Transmitting apparatus, communicating system

摘要

According to an aspect of the embodiment, there is provided a transmitting apparatus, including a data storage, a first key storage, a second key storage, an additional information generating unit, a first authenticator generating unit, a second authenticator generating unit, a third authenticator generating unit, and a packet transmitting unit.
a judging unit that judges the candidate is admitted as the second authenticator, when the candidate contains a common part of the first authenticator.a third authenticator generating unit generates a third authenticator based on a second authenticator that is a second authenticator candidate contains a common part of the first authenticator. The packet transmitting unit transmits a packet including the data and the third authenticator.

主权项

1. A transmitting apparatus comprising:
a first authenticator generating unit that generates a first authenticator based on data to be transmitting to a receiver and a first key, the first key authenticator having a common part; an additional information generating unit that generates first additional information; a candidate generating unit that generates a first candidate for a second authenticator, based on the data, a second key and the first additional information; a judging unit that judges the first candidate is admitted as the second authenticator, when the first candidate contains the common part of the first authenticator and; a third authenticator generating unit that generates a third authenticator, the third authenticator being generated using the second authenticator and a first part that is derived by removing the common part from the first authenticator; a transmitting unit that transmits the data and the third authenticator, wherein the additional information generating unit that generates second additional information when the first candidate contains no common part, and the candidate generating unit generates a second candidate for a second authenticator based on the data, the second key and the second additional information.