End-to-Same-End Encryption: Modularly Augmenting an App with an Efficient, Portable, and Blind Cloud Storage
No ratings
Presented at USENIX Security 2022 by
The cloud has become pervasive, and we ask: how can we protect cloud data against the cloud itself? For messaging Apps, facilitating user-to-user private communication via a cloud server, security has been formulated and solved efficiently via End-to-End encryption, building on existing channels between end-users via servers (i.e., exploiting TLS, certificates, and encryption, without the need to program new primitives). However, the analogous problem for Apps employing servers for storing and retrieving end-user data privately, solving the analogous "privacy from the server itself" (cloud-blind storage) where (1) based on existing messaging/infrastructure and (2) allowing user mobility, is, in fact, still open. Existing proposals, like password protected secret sharing (PPSS), target end-to-same-end encryption of storage, but need new protocols, whereas most popular commercial cloud storage services are not programmable. Namely, they lack the simplicity needed for being portable over any cloud storage service.