The new technology is based on previous bar code research and incorporates a procedure for the concealment of the bar code as a latent image on the security instrument. This new security system has been developed in two steps. The first part involves a special software package designed to print the visible bar code directly onto the document. Included in the bar code are the interference code and independent series check sum. The second part involves the total covering of the visible bar code with a special ink, resulting in a latent bar code on the document. A decoding device allows the user or the document examiner to scan the document's latent security bar code and immediately read the contents of the bar code on an accompanying monitor. The latent bar code approach retains many of the functions used when reading visible bar code information, including the storage and retrieval of information and the simultaneous reading and identification of information for verification purposes. Figures and 25 reference notes