Requiring user to verify the license, often by entering a
Product key in order to activate and use the software; some activation schemes require sending registration information over internet to prevent the same product key from being used by multiple users. In some cases, users are required to call a number to register and receive device-specific serial number.
Use of encrypted code together with
Secure cryptoprocessor so only the machine with cryptoprocessor could execute the program; used in systems that require high security such as ATMs.
A file with activation key that needs to be installed in same directory as software; similarly, a disc media (often installation disc) may be required as key disk for activation.[1]
The encrypted content can only be decrypted using combination of media key (obtained from
Media Key Block by one of device keys available for each reproduction devices) and the Volume ID (unique identifiers stored on each disk) of the media.
The BD+ virtual machine embedded in authorized players will execute programs included in Blu-ray discs, allowing to verify the player's keys, transform the output so that content is unscrambled, and/or execute native code to patch the system against vulnerabilities. Based on concept of
self-protecting digital content.
Transmitting device checks before sending that receiver is authorized to receive the data. The data is encrypted during transmission to prevent eavesdropping.
Rather than directly preventing copying, embeds user information into files so if they are uploaded, the copyright holder could find out exactly who uploaded the file.
Inserts a waveform into the non-picture Vertical Blanking Interval (VBI) of the analog video signal so compatible device can block or restrict recording when the waveform is detected.