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.