EthCal

This project creates a way for an event planner to publish calendar events for their attendees without using their emails. Using the attendees wallet addresses, the event planner can send calendar invites like they normally would through GCal to [eth_addr]@[our_website].com. We publish these calendar events to the decentralized storage solution IPFS and provide a client for attendees to access and display their calendars.

This project uses IPFS to store .ics (calendar format) files. This technology allowed us to post encrypted event calendars that only users can decrypt with their Ethereum wallets, so that their events are both private and unable to be taken down by a third party. We used web3 clients on the front end to authenticate users and decrypt their calendar messages. Something particularly hacky that we employed was to encrypt the .ics files with the AES encryption standard and stored them along side the decryption key, which itself was encrypted based on the public key of the user's address. This allowed us to use a more efficient encryption scheme for our larger files while still ensuring Ethereum-level security.