# Update- Glad to Share that this submission has Won in the Chainlink 2022 Fall hackathon

https://devpost.com/software/decentralized-kameti?ref_content=my-projects-tab&ref_feature=my_projects

Social Impact using Chainlink Services & Polygon ID - ROSCA's

Solidity code inside contracts

Run locally on Remix (Polygon Mumbai Testnet) with Subscription Id: 2651

Motivation

We wanted to build something in the Social Impact category. We interviewd some locals to get a better idea of pain points that "Blockchain tech, Chainlink & Polygon" can solve while being user-friendly.

What is (Decentralized) Kameti?

We came across a problem thats a very common cause of People losing their life-savings to fraudsters and lack of paperwork & trust, knows as KAMETI's in Asia or more generally ROSCA(Rotating Savings And Credit Association).

In simple words, a group of people agree to save collectively and an organizer chooses a person (in a so-called random process writing names on paper pieces and picking one from them) every month who access the whole pool for that month. So, 5 people with 100$ monthly payment means 500$ pool every month. So, everyone gets access to a big amount randomly.

There are other types of these kind's of savings that our dapp's code can support with just a little bit changing for each.

Problems:

We pin-pointed some of the most crucial problems in this process that everyone involved face

• Trust Issues (more specifically organizer favors people in the selection process) => Solved using Chainlink VRF

• Identity Issues (in case someone defaults, we don't have their right ID) => Solved using Polygon ID

• Transaction Records => Solved using IPFS storage & Polygon's native ledger (no one can manipulate or delete)

Technologies:

Using Chainlink (Eliminate Trust Issues)

=> Getting a random number from chainlink VRF to select the winner

Using PolygonID (Eliminate Identity issues)

• We can't upload People's ID directly on the chain, thanksfully Polygon ID allows us to issue zk-claims (by getting their ID details off-chain and saving cryptographically) to people that they can later use for authentication on smart contracts & our other services.

Using Polygon (Eliminate Transaction Records issue)

• Uploading all the event data & Transaction details on the Polygon Network. We get an immutable ledger that no one can manipulate or delete like physical ledgers.