  We propose a new concept of secure list decoding, which is related to
bit-string commitment. While the conventional list decoding requires that the
list contains the transmitted message, secure list decoding requires the
following additional security conditions to work as a modification of
bit-string commitment. The first additional security condition is the
receiver's uncertainty for the transmitted message, which is stronger than the
impossibility of the correct decoding, even though the transmitted message is
contained in the list. The other additional security condition is the
impossibility for the sender to estimate another element of the decoded list
except for the transmitted message. The first condition is evaluated by the
equivocation rate. The asymptotic property is evaluated by three parameters,
the rates of the message and list sizes, and the equivocation rate. We derive
the capacity region of this problem. We show that the combination of hash
function and secure list decoding yields the conventional bit-string
commitment. Our results hold even when the input and output systems are general
probability spaces including continuous systems. When the input system is a
general probability space, we formulate the abilities of the honest sender and
the dishonest sender in a different way.
