A current sensor includes: a current path; a semiconductor substrate; and a Hall element on the substrate. 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. Water is continuously recirculated through the target cavity to increase reliability. The protection sheet covering the magnetic transducer prevents the magnetic transducer from direct exposure.