Building a two-way linking of Ethereum address and Keybase usernames using KBFS and Oraclize Update: I have been working on a better flow for verifications, that will make the KBFS proof itself two way binding (by signing a proof with the Ethereum address private key). Update 2: New article has been published now: _Identity is one of the most important parts when developing decentralized applications. This is specially true for…_medium.com How Aragon approaches identity and the Ethereum Keybase Resolver When it comes to building decentralized apps, identity is important not only for but also for easily searching addresses with human readable and memorable strings. While might solve the later, it is also very important to be able to have further of who that person is. verification performing KYC ENS off-chain proofs is a service that allows for identity linking and verification using cryptographic proofs. recently introduced a cryptographically secure cloud storage. This allows users to have a public folder with files, and have a that only the user that owns the directory is allowed to put those files there. Therefore we can prove that an arbitrary piece of data was put there by a certain user. Keybase Keybase KBFS cryptographic proof Even though you can link a and Bitcoin address to your Keybase identity, at the moment there is no way to be certain that a user really controls the addresses listed, as no verification is required from the cryptocurrency part. Zcash When building Ethereum addresses verification for Keybase it is very important to provide , so applications can be certain that the address linked with your username is really yours. two-way verification Proposed registry implementation (KBFS + Registry contract) Using KBFS, a user can add a file to their public specifying the Ethereum address they want to verify. This is already a valid one-way proof, we know that only the user that owns the Keybase account, is specified a certain address. This is similar to what Keybase provides for BTC and Zcash right now. Then, the user performing the verification has to execute a function in the specifying their Keybase username they are trying to verify. The contract will then perform an to Keybase (using Oraclize) to fetch that user’s Ethereum address. registry smart contract from the address HTTP request If it matches, then the registry will create an entry for that user and address. The registry allows for two-way searching, that is username to address and address to username. Prove Ethereum address workflow (using Mist or Wallet) First, create a file named with the Ethereum address you want to link to your identity and save it to your KBFS public directory. That file will be publicly available at . Mine is . eth https://[username].keybase.pub/eth here Saving the eth file to KBFS Now you will have to watch the Keybase Registry contract in your wallet. From your wallet, go to contracts and click the “Watch contract” button. Add the contract address (the one deployed in the mainnet right now is: ) and the JSON interface for the contract that you can find . 0x390A6AB0684073ae6caBe6c390A43e87B117Ed0A here Watching the Keybase Registry contract Enter the contract and execute the ‘claim’ function. You will have to specify your (the one with the file) and send at least with it to pay for the (price at the day of writing, check for more info) Keybase username eth 0.005 ETH Oraclize call Oraclize pricing Executing the claim function And that’s it, as soon as the transactions are confirmed, you should be able to check your newly claimed username from the contract. You can find the source code for the initial implementation of the registry and see the currently deployed contract on . here Etherscan
