DIY Hosting for Online Privacy

Abstract

Web users today rely on centralized services for applications such as email, file transfer and chat. Unfortunately, these services create a significant privacy risk: even with a benevolent provider, a single breach can put millions of users' data at risk. One alternative would be for users to host their own servers, but this would be highly expensive for most applications: a single VM deployed in a high-availability mode can cost many dollars per month. In this paper, we propose Deploy It Yourself (DIY), a new model for hosting applications based on serverless computing platforms such as Amazon Lambda. DIY allows users to run a highly available service with much stronger privacy guarantees than current centralized providers, and at a dramatically lower cost than traditional server hosting. DIY only relies on the security of container isolation and a key manager as opposed to the large codebase of a high-level application such as Gmail (and all the Google teams using Gmail data). With attestation technology such as SGX, DIY's execution could also be verified remotely. We show that a DIY email server that sends 500 messages/day costs $0.26/month, which is 50x cheaper than a highly available EC2 server. We also implement a DIY chat service and show that it performs well. Finally, we argue that DIY applications are simple enough to operate that cloud providers could offer a simple "app store" for using them.