To provide a communication system and a communication terminal for performing multi-hop transmissions securely with a small amount of delay.
A communication device includes an authentication key managing means of managing an authentication key; a time-varying parameter managing means of managing a time change parameter for verifying the freshness of a secure communication frame; a reception authentication history managing means of managing reception authentication history information of a secure communication frame; and a communication frame authenticating means of performing authentication processings on the received communication frame by the authentication key and the time change parameter. The communication frame authenticating means determines that a secure communication frame that has succeeded in authentication is a new and valid communication frame, when the time-varying parameter utilized for security conversion of a secure communication frame is determined as being newer than a past value by a prescribed value, in reference to the time-varying parameter managed by the time change parameter managing means; and the secure communication frame is determined as not having been received in the past by the reception authentication history managing means.
FUKUI KIYOSHI
NAKAJIMA JUN
| JP2008263421A | 2008-10-30 | |||
| JP2008131083A | 2008-06-05 | |||
| JP2006295739A | 2006-10-26 |
| WO2009130917A1 | 2009-10-29 |
Yusuke Wakabayashi