Emc Corporation

Yedidia Atzmony

Josef Ezra

Haim Kopylovitz

Sachin More

Hana Moreshet

Ron Arnan

Yechiel Yochai

Philip E Tamer

Dennis F Flanagan

David J Allen

Daniel Lambright

Hagit Brit-Artzi

Adel Hanna

Arnold E Adelman

David I Levinson

DeAnn L O'Hare

Access to a target system is secured by use of an encrypted passphrase that is supplied on-site at the target system by a user requesting access. The encrypted passphrase includes an access credential portion and a one-way encoded portion. The one-way encoded portion is an encoded version of at least some of the access credential portion. A validator at the target system receives and decrypts the encrypted passphrase and identifies the access credential portion and one-way encoded portion. The validator one-way encodes the identified access credential portion and compares the result to the identified one-way encoded portion from the decrypted passphrase. If the results do not match, the validator denies access to the user requesting access. The encoding and decrypting of the passphrase may be performed using keys generated from a secret key/seed related to the target system, unencrypted information such as time/date information, and a user PIN.

Securing a passphrase

Restricting access to a device includes obtaining a passphrase for a user, obtaining access credentials for the user, obtaining a PIN value for the user, one-way encrypting at least the access credentials and the PIN using a secret key provided with the device. The user is allowed access to the device if the result of one-way encrypting equals the passphrase. The user is denied access to the device if the result of one-way encrypting does not equal the passphrase. The device may be a storage device. The access credentials may include a username that identifies the user and may include a role for the user. The access credentials may include a time period for which access is allowed. Access may be subsequently revoked in response to the current date and time being greater than the time period for which access is allowed.

Accessing data storage devices

A method for copying data from a source logical device to a destination logical device. In response to a copy command from a requesting host application identifying the source and destination logical devices, an environment is established. Thereafter a calling system receives an immediate response that the copy operation is complete even though no data has been copied. Application programs may access storage locations in either the source or the destination logical device during the copy phase. A copy program transfers the date on a track-by-track basis to the destination logical device. Procedures assure that any data access to a particular track in either the source or destination logical device by any application prior to the transfer of that track is accommodated to maintain data integrity.

Method and apparatus for making independent data copies in a data processing system

Described are techniques and criteria used in connection with cache management. The cache may be organized as a plurality of memory banks in which each memory bank includes a plurality of slots. Each memory bank has an associate control slot that includes groups of extents of tags. Each cache slot has a corresponding tag that includes a bit value indicating the availability of the associated cache slot, and a time stamp indicating the last time the data in the slot was used. The cache may be shared by multiple processors. Exclusive access of the cache slots is implemented using an atomic compare and swap instruction. The time stamp of slots in the cache may be adjusted to indicate ages of slots affecting the amount of time a particular portion of data remains in the cache.

Cache management via statistically adjusted time stamp queue

The cache arrangement includes a cache that may be organized as a plurality of memory banks in which each memory bank includes a plurality of slots. Each memory bank has an associated control slot that includes groups of extents of tags. Each cache slot has a corresponding tag that includes a bit value indicating the availability of the associated cache slot, and a time stamp indicating the last time the data in the slot was used. The cache may be shared by multiple processors. Exclusive access of the cache slots is implemented using an atomic compare and swap instruction. The time stamp of slots in the cache may be adjusted to indicate ages of slots affecting the amount of time a particular portion of data remains in the cache. Associated with each processor is a unique extent increment used to determine a next location for that particular processor when attempting to locate an available slot.

Advancing bank pointer in prime numbers unit

Growing community of inventors

Newton, MA, United States of America

Yedidia Atzmony