Comparison
Crystor vs Proton Drive
Proton Drive is end-to-end encrypted storage in Proton's cloud, increasingly paired with Proton's own assistant. It's a coherent walled garden: their storage, their AI.
Crystor takes the other path. You keep the storage you already pay for (Dropbox, Google Drive, OneDrive, iCloud), the encryption and index run on your device, and the keyhole is an open standard (MCP), so it works with the AI you choose: ChatGPT, Claude, or the agent on your machine.