Sentence recognition device, text recognition method, and program

The character code conversion apparatus 10, instead of the standard character code table, using the converted character code table obtained by converting the standard character code table, the conversion character code string showing the sentence to be transmitted over the network N sentence recognition apparatus 20 to send to. Thus, even if the acquired converted character code string to a third party, for standard character code table is used, the character string to be identified from the conversion character code string becomes a thing altogether different from the sentence to be transmitted, to recognize the sentence to be transmitted becomes difficult. As a result, it is possible to improve the safety of the sentence to be transmitted.