(1) Field of the Invention
The present invention relates to a method of checking the authenticity of a document and to documents adapted for use in such method. More particularly the invention is concerned with a method of document authentication based on the use of magnetic ink and which can be accomplished by simple manipulation, using the human sense of touch as the discriminator. The invention may in principle be applied to the authentication of any kind of document upon which a region of magnetisable ink can be deposited or otherwise attached including, without limitation, banknotes, cheques, credit cards, passports, drivers licences, goods labels, tickets, vouchers, stamps, bonds, stock and share certificates, legal communications and any other such documents of intrinsic or extrinsic value which require protection from the risk of counterfeiting.
(2) Description of the Art
Many machine-readable anti-counterfeiting measures utilising a range of different technologies already exist for the protection of various documents, requiring the use of special external equipment to verify authenticity. Other measures, such as watermarks and holograms, can readily be perceived by the human sense of sight and their level of security depends on the degree of difficulty and/or cost to the potential counterfeiter of reproducing the identical features. One aim of the present invention is to provide an alternative form of anti-counterfeiting measure to be used as an adjunct to existing forms or in appropriate cases as a standalone measure which in a preferred embodiment requires no external equipment to verify authenticity (or in other embodiments requires the use of only a simple external device) so that authentication can be performed by any user aware of the existence of the technique, but whose presence need not be visually apparent to the uninformed, and the reproduction of which would present a technological barrier to the potential counterfeiter.