Computer software protection.

摘要

A master copy 6 of a software file has within it a predetermined block of data 8. When a copy of the file is made that block of data within the copy file is located and overwritten with data identifying the copy file 12. When an unauthorised copy file is found the data identifying the copy file can be read and the source of the unauthorised copy may be traced. The invention is particularly suited to use with software distribution over a computer network in which details such as the time the copy file was made and the name of the authorised user can be embedded within the copy file. <IMAGE>