MAPPING A GLYPH TO CHARACTER CODE IN OBFUSCATED DATA

In a font applying device on a client side in a computer system composed of the client and a server, an obfuscated font storing section stores an obfuscated font in which a character different from a character identified by the server based on a character code and having the same width of the character identified by the server is mapped to the character code. An obfuscated document receiving section receives an obfuscated document obtained by obfuscating document data as a result of converting the character code to a character code to which a character identified by the server based on the character code in the document data is mapped in the obfuscated font. A deobfuscation processing section identifies the character mapped in the obfuscated font to a character code included in the obfuscated document, and a display control section controls the display of the character.