Contents use frequency limiting method, contents using terminal apparatus, contents using system, computer program and computer readable memory medium

摘要

In a terminal device utilizing contents-having a limitation in the use frequency, an encrypted electronic file containing the contents is decrypted, then the decrypted electronic file is interpreted and the contents are outputted in a usable form. A set of an encryption key and a decryption key is generated at or after the output of the contents, then the decrypted electronic file is re-encrypted with the generated encryption key, and the re-encrypted electronic file is stored while the generation decryption key is outputted.