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\{XY\}. One of the source outputs, i.e.,\{X\}, 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.,\{Y\}, has to be kept as secret as possible from the receiver or wiretappers. For this case the equivocation-distortion functionΓ (d)and the rate-distortion-equivocation functionR (d,e)are defined and evaluated. The former is the maximum achievable equivocation of\{Y\}under the distortion tolerancedfor\{X\}, and the latter is the minimum rate necessary to attain both the equivocation toleranceefor\{Y\}and the distortion tolerancedfor\{X\}. Some examples are included.