The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 1997
Filed:
Jun. 29, 1995
Allan E Alcorn, Portola Valley, CA (US);
Michael Barnett, Santa Clara, CA (US);
Louis D Giacalone, Jr, Palo Alto, CA (US);
Adam E Levinthal, Redwood City, CA (US);
Silicon Gaming, Inc., Palo Alto, CA (US);
Abstract
An electronic casino gaming system includes an unalterable ROM for storing a casino game authentication program, including a message digest algorithm program, a decryption program and a decryption key. A casino game data set containing casino game rules and image data is stored in a mass storage device, such as a local disk memory or a remote network file server, along with the signature of the casino game data set. The signature is an encrypted version of the message digest of the casino game data set, prepared using a hash function. Prior to permitting game play by a player, the casino game data set is transferred from the mass storage device to main memory and during this process the message digest is computed from the image data using a hash function stored in the ROM. The encrypted version of the message digest transferred from the mass storage device is decrypted using the decryption program and decryption key stored in the unalterable ROM. The two message digests are then compared for a match: if a match exists, game play is permitted; if a match does not exist, game play is prohibited. The authentication procedure is also used to check all casino game software, both programs and fixed data sets, stored in any memory devices distributed throughout the system, such as the system boot ROM, NVRAM and all sub-system memory devices. The authentication procedure is run whenever a particular program or fixed data set is scheduled for use by the system, and also at periodic intervals and on demand.