| 摘要 |
<p>Digital information is held in a piece of hardware having a durability so as to protect the digital information. A record concerning transfer of digital information, namely, a transfer history is made in a system in which digital information is transferred without permitting duplication using a hardware mechanism. Analysis of the transfer history enables determination when digital information is copied by altering the hardware. Because the data structure of the transfer history is a nested structure, the computational complexity of the computation for transfer history inspection necessary for a transfer is a constant independent of the number of transfers, and the durability against false alteration of a transfer history by an authorized user during the distribution.</p> |
