Systems and methods and computer programs for verifying the authenticity
and integrity of hyperlink addresses and files that are accessible by
means of these hyperlink addresses. A system and a method are disclosed
for authenticating a file such as an HTML document hyperlinked to a
graphic object such as a digital image or to a graphic icon. The
hyperlink network address (e.g., the URL of the hyperlink on the
Internet) is encoded on a first portion of the graphic object. Checking
information such as a MAC digital signature and the hyperlinked file are
encoded into a second portion of the same graphic object. In accordance
with another aspect of the invention, a system and a method are disclosed
for verifying the authenticity and integrity of a hyperlink and a file
when this hyperlink is activated.