Abstract: This invention describes a process for improvements in security for personal identification documents, particularly for machine-readable passports. An image of a personal identifier of a holder of the document is stored as a highly-compressed digital image in a magnetic medium dispersed invisibly within the material of a visible print forming part of the document or within the body of the document itself. The document is then scanned magnetically at the place where identification is required and the stored image decompressed and displayed. This provides confirmation that the holder of the document is the person shown on the visible image, that the document has not been tampered with, and by checking the image code against a database, that the document was originated by the proper authority.