chainlink hackathon 2020Veriphone - Creating the largest chainlink-backed archive of phone numbers.

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chainlink hackathon 2020 XRP Euro BitStamp XRP EUR... Veriphone - Creating the largest chainlink-backed archive of phone numbers.
in recent years it seemed like fake phone calls have gone up almost tenfold uh now marketers and sales people have huge incentives for getting and checking valid phone numbers to close deals but it also can seem that the amount of spam calls have reached an all-time high now robocalls can originate from like telephony services like twilio bandwidth and this has been incredibly convenient but it also has enabled a whole new breed of phone numbers and people that essentially spam to be able to come onto the market so to solve this i created an app called verifone i think before we had yellow books which for those of you that are old enough you would essentially have a catalog of every single phone number where i linked to but i wanted to be able to leverage both the ability to index with the graph and chain link to make api calls to be able to connect and create the worlds first index or the worlds first chain link index of phone numbers to be able to do automatic lookups and see on the blockchain uh or have it preserved on the blockchain whether or not phone numbers are valid and where they originated so i created a simple contract called phone validator which is deployed on the test net and the way this works is theres a particular method called request validate validation of a phone number um and so this is a fake phone number and you can see here what it does is essentially stores the last phone and the last valid state of whatever ran on the smart contract but i can actually do a submission and go ahead and confirm that and whats going to happen is the transaction is going to be registered and it does take a few minutes so the phone number is updated and for every uh particular phone number thats passed through this contract its going to emit an event that gets indexed by the graph so lets take a look at last valid just like that it did transition to true so every single time someone calls this contract it will essentially update the last blocking state and emit an event based on that phone number whether its valid so this contract is deployed on the test net and we can see here that i did deploy a graph so as we get new phone numbers on the app everything is indexed and its possible that uh phone numbers that were previously valid or previously invalid might switch so we take a time stamp of every single event that goes through and creates a record with showing when it was valid and where it originated in the world now because chain link is somewhat limited in terms of what we it can actually parse and this what the smart contract can actually do within the code i moved the logic of the api call into an external adapter now this is actually deployed as a lambda function but we have a single interface that is very simple for chain-link consume and its deployed as a function so i can just call it with the phone number as a path parameter it validates it uh but instead of throwing an uncaught exception if there was a bad phone number passed i have this default response that says okay theres no location associated with this phone number its not valid and i also have a flag thats numeric to indicate the validity so chain link actually consumes this response and makes it very easy to translate back into an event that can get emitted from the smart contract so there are a couple limitations right now right now we just support us addresses this is completely free service so you literally just pay the the gas cost um but it would be interesting to see what new possibilities accumulate as we get more and more phone numbers stored into this phone validator smart contract uh we could essentially do rapid lookups or cross validations uh with a with a global index of phone numbers that isnt tampered with or isnt maintained by any individual party um so theres a lot of different direction we can go all the code is open source the graph is deployed i encourage you to check it out and thanks for your time Veriphone is a project with the goal of creating the largest index of chainlink-validated phone numbers. The core contract, called PhoneValidator, stores and emits events for phone validations whenever the contract validate method is invoked. This contract is currently deployed on the testnet and can validate phone numbers using the requestValidatePhone method. Lookups are later indexed on for querying. Note this is in the prototype / proof of concept phase. chainlink thegraph hackathon 2020 blockchain blockchain,hackathon,2020,