Abstract: The method verifies the integrity and authenticity of a page received by the browser client (10) provided in a terminal station (E) of a user client. The method uses two program modules: a signature program module (22): an application executed by the Web server (21) provided in an institution (I) and which intercepts the pages to be sent to the user client and, in case the page is configured as a page to be signed, said module performs the signature with an identifier code and includes, at the end thereof, a tag, whose content is the signature. a verification program module (12): an application executed in the environment of the user client which monitors the pages accessed by the browser client (10). Upon finding a page to be validated, it verifies the presence of the signature tag and validates whether the signature is correct, that is, whether it has really been executed by the correct server and whether the identifier code (HTML) has not been modified.