A technique for secure network storage includes generating, by a trusted execution environment in a first device, an encryption key and a certificate for a document, wherein the certificate comprises expiry information for the document and the encryption key, encrypting, by a general execution environment in the first device, the document with the encryption key, transmitting the encryption key to a remote key manager, and transmitting the document to a remote network storage device, wherein a second device is allowed to decrypt the document based on the expiry information.