| 摘要 |
A material distribution apparatus comprises a material server 1, 6 including a material impairment processor 34 operable to introduce a reversible impairment into the material to be distributed, and a communications network 2 operable to distribute the impaired material to at least one client processor 4. The client processor 4 comprises an impairment reversing processor 90 operable to reverse the impairment of the material to produce restored material. The material server 1,6 includes a material protection processor operable to introduce protection data into the material. The protection data is imperceptible in the material. The protection data serves to allow the detection of misuse of the material. Generating an impaired version of the material to be distributed provides a facility for a buyer to sample the material before acquisition, whilst discouraging the buyer from using the impaired material in an unauthorised way. If a buyer decides to acquire the material, the client processor is provided with impairment removal data. Other data, which is imperceptible in the material, may be introduced into the material. |
