Usage dependent ticket to protect copy-protected material

拷贝保护资料的每个拷贝带有一种使用限制。一致的重播设备确定该拷贝有多少使用，只在其使用在该拷贝相应的使用限制中时才播放该拷贝保护资料。在本发明的优选实施方案中，拷贝的供应来源包括一种使用总计量，在拷贝保护资料的每个拷贝间分配，从而允许生成拷贝保护资料的不止一个拷贝，或从供应来源的"检出"。当拷贝保护资料的一个拷贝随后被归还，或在供应来源"检入"，与这一拷贝相关的使用分配被归还到使用总计分配中。这样，如果该拷贝保护资料的某个拷贝丢失、损坏或被放错地方，对购买者的损失只是可用使用总计减少了一些。在优选实施方案中，与使用限制相关的参数通过加密方式复制资料进行传递。类似的，在优选实施方案中，与使用限制相关的参数被安全地绑定在拷贝保护资料上，这样非法的供应商不能用非法的资料替代拷贝的资料。其它的安全方法，如拷贝保护资料的加密、水印、标签，等等，都与以上提到的技术兼容，被包括在本发明的优选实施方案中。 A usage-limit is associated with each copy of copy-protected material. A conforming playback device determines how much usage has been made of the copy, and only plays the copy-protected material if the usage is within the associated usage-limit of the copy. In a preferred embodiment of this invention, the providing source of the copy contains a total-usage-measure that is allocated among each of the provided copies of the copy-protected material, thereby allowing for more than one copy of the copy-protected material to be produced, or "checked-out" from the providing source. When a copy of the copy-protected material is subsequently returned, or "checked-in" to the providing source, the usage allocation associated with this copy is returned to the total-usage-value. In this manner, if a particular copy, of the copy-protected material is lost, damaged, or misplaced, the loss of value to the purchaser is merely a reduction in the available total-usage. In a preferred embodiment, the parameters associated with the usage-limit are communicated via the copy of the material in a secure manner, so that an illicit provider cannot alter these parameters. Similarly, in a preferred embodiment, the parameters associated with the usage-limit are securely bound to the copy-protected material, so that an illicit provider cannot substitute illicit material for the copied material. Other security measures, such as an encryption of the copy-protected material, watermarking, ticketing, and the like, are also compatible with these aforementioned techniques, and are included in a preferred embodiment of this invention.