Patent ID: 8464070
Filing Date: 2013-06-11
Classification: H04L

Abstract:
1. An apparatus for transmitting data, the apparatus comprising: an authentication code generator configured to generate a message authentication code using an i-th message and an encryption key assigned to the i-th message, wherein i denotes an integer; an encryption unit configured to generate a first cryptogram by encrypting the message authentication code using first encryption keys from an encryption key assigned to an (i−1)-th message to another encryption key assigned to an (i−d+1)-th message, and generate a second cryptogram by encrypting the message authentication code using second encryption keys from the encryption key assigned to the (i−1)-th message to a different encryption key assigned to an (i-d)-th message, wherein d denotes an integer greater than or equal to 1; and a transmitter configured to transmit the i-th message, the first cryptogram, and the second cryptogram, which are used to determine whether the i-th message is valid.