Lawrence J Chang

US Patent:

7167530, Jan 23, 2007

Filed:

Jan 13, 2003

Appl. No.:

10/342198

Inventors:

George P. Koomullil - Hayward CA, US
Lawrence K. Chang - Sunnyvale CA, US

Assignee:

RF Micro Devices, Inc. - Greensboro NC

International Classification:

H04L 27/00

US Classification:

375329, 375319

Abstract:

Systems and methods for estimating and correcting a DC offset in a receiver in the presence of a carrier frequency offset. Samples corresponding to a transmitted signal are received. Each sample is corrected for a carrier frequency offset. An average value is computed for a training sequence of the corrected samples, where the training sequence has a known DC offset. The average value is adjusted using an adjustment factor that reflects an effect on the DC offset of the act of correcting for a carrier frequency offset, thereby generating a DC offset estimate.

US Patent:

7958356, Jun 7, 2011

Filed:

Sep 29, 2006

Appl. No.:

11/540441

Inventors:

Ananthan Subramanian - Menlo Park CA, US
Robert Jan Sussland - San Francisco CA, US
Lawrence Wen-Hao Chang - San Francisco CA, US

Assignee:

NetApp, Inc. - Sunnyvale CA

International Classification:

H04L 9/32
H04L 9/00
H04L 9/08
H04L 9/12

US Classification:

713171, 713150, 713162, 713163, 713168, 713181, 713182, 380229, 380 28, 380 30, 380227, 380278, 380282

Abstract:

A system and method securely establishes a shared secret among nodes of a security appliance. The shared secret is established by distributing private keys among the nodes in accordance with a node ring protocol that uses a predetermined encryption algorithm to generate messages containing the keys. Briefly, each node is initially notified as to the number of nodes participating in the shared secret establishment. Each node generates a public-private key-pair, as well as a first message that includes the generated public key and an indication of the source of the generated public key (hereinafter “source generated public key”). The node then sends the first message to an adjacent node of the appliance. Upon receiving the first message, each node extracts the source generated public key from the message and stores the extracted information into a data structure of “partner” public keys. The protocol then continues with each node generating additional messages equal to the number of participating nodes minus one.

US Patent:

7971234, Jun 28, 2011

Filed:

Sep 15, 2006

Appl. No.:

11/532468

Inventors:

Robert Sussland - Redwood City CA, US
Lawrence Chang - Redwood City CA, US
Ananthan Subramanian - Redwood City CA, US
Joshua Silberman - Redwood City CA, US

Assignee:

NetApp, Inc. - Sunnyvale CA

International Classification:

G06F 15/16

US Classification:

726 5, 726 7, 713168

Abstract:

The invention provides an authentication scheme that allows networked devices to establish trust in connection with the exchange of keys pursuant to an asymmetrical cryptographic technique, such as Diffie-Hellman. The invention provides a technique, referred to as offline key establishment, that establishes a trust relationship between two networked devices that use Diffie-Helman. Offline key sharing provides for the exchange of authentication information using a separate channel which, in the preferred embodiment does not constitute an IP connection. Thus, while communications between networked devices may ultimately proceed via a network connection, trust between the networked devices is established via a separate, offline channel, such as a telephone call or email message. The use of offline key establishment allows for such features as one way key sharing; and addresses situations where one party to the exchange does not want to share all of his keys, but just one or two keys.

US Patent:

8245050, Aug 14, 2012

Filed:

Sep 29, 2006

Appl. No.:

11/540440

Inventors:

Ananthan Subramanian - Menlo Park CA, US
Lawrence Wen-Hao Chang - San Francisco CA, US

Assignee:

NetApp, Inc. - Sunnyvale CA

International Classification:

H04L 29/06

US Classification:

713183, 713182, 713184, 713150, 713151, 713168, 726 2, 726 3, 726 27, 380278, 380281, 380277

Abstract:

A split knowledge protocol adapted to establish an initial key for use in authenticating a first computer to a second computer. The second computer initiates the split knowledge protocol by generating a bit sequence and splitting the sequence into a predetermined number of segments. The second computer then encrypts each segment with a predetermined key associated with each segment before transmitting each encrypted segment to the first computer. In response, the first computer decrypts each encrypted segment using the associated key. The first computer then recovers the bit sequence from the decrypted segments. Accordingly, the first and second computers have knowledge of (i. e. , access to) the same bit sequence, which may thus be used as the initial key.

