tivoization

Tivoization, named after the TiVo digital video recorders, is the practice of using hardware restrictions to prevent users from running modified versions of software on devices that include free software components, particularly those released under the GNU General Public License.

The term was popularized in the early 2000s by the Free Software Foundation to describe cases in which manufacturers distribute GPL-licensed software but implement hardware or firmware checks that block replacement of the original software, despite the software remaining legally modifiable. In such devices, a combination of cryptographic signatures, signed bootloaders, or tamper-resistant hardware can prevent users from booting their own modified versions of the software.

In TiVo’s original devices, Linux and other GPL components were deployed, but the hardware verified the identity of the software and refused to boot modified kernels unless the user possessed the original keys. This approach allowed manufacturers to deploy devices that include free software while denying user modification rights, highlighting a distinction between software freedom and hardware-level restrictions.

Tivoization prompted debates about the meaning of software freedom in the context of hardware devices. In response, the GPLv3 license draft and subsequent discussions introduced provisions intended to address such restrictions, aiming to ensure that recipients can modify and run modified versions of GPL-licensed software and, in distributed binaries, obtain the necessary installation information to do so.

See also: Free software, GPLv3, DRM, hardware restrictions.