Rolodex - Decentralised Blockchain Directory

It is hard to make a payment to someone in crypto.
You need to know the public address of a person to send crypto to them.
Public addresses are a long list of alphanumeric characters and its impossible to remember.
A minor error while copying or typing these public addresses could lead to funds being lost.

How about every user will have a blockchain username?

It will be great if we can have a database of usernames mapped to their respective crypto public addresses for each currency. But this database has to be reliable and not hackable. Nobody should be able to change the data into the database.

So centralised database are hackable and not reliable.
But we can use the potential of smart contracts to solve this by creating a truly decentralised mapping system of usernames to wallet addresses.

So we use smart contracts.

We need to create two smart contracts

  1. Smart Contract: UserList
  2. Smart Contract: UserData

This is kind of relational database.

Smart Contract: User List

Only one smart contract is created by us. This will have functions to add a new user and their relative smart contract address.

Anyone can add a username and a smart contract address field to it.

Smart Contract: User Data

This smart contract is created by the user themselves. Because only the user should be able to change the data in this smart contract. At the same time this smart contract will also possess the list of authorised users who can also read these data.

We can able to achieve this all using the Elastos Ethereum Sidechain System

DrifterSince89: Full stack developer & designer with more than 8 years of experience.

PoC is already ready. Front end development is in progress. Please find it at [
1st week: Complete front end development in React native for both iOS and Android.
2nd week: ELA wallet implementation with ability to send and receive funds.
3rd week: Create wallet address and store them on blockchain.
4th week: Search user on blockchain.
5th week: Friend request and accept functionalities
6th week: Friends list and detailed profile view.

Revenue: There will be percentage in the processing fees for each profile creation, wallet address modification and friend requests.


Chen Rong named ChenRong, if I named the same name with him, what will happen?

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The list of names will be in a mapping in the smart contract.
So it will be easy and efficient to check for duplicates before creating new one.

There are no name fields in this as per the design. Only username field which is supposed to be unique. So no duplicates allowed.

While developing I may think about adding fields for first and last names which can be same still it will require an unique username.

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Thank you.
Another question, how to get the address by name? How to use it in the elephant wallet?

The smart contract handles it.
Right now there will be one smart contract with all usernames mapped to their own respective smart contract.
Calling to the main smart contract we can get the username and its own smart contract and it turn its data.

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Hi guys, the 2nd Round of voting has started, please vote your favorite projects.

You will be to able recieve a red packet after you have voted, if you only recieve a very small amount of ELA, please don’t worry.
As the wallet with the smallest amount of ELA in a red packet will receive another bonus red packet, containing10ELA at the end of the voting.

Voting URL:

At the same time, you can add VoteForMe mini program to your elephant wallet via this URL