A digital watermark is a kind of marker covertly embedded in data and is also sometimes referred to as the practice of imperceptibly altering a work to embed a message about that work. This technique allows to track datasets upon sharing data with 3rd parties.
For Semantic Container a digital watermark is a unique digital fingerprint that is applied to data provided by a Semantic Container, i.e., any data request results in a dataset with insignificant errors that uniquely identifies the recipient of the data set. In case such a dataset is leaked and appears in an unintended location, the entity who originally requested and leaked the dataset can be identified.
To embed a watermark into a dataset, a sequence of errors is created and then applied to the original data, i.e., for numerical values this is just adding value and error. A suspicious dataset is later on compared to the original dataset and extracting the error from the differences between the datasets leads to the original recipient.
- MyData Global in the EMWA Journal on Digital Watermarking: https://journal.emwa.org/the-data-economy/mydata-applying-human-centric-principles-to-health-data/
- Blogpost by NGI funded project MyPCH developing Digital Watermarking: https://www.ownyourdata.eu/en/digital-watermarking/