Error correction in a reversed communications scenario

The identity of a certain part X is commonly established by receiving from it an n-bit signal desirably known only to X and the receiver. This demonstrates a case where the purpose of transmitting n bits is not for increasing the knowledge of the receiver by n units of information, but for proving to the receiver that the transmitter has that information. This demonstrates a case of a `reversed¿¿ communications scenario. Various considerations regarding the implementation of error-correcting codes in such schemes are discussed in the paper.