Hewlett-packard Development Company, L.p.

Erik Riedel

Ram Swaminathan

Mahesh Kallahalla

Christos Karamanolis

A technique for secure file access control via directory encryption. Filenames of data files stored by a network server are encrypted so as to protect them in the event the server is untrustworthy, such as in a distributed computing environment. Two encryption keys are employed so as to provide different access capabilities. For example, clients of the server that are authorized to perform read-only operations on the files may be prevented from modifying the files, while client that are authorized to perform write operations, may modify the files or even delete the files. In a preferred embodiment, encrypted filenames replace plaintext files in a directory structure without otherwise changing the directory structure. Because the directory structure is otherwise unchanged, the server may still have adequate information to perform file management and space management functions.

Secure file access control via directory encryption

A plurality of file encryption groups are created for a plurality of files based on attributes of each file. An event is detected and a selected file encryption group is divided into a plurality of sub-groups in response to the event. The division is based on an access pattern for each file in the selected file encryption group.

Optimizing costs associated with managing encrypted data

A plurality of users may have access to a file. The file is encrypted with a key. Access for a user to the file is revoked. A new key is generated from the current key of the file in response to said revocation, and the file is encrypted with the new key.

System for enabling lazy-revocation through recursive key generation

A security module is configured to provide an owner the capability to differentiate between users. In particular, the security module is configured to generate an asymmetric read/write key pair for respectively decrypting/encrypting data for storage on a disk. The owner of the file may distribute the read key of the asymmetric key pair to a group of users that the owner has assigned read-permission for the encrypted data.

System for ensuring data privacy and user differentiation in a distributed file system

A group manager module may provide the capability to segregate or associate files into file encryption groups. A file may be placed into a file encryption group based on the attributes of the file. The attributes may be characteristics/parameters that describe who has access to a file such as UNIX permission/mode bits (group-read/write/executable bit, owner-read/write/executable bits, users-read/write/executable bits) or other system for access control lists (ACLs). Once associated with a file encryption group, the file may be encrypted with the encryption (or write) key of the selected file encryption group, and thus, decrypted with the decryption (or read) key of the file encryption group. A user may have membership into multiple file encryption groups as long as the user possesses the appropriate read/write key pairs. Membership of a file in a file encryption group is determined automatically by the system based on the permission attributes assigned by the system&#x2014;groups are not explicitly created by administrators or other centralized authority. It is not users that belong to groups based on their access rights, but files which belong to groups based on their permission attributes.

System for optimized key management with file groups

A key management module is utilized to improve efficiency in cryptographic systems. The key management module may monitor file usage and recommend (and/or implement) key pair changes. In particular, the key management module may be configured to periodically examine (or analyze) performance parameters (e.g., number of times written, number of times read, etc.) associated with a user's files. A network monitor module may be configured to gather and maintain records of the associated performance parameters. The key management module may be further configured to compare the performance parameters of a given file with a table of key level ranges. The table of key lengths may be configured to provide a listing of multiple key lengths, each key length corresponding to an activity level of a performance parameter, e.g., relative read/write access frequency. The key management module may recommend changing the relative length of the read and write keys based on the comparison of the performance parameters with the table of key level ranges.

System for encrypted file storage optimization via differentiated key lengths

The present invention provides a split data and meta data distributed system operable to provide computer file services. The system includes a plurality of servers that include meta data servers and data servers. A client multicasts a message, including a request (e.g., a data request or a meta data request) to the plurality of servers in the system. The client considers the plurality of servers to be a single server instance. The servers may be divided into different subsets, and each subset is responsible for data requests or meta data requests. The servers that are responsible for the particular type of received request may respond to the request. Also, if multiple servers in a subset generate a request, the system may synchronize the responses, such that a single response, rather than multiple responses are transmitted to the client. This synchronization may not be necessary for responses to requests that do not change the stored state of the system.

Remote file system using network multicast

A method of and apparatus for migrating data between storage devices for reducing power consumption. Unlike prior techniques for conserving power by spinning down a magnetic disk (e.g., in a laptop computer), the present invention migrates data based on the assumption that the disk is maintained spinning (e.g., in a server). Accordingly, the incremental power consumed by maintaining data on the disk is nominal in comparison to the amount of power required to store the data in volatile memory (e.g., RAM). Data placement is largely based on the goal of minimizing power consumption during periods when the data is not being accessed. Further, unlike conventional techniques in which data is removed from RAM only when a better candidate is available to replace the data, the present invention may move data from RAM regardless of whether replacement data is available. This is avoids consumption of power to maintain data in RAM that is idle. Thus, under certain conditions, the inventive technique for data migration in a computer system reduces power consumption in comparison to conventional algorithms.

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San Francisco, CA, United States of America

Erik Riedel