Tahoe-LAFS, the Least Authority File Store, is a decentralized storage system that features confidentiality, availability, and integrity of the data.
This is achieved by distributing your data across multiple servers. Tahoe offers "provider-independent security": the confidentiality and integrity of your data does not depend upon the behavior of the servers. Even if some of the servers fail or are taken over by an attacker, the entire file store continues to function correctly, preserving your privacy and security because all data is encrypted, erasure-coded, and hashed before leaving the client's machine.