Fujitsu Corporation

Satoshi Komura

Kenichi Utsumi

Satoshi Itami

Hiroshi Suzuki

Kazuo Nakashima

Masahiro Nakada

Kazunori Naito

Takashi Tsubokura

Masaru Nakahara

Kyouko Miyabe

A method of preventing a fraudulent use of an optical disk having a read-write region and a read-only region, comprising the steps of: writing data for designating the boundary between the read-write region and the read-only region into a predetermined block of the optical disk; reading the data out of the predetermined block prior to the execution of the software recorded on an optical disk as an object of fraudulent use check; reading data out of a block which is assumed to be in the read-only region by reference to the data read out of the predetermined block, and writing the data read out of the block in the assumed read-only region into the same block; reading data out of a block which is assumed to be in the read-write region by reference to the data read out of the predetermined block, and writing the data read out of the block in the assumed read-write region into the same block; and judging that the optical disk as an object of fraudulent use check is not a fraudulent copy when the data writing operation is impossible in the block in the assumed read-only region but possible in the block in the assumed read-write region.

Optical disk and method of preventing fraudulent use of optical disk

A character string retrieval system retrieves a character string corresponding to a retrieval key input thereto from a text file including a plurality of characters. The system includes an index indicating position data identifying a position of each of characters in the text file and indicating next character data identifying either a character or a character string formed of a plurality of characters arranged next to each of the characters in the text file, a selecting unit for selecting a first character from characters forming the character string corresponding to the retrieval key, a determining unit for determining, with reference to said index, whether or not a character or a character string next to the first character, selected by said selecting unit, in the retrieval key is equal to a character or a character string identified by the character data corresponding to the first character; and output unit for outputting a retrieval result when said determining unit determines that a character or a character string next to the first character in the retrieval key is equal to a character or a character string identified by the character data corresponding to the first character, the retrieval result being obtained based on the position data corresponding to the first character in said index.

Character string retrieval system using index and unit for making the

Growing community of inventors

Kawasaki, Japan

Satoshi Komura