Technological protection measures (TPM) are any digital management tools used to restrict what users can do with digital materials. TPM are defined in Canada's Copyright Act as

any effective technology, device or component that, in the ordinary course of its operation, (a) controls access to a work, to a performer's performance fixed in a sound recording or to a sound recording and whose use is authorized by the copyright owner; or (b) restricts the doing - with respect to a work, to a performer's performance fixed in a sound recording or to a sound recording - of any act [which only the copyright owner has the right to do or authorize]. (s.41)

Technological Protection Measures are generally put in place by the copyright holder or content provider (i.e. website owner) to control the ways in which that content can be used.

The Copyright Act prohibits the circumvention of a TPM, even if what you would like to do with the work would not otherwise infringe copyright (except in the case of copying a work in order to make it accessible for someone with a perceptual disability). For example, although an instructor in an educational institution is allowed to copy an article, photograph or other work from the Internet and communicate it to students, they cannot do so if copying is blocked on that particular work or site.

What are technological protection measures?

TPM may also be called digital locks or digital rights management (DRM).

There are two types of TPM:

1. access control measures, which restrict access to a work, and
2. copy control measures, which restrict what can be done with the work.

Examples of access control TPM include

• passwords,
• paywalls or subscriptions,
• registration keys,
• time limits (e.g. 48-hour movie rental),
• limits on the number of simultaneous users (e.g. library ebooks),
• encryption/scrambling (e.g. regional encoding on DVDs, IP blocking based on location) and
• selective incompatibility (e.g. a CD that will read in a CD player but not a computer CD drive).

Examples of copy control TPM include

• read-only works (e.g. ebooks),
• download blocking (e.g. streaming content),
• copy blocking (e.g. digital music and movies),
• print blocking,
• labeling and
• watermarks.