US Patent:

8285993, Oct 9, 2012

Filed:

Apr 22, 2011

Appl. No.:

13/092371

Inventors:

Ananthan Subramanian - Menlo Park CA, US
Robert Jan Sussland - San Francisco CA, US
Lawrence Wen-Hao Chang - San Francisco CA, US

Assignee:

NetApp, Inc. - Sunnyvale CA

International Classification:

H04L 29/06

US Classification:

713171, 713150, 713162, 713163, 713168, 713181, 713182, 380229, 380 28, 380 30, 380277, 380278, 380282, 709223, 709224, 709225

Abstract:

A method for distributing a shared secret key among a plurality of nodes is described. Each node establishes a secret key, the number of nodes being more than two nodes. A node distributes by a ring protocol executing over computer network connections an encrypted version of the secret key of each node to other nodes of the plurality of nodes. Each node decrypts the secret keys of other nodes so that each node has the secret key of other nodes. Each node combines the secret keys of other nodes to form a shared secret key available to other nodes.

US Patent:

8478777, Jul 2, 2013

Filed:

Oct 25, 2011

Appl. No.:

13/280582

Inventors:

Yang Li - Palo Alto CA, US
Leo Chiow-Fuan Ting - Sunnyvale CA, US
Rui Ueyama - Mountain View CA, US
Lawrence Chang - Foster City CA, US
Younghun An - San Jose CA, US

Assignee:

Google Inc. - Mountain View CA

International Classification:

G06F 17/30

US Classification:

707769

Abstract:

In general, the subject matter described in this specification can be embodied in methods, systems, and program products for performing searches with gesture-based input. A search system receives gesture data corresponding to one or more characters that have been drawn on a display of a client device. The search system recognizes the one or more characters that correspond to the gesture data. The search system formulates a search that includes the one or more characters as a query term. The search system communicates to the client device one or more search results for the search, and data identifying the one or more characters.

US Patent:

61785334, Jan 23, 2001

Filed:

Jun 30, 1997

Appl. No.:

8/885160

Inventors:

Lawrence L. Chang - Palo Alto CA

Assignee:

Sun Microsystems, Inc. - Mountain View CA

International Classification:

G01R 3128

US Classification:

714739

Abstract:

The present invention pertains to a dynamic process for generating biased pseudo-random test patterns for the functional verification of a microprocessor having a bus interface unit that is capable of direct memory access (DMA) operations between I/O devices attached to an external bus and the microprocessor's memory. The test patterns verify memory operations performed by the microprocessor and DMA operations received by the microprocessor's bus interface unit. These test patterns can then be used by a simulation mechanism to simulate the expected results of the target microprocessor running the generated sequence of transactions. The test verification system categorizes the verifiable operations into transactions. Each transaction is assigned a user-defined weight that is used to bias the frequency that a transaction is tested. The test verification system selects a particular transaction category based on the user-defined weights and generates the corresponding instructions or test patterns that implement the transaction.

US Patent:

20210271567, Sep 2, 2021

Filed:

Feb 26, 2021

Appl. No.:

17/187286

Inventors:

- Sunnyvale CA, US
Woonho Jung - Cupertino CA, US
Xia Hua - Mountain View CA, US
Douglas Qian - Mountain View CA, US
Rajeev Kumar - Sunnyvale CA, US
Lawrence Chang - San Jose CA, US
Karan Dhabalia - Mountain View CA, US
John Stewart - San Jose CA, US
Rolland Miller - Olathe KS, US

International Classification:

G06F 11/14

Abstract:

Techniques are disclosed relating to the storage of backup data using a time-series data lake. For example, in various embodiments, the disclosed techniques include providing a cloud-based data lake service that maintains data for a plurality of organizations and where, for a first organization, the cloud-based data lake service maintains a time-series data lake that stores a time-series representation of data associated with the first organization. In various embodiments, the data lake service may receive backup data from a plurality of data sources associated with the first organization, generate metadata associated with the backup data, and store the backup data, along with the corresponding metadata, in the time-series data lake.