Develop an ethereum smart contract for storing hashes (strings)

Closed Posted 5 years ago Paid on delivery
Closed Paid on delivery

The goal of this project is to create a smart contract for storing hashes(strings) in the blockchain and rewarding tokens for each submission. Hashes and hash infos

are to be publicly accessed without execution of functions on the smart contract (use mappings).

The reward system is based on voting and the tokens are created once each hash reaches a minimum amount of positive feedback.

The project is for educational purposes but it should be built with safety concerns as if it were a final product. (with safe adds, etc...)

The smart contract needs to be upgradeable by the contract creator to a newer version if necessary.

The functions to develop are as follows:

addHash(string hash, string name)

addReview(string hash,string comment, bool feedback)

deleteHash(string hash)

any user, except the hash's submitter, can review a hash, giving it a positive or negative (like or dislike) and providing a comment.

Once a hash is at 5 positive comments, a token is created and sent to the hash submiter. (one token, one time only per hash. if a hash reaches 5, the owener receives a

token, but if it goes to 4 and then to 5 again it wo'n be issued a new token again).

any user can add hashes to the smart contract.

Every hash is unique

Hash's owner can't provide feedback for itself.

Each user can only provide feedback one time for each hash

anyone can delete a hash(even if he isn't the owner) by spending 10 tokens and the tokens are burnt from existence.

other standard functions such as transfer tokens and create tokens(only the contract creator can create new tokens) need also to be implemented.

Ethereum

Project ID: #17041781

About the project

10 proposals Remote project Active 5 years ago

10 freelancers are bidding on average €222 for this job

manuelleal

Hello, i'm a solidity and dapp developer. Your contract seems to be very interesting, i would like to work in this project. There is only one thing, do you want only one contract that manages tokens and your "hash More

€200 EUR in 10 days
(9 Reviews)
4.0
codeman01

Did similar work before, need discussion Here is an example of erc20 smart contract 0x58646fF346611466781148b4C5F6fba610d98b66 We can talk more over chat

€188 EUR in 5 days
(1 Review)
1.7
khanzakir

I am into open source web development for more than 10 years and have been exploring blochchain lately. I have done some ethereum + solidity POC’s of my own as learning and would like to take this up at very low rate. More

€55 EUR in 7 days
(0 Reviews)
0.0
Hatekh

Hi, I have worked on building decentralised web applications before using Ethereum particularly while experimenting with the idea of an Ethereum backed version of Kickstarter. I have also implemented tokens using More

€130 EUR in 5 days
(0 Reviews)
0.0