Improving resilience of ActivityPub
Dissertation. Suggested and supervised by: Dr Anil Madhavapeddy. The idea was to introduce more inter-instance sharing into the ActivityPub protocol (decentralised social networking). Then, the data will be available even when some nodes fail. That should result in a better user experience and encourage more people to host their own instances, making the network more decentralised.
This was done by caching public keys of users in a newly designed Lookup server and having a decentralised network of verifiers to provide trust. Then, Public key cryptography was used to check the integrity of data coming from other instances. I forked Mastodon and modified it to use this system to provide the promised benefits.