SRI International Receives Security Technology Patent for Paper-Based Transactions

"Nonce Stamp" Offers Many Applications, Including Electronically Downloaded Airline Tickets, Travelers' Checks, Passports, Postage, Legal Documents, and Event and Movie Tickets

MENLO PARK, Calif. - November 23, 2004 - SRI International, a leading independent, nonprofit research institute known for its pioneering innovations, today announced it has been issued a fundamental U.S. patent for its "nonce stamp" technology, which can secure and authenticate paper documents against fraudulent creation and use.

U.S. Patent No. 6,820,201 covers SRI's information-based indicia technology for securing and authenticating paper documents. The SRI technology addresses the security issues inherent in today's popular "print-at-home" documents, such as postage and movie tickets, which can be readily counterfeited.

The recently awarded patent and related pending SRI patents cover an innovative use of a nonce (an element used to protect electronic cryptography systems from being cracked) to protect paper-based documents. The nonce is a unique number preprinted on a forgery-resistant material. When the user wishes to print an article of value, such as a postage stamp, the value of the nonce is combined with other information (e.g., the value of the postage) and a digital certificate is created. The digital certificate, in electronic or printed form, together with the nonce stamp, provides cryptographically secure proof of the uniqueness and authenticity of the certificate.

The inventors are laboratory director Patrick D. Lincoln, Ph.D., and staff scientist Natarajan Shankar, Ph.D., of SRI's Computer Science Laboratory. "Most paper currency and other documents that have monetary value include security features to prevent fraud. SRI saw the need to also secure today's popular "print-at-home" documents to eliminate forgery and counterfeiting," said Dr. Lincoln. "Nonce stamps are a way of creating unique physical representations of digital certificates that are easily authenticated and that cannot be forged."

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About SRI International

Silicon Valley-based SRI International (http://www.sri.com) is one of the world's leading independent research and technology development organizations. Founded as Stanford Research Institute in 1946, SRI has been meeting the strategic needs of clients for more than 55 years. The nonprofit research institute performs contract research and development for government agencies, commercial businesses and private foundations. In addition to conducting contract R&D, SRI licenses its technologies, forms strategic partnerships and creates spin-off companies.

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