Before revision: Providers of zero-knowledge services include: SpiderOak Tresorit Sync.com NordPass Cubbit ProtonMail Signal LucidLink Disadvantages Most cloud storage services keep a copy of the client's password on their servers, allowing clients who have lost their passwords to retrieve and decrypt their data using alternative means of authentication; but since zero-knowledge services do not store copies of clients' passwords, if a client loses their password then their data cannot be decrypted, making it practically unrecoverable.
After revision: Providers of zero-knowledge services include: Cubbit LucidLink NordPass ProtonMail Signal SpiderOak Sync.com Tresorit Tarsnap Disadvantages Most cloud storage services keep a copy of the client's password on their servers, allowing clients who have lost their passwords to retrieve and decrypt their data using alternative means of authentication; but since zero-knowledge services do not store copies of clients' passwords, if a client loses their password then their data cannot be decrypted, making it practically unrecoverable.