A source coding problem for sources with additional outputs to keep secret from the receiver or wiretappers (Corresp.)

A new source coding problem is considered for a one-way communication system with correlated source outputs . One of the source outputs, i.e., , must be transmitted to the receiver within a prescribed distortion tolerance as in ordinary source coding. On the other hand, the other source output, i.e., , has to be kept as secret as possible from the receiver or wiretappers. For this case the equivocation-distortion function and the rate-distortion-equivocation function are defined and evaluated. The former is the maximum achievable equivocation of under the distortion tolerance for , and the latter is the minimum rate necessary to attain both the equivocation tolerance for and the distortion tolerance for . Some examples are included.