Abstract: There are disclosed in the present application, devices and methods for providing identification of a client by his ability to select a correct set of digits from a multiplicity of them on any one of a plurality of grids each with a different order and arrangement of digits on a suitable surface. The client easily establishes his identity by selecting the correct digits from any randomly selected grid at the subscriber location by obtaining in advance, a password from which he determines the correct digits by their positions in all the grids. The accuracy of the client's answer is checked against a register listing, for each client, an independent identification number, and his password. The register also contains a list of correct digits or codes and the grid number for which each code is the appropriate answer.

Abstract: There are disclosed in the present application devices and systems for providing proof of identity of a client by the client's ability to select predetermined digits from a multiplicity of digits randomly arranged in a grid of a plurality of sets of digits in which each set consists of several digits. A multiplicity of grids is provided each with a different order and arrangement of digits on a suitable surface so that the client, in order to establish his identity, is required to select the digits from one of the large number of grids. The manner in which the client selects his identifying digits is by being given in advance a positional code from which he determines the correct digits by their locations in the grid. The accuracy of the client's answer is checked against a register listing the client's social security number and an identification of the specific grids together with required identification numbers relating to the specific grids.