Zettaset Assigned Patent

Zettaset, Inc., Mountain View, CA, has been assigned a patent (10,298,555) developed by Murray, Eric A., Los Gatos, CA, for “securing files under the semi-trusted user threat model using per-file key encryption.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A computer system and methods for securing files in a file system with storage resources accessible to an authenticable user using an untrusted client device in a semi-trusted client threat model. Each file is secured in the file system in one or more ciphertext blocks along with the file metadata. Each file is assigned a unique file key FK to encrypt the file. A wrapping key WK assigned to the file is used for encrypting the file key FK to produce a wrapped file key WFK. The file is encrypted block by block to produce corresponding ciphertext blocks and corresponding authentication tags. The authentication tags are stored in the file metadata, along with an ID of the wrapping key WK, wrapped file key WFK, last key rotation time, an Access Control List, (ACL), etc. The integrity of ciphertext blocks is ensured by authentication tags and the integrity of the metadata is ensured by a message authentication code, (MAC).”

The patent application was filed on May 31, 2016 (15/168,332).