An information processing apparatus that enables management of copyrighted
content to which identification information is not added. An arithmetical
unit computes a hash value based on data from a portion of the content
data recorded in a mini-disk (MD), and transmits the value from an
input/output unit to a personal computer. Based on the hash value, the
personal computer identifies the content recorded in the MD, and performs
management procedures based on the display information of check-in and
checkout of the content. The information processing apparatus can also be
applied to personal computers.