Develop an ethereum smart contract for storing hashes (strings)

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.

Kemahiran: Ethereum

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Tentang Majikan:
( 7 ulasan ) argoncilhe, Portugal

ID Projek: #17041781

10 pekerja bebas membida secara purata €222 untuk pekerjaan ini


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 Lagi

€200 EUR dalam 10 hari
(9 Ulasan)

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

€188 EUR dalam 5 hari
(1 Ulasan)

Hello, I have reviewed your project description and I would like to create a smart contract for storing hashes in the blockchain with all features as per your requirements. Let me show you an Example : pragma so Lagi

€100 EUR dalam 5 hari
(0 Ulasan)

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. Lagi

€55 EUR dalam 7 hari
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Hi, My name is Atif Zahid, Founder & CEO at Maxnet Technologies ([login to view URL]). I hope this note finds you well and you having a great day. Quick favor if you could find time to go through my portfolio below. Lagi

€155 EUR dalam 3 hari
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Hi there, I would like to develop Ethereum based SMART CONTRACT and TOKEN ( ERC20 / ERC223 / ERC721/ ERC777) , We have developed many applications related to crypto-currency and BLOCKCHAIN. Please have a look at Lagi

€150 EUR dalam 4 hari
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Hi, I have a team of blockchain developers, we have expertise in Whitepaper, Smart Contract, Crowdsale, Audit report. Have gone through with the requirement and will take around a week as we need to take care of Lagi

€800 EUR dalam 8 hari
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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 Lagi

€130 EUR dalam 5 hari
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We are a group of Passionate Blockchain people who strongly believe that Blockchain (Decentralization) is the [login to view URL] do several Blockchain things to help the community. We deliver projects, poc's. We do offline and Lagi

€222 EUR dalam 3 hari
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