ATM terminal. Not in this hackathon.

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TronWeb api is used to create a wallet. At the time of creating the wallet, you can view the seedphrase. However, the seedphrase is not saved in the app or anywhere other than the NFC card.

The application code will be fully open source by the end of the hackathon.


Oh great, okay
Thanks for the clarification.
All the best

Oh ok, i was proposing something like this but my idea was flawed in many ways, cant wait to see how u go about yours.

Mine was to mint the seed phrase as NFT but i have found out its not good enough as the NFT will be public and therefore vulnerable.

I want to see how you approach works

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We never can tell
Idea on idea can turn out to build a perfect project.


How do you address regulatory compliance, such as KYC and AML requirements, for users of the NFC wallet cards?

1 Like