Engineering topics

Eldridge, John M

Publications and source records attributed to Eldridge, John M.

4 records

DOE OSTI2014

Stateless and stateful implementations of faithful execution

A faithful execution system includes system memory, a target processor, and protection engine. The system memory stores a ciphertext including value fields and integrity fields. The value fields each include an encrypted executable instruction and the integrity fields each include an encrypted integrity value for determining whether a corresponding one of the value fields has been modified. The target processor executes plaintext instructions decoded from the ciphertext while the protection engine is coupled between the system memory and the target processor. The protection engine includes logic to retrieve the ciphertext from the system memory, decrypt the value fields into the plaintext instructions, perform an integrity check based on the integrity fields to determine whether any of the corresponding value fields have been modified, and provide the plaintext instructions to the target processor for execution.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2011

SpaceWire model development technology for satellite architecture.

Packet switched data communications networks that use distributed processing architectures have the potential to simplify the design and development of new, increasingly more sophisticated satellite payloads. In addition, the use of reconfigurable logic may reduce the amount of redundant hardware required in space-based applications without sacrificing reliability. These concepts were studied using software modeling and simulation, and the results are presented in this report. Models of the commercially available, packet switched data interconnect SpaceWire protocol were developed and used to create network simulations of data networks containing reconfigurable logic with traffic flows for timing system distribution.

33 ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2011

Joint Architecture Standard (JAS) Reliable Data Delivery Protocol (RDDP) specification.

The Joint Architecture Standard (JAS) program at Sandia National Laboratories requires the use of a reliable data delivery protocol over SpaceWire. The National Aeronautics and Space Administration at the Goddard Spaceflight Center in Greenbelt, Maryland, developed and specified a reliable protocol for its Geostationary Operational Environment Satellite known as GOES-R Reliable Data Delivery Protocol (GRDDP). The JAS program implemented and tested GRDDP and then suggested a number of modifications to the original specification to meet its program specific requirements. This document details the full RDDP specification as modified for JAS. The JAS Reliable Data Delivery Protocol uses the lower-level SpaceWire data link layer to provide reliable packet delivery services to one or more higher-level host application processes. This document specifies the functional requirements for JRDDP but does not specify the interfaces to the lower- or higher-level processes, which may be implementation-dependent.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2010

Cyber security analysis testbed : combining real, emulation, and simulation.

Cyber security analysis tools are necessary to evaluate the security, reliability, and resilience of networked information systems against cyber attack. It is common practice in modern cyber security analysis to separately utilize real systems of computers, routers, switches, firewalls, computer emulations (e.g., virtual machines) and simulation models to analyze the interplay between cyber threats and safeguards. In contrast, Sandia National Laboratories has developed novel methods to combine these evaluation platforms into a hybrid testbed that combines real, emulated, and simulated components. The combination of real, emulated, and simulated components enables the analysis of security features and components of a networked information system. When performing cyber security analysis on a system of interest, it is critical to realistically represent the subject security components in high fidelity. In some experiments, the security component may be the actual hardware and software with all the surrounding components represented in simulation or with surrogate devices. Sandia National Laboratories has developed a cyber testbed that combines modeling and simulation capabilities with virtual machines and real devices to represent, in varying fidelity, secure networked information system architectures and devices. Using this capability, secure networked information system architectures can be represented in our testbed on a single, unified computing platform. This provides an 'experiment-in-a-box' capability. The result is rapidly-produced, large-scale, relatively low-cost, multi-fidelity representations of networked information systems. These representations enable analysts to quickly investigate cyber threats and test protection approaches and configurations.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