Media
Contact:
Michael
E. Newman, (301) 975-3025
Technology
Innovation
The Future of
Bridge Design? Plastics Says ATP Partner
Plastic
bridges? Believe it. Or more properly fiber-reinforced polymer
(FRP) composite bridges. The latest onespanning Dicky
Creek in Sugar Grove, Va.was just dedicated last month. One
of the longest FRP bridges to date, the Sugar Grove structure is a
12-meter (38-foot), two-lane, clear-span bridge supported by eight
92-centimeter (36-inch) deep composite beams supplied by Strongwell
Corp. of Bristol, Va. The bridge, say designers, meets US standards
for a bridge capable of carrying full tractor-trailer traffic.
A major issue
for widespread use of polymer composites is the ability to manufacture
the large composite beams at a cost competitive with steel. Strongwells
unique beams, strengthened with a combination of glass and carbon
fibers, were developed under a NIST Advanced Technology Program (ATP)
project to enhance the mechanical properties of the material, optimize
beam shape, and establish design standards and load capacities.
Bridge engineers
have high hopes for the future of polymer composite bridges. Composite
beams can be much lighter and stronger than the steel beams they replace,
and easier and faster to install (because of their light weight.)
Even better, they are expected to be considerably more durable and
maintenance-free than steel. Durability is a major benefitFederal
Highway Administration (FHWA) studies indicate that nearly 30 percent
of US bridges are obsolete or structurally deficient, and that bridge
maintenance/repair is a major expense for many state and local transportation
departments.
The Dicky Creek
bridge was constructed as a joint project by Strongwell, the FHWA
Innovative Bridge Research and Construction Program, the Virginia
Department of Transportation and Virginia Tech University. Researchers
from Virginia Tech installed special equipment to monitor the bridge
over the next year.
More information
on the NIST ATP can found at www.atp.nist.gov;
the Innovative Bridge Research and Construction Program at www.fhwa.dot.gov/bridge/ibrc.htm;
and Strongwell Corp. at www.strongwell.com.
Media
Contact:
Michael
Baum, (301) 975-2763
Computer
Security
AES Becomes Federal
Standard for Encrypting Data
On
Dec. 4, 2001, Commerce Secretary Don Evans approved Federal Information
Processing Standard (FIPS) 197 that makes the Advanced Encryption
Standard (AES) the official government encryption tool for protecting
sensitive, unclassified information well into the 21st century. The
new standard also is expected to be used widely in the private sector,
benefiting millions of consumers and businesses.
The approval of
FIPS 197 marks the culmination of a four-year effort by computer scientists
at NIST to secure and implement a highly secure algorithm for the
AES. This was done through an international competition, starting
in September 1997, in which researchers from 12 different countries
submitted encryption algorithms. Fifteen candidate formulas chosen
by NIST in August 1998 were attacked for vulnerabilities
and intensely evaluated by the worldwide cryptographic community to
ensure that they met the AES criteria. After the field was narrowed
down to five in April 1999, NIST asked for intensified attacks and
scrutiny on the finalists. Evaluations of the encoding formulas examined
factors such as security, speed and versatility.
The algorithm
selected for the AES in October 2000 incorporates the Rijndael (pronounced
Rhine-doll) encryption formula. It supports key sizes
of 128, 192 and 256 bits. For a 128-bit key size, there are approximately
340 undecillion (340 followed by 36 zeros) possible keys.
The AES replaces
the aging Data Encryption Standard (DES), which NIST adopted in 1977
as the federal encryption standard. DES and a variant called Triple
DES have been used widely in the private sector as well.
Products implementing
the AES are expected to be available shortly in the marketplace. NIST
also is completing arrangements so that vendors can have their implementations
of AES validated under the Cryptographic Module Validation Program,
jointly led by NIST and the Government of Canadas Communications
Security Establishment. Validation helps ensure that the complex AES
algorithm has been implemented correctly. Private-sector accredited
laboratories conduct this testing, which then is validated by NIST
and CSE. For more details see http://csrc.nist.gov/cryptval/.
Detailed information
about the development of the AES, and the standard itself, is available
at www.nist.gov/aes.
Media
Contact:
Philip
Bulman, (301) 975-5661