Abstract: Various exemplary embodiments relate to a system for storing encrypted data and providing access to a group of users. The system may include: a record of user accounts including: a user identifier and a public encryption key; an access control list (ACL) defining an access control policy including: permissions defining access to data objects associated with the ACL and an ACL key list including copies of a an ACL key encrypted with the public keys of the users; a user-data storage medium including: encrypted user data, stored as a plurality of data objects, each object associated with an ACL and encrypted with the ACL key, and meta-data; and an access controller configured to: receive a request for a data object, and send a copy of the data object and the ACL key encrypted with the public key of the user if the user has permission to access the data object.

Abstract: Various exemplary embodiments relate to a system for storing encrypted data and providing access to a group of users. The system may include: a record of user accounts including: a user identifier and a public encryption key; an access control list (ACL) defining an access control policy including: permissions defining access to data objects associated with the ACL and an ACL key list including copies of a an ACL key encrypted with the public keys of the users; a user-data storage medium including: encrypted user data, stored as a plurality of data objects, each object associated with an ACL and encrypted with the ACL key, and meta-data; and an access controller configured to: receive a request for a data object, and send a copy of the data object and the ACL key encrypted with the public key of the user if the user has permission to access the data object.