There is presented a method and apparatus for incorporating digital signature to within a document for paper-less office. The method comprises generating the document to be signed on a computer and transferring it and displaying it on a device for incorporating digital signature wherein the device comprises a screen, signature means such as electronic pen or fingerprint capturing device, and et least one smart card reader. Then, the document is being digitally signed. The digitally signed document is being encrypted and transferred to the computer so as to prevent restoration of the digital signature. From the customer side, the procedure is based on “what you see is what you sign”.