Abstract: A method of producing an invisible electronic signature insusceptible to human damages or anamorphous compression. This new electronic signature technology uses the pixel contrast, error propagation, channel coding and cross encoding techniques. Once the electronic signature is embedded, it can still be recovered and recognized even after the generated image is damaged by human errors or anamorphous compression.

Abstract: Content is authenticated by generating signature certificates for content that has been successfully watermark screened. When a request is received for importation of content into a secured domain, a search is made in a signature certificates cache for a signature certificate associated with that requested content. If an identified signature certificate authenticates the requested content, the content is imported into the secured domain. If no signature certificate is identified, the content is watermark screened. If the content successfully passes the watermark screening process, a new signature certificate is then added to the signature certificate cache.