Digital Bazaar Adobe Systems When using a hyperlink to fetch a resource from the Internet, it is often useful to know if the resource has changed since the data was published. Cryptographic hashes, such as SHA-256, are often used to determine if published data has changed in unexpected ways. Due to the nature of most hyperlinks, the cryptographic hash is often published separately from the link itself. This specification describes a data model and serialization formats for expressing cryptographically protected hyperlinks. The mechanisms described in the document enables a system to publish a hyperlink in a way that empowers a consuming application to determine if the resource associated with the hyperlink has changed in unexpected ways.