peer - to - peer file sharing is increasing in popularity on the internet , faster than any product known in history . although file - sharing can enable massive piracy , it has many advantages for distribution of information including scalability . alternatively , file - sharing can be sabotaged with falsified files and used to distribute viruses . to this end , a solution that maintains the scalability of file - sharing and promotes reliability is proposed . the solution involves embedding data within the file or content and using the data to identify the content , demonstrate its completeness and lack of viruses , and verify the file can be shared . the embedded data can be checked when the file is registered with the database for sharing , and before or while the file is being uploaded and / or downloaded . ideally , the embedded data is added at the time of creation for the file . the embedded data may include a watermark and be linked to other copy management systems , such as those proposed in dvd and sdmi . finally , the embedded data can be used to enable purchases of files that owners do not have rights to share .