Data processing device for railed vehicle control
There is provided a data processing device disposed in a carriage of a railed vehicle. The data processing device includes an operation processor. The operation processor (a) generates an initial authentication value for carriage by computing unique identification information of electronic devices disposed in the carriage by using a hash algorithm, (b) transmits an encryption key and a hash key to the electronic devices; (c) receive, from an i-th electronic device, i-th state data including i-th state information and an i-th device authentication value, and authenticate the i-th state data where “i” is an integer from 1 to n; (d) generates carriage data using state data authenticated in (c); and (e) generates a carriage authentication value based on device identification information obtained from the state data, and authenticates the carriage data by comparing the carriage authentication value with the initial authentication value for carriage.
1 . A data processing device disposed in a carriage of a railed vehicle, the data processing device comprising:
an operation processor configured to perform:
(a) generating an initial authentication value for the carriage by computing first unique identification information to n-th unique identification information of a first electronic device to an n-th electronic device that are disposed in the carriage by using a predetermined hash algorithm that takes as input the first unique identification information to the n-th unique identification information, wherein “n” is an integer equal to or greater than 2;
(b) transmitting an encryption key and a hash key to the first electronic device to the n-th electronic device;
(c) receiving, from the first electronic device to the n-th electronic device, first state data including first state information and a first device authentication value to n-th state data including n-th state information and an n-th device authentication value, and authenticating the first state data to the n-th state data;
(d) generating carriage data using the first state data to the n-th state data authenticated in (c); and
(e) generating a carriage authentication value based on first device identification information to n-th device identification information obtained from the first state data to the n-th state data, and authenticating the carriage data by comparing the carriage authentication value with the initial authentication value for the carriage,
wherein i-th state data including i-th state information and an i-th device authentication value is received from an i-th electronic device among the first electronic device to the n-th electronic device, and is encrypted by the encryption key and,
wherein, in (c), an authentication value is generated by computing at least a portion of the i-th state information by using the hash key and a predetermined first message authentication code (MAC) generation algorithm that takes as input at least the portion of the i-th state information, and the i-th state data is authenticated by comparing the generated authentication value with the i-th device authentication value included in the i-th state data.
2 . The data processing device of claim 1 , wherein
the first unique identification information to the n-th unique identification information are received from the first electronic device to the n-th electronic device, respectively, or are received from a predetermined external device.
3 . The data processing device of claim 1 , wherein (a) is performed prior to putting the railed vehicle into service, or (a) is performed when each of the first electronic device to the n-th electronic device is mounted and powered on in the carriage.
4 . The data processing device of claim 1 , wherein the encryption key and the hash key are received from a gateway device disposed in the railed vehicle.
5 . The data processing device of claim 4 , wherein the encryption key and the hash key are generated by the gateway device using unique identification information of the railed vehicle and a multicast key received from a predetermined external device.
6 . The data processing device of claim 1 , wherein at least the portion of the i-th state information is encrypted using a stream cipher method.
7 . The data processing device of claim 1 , wherein the carriage data has a format according to a train control and monitoring system (TCMS) protocol.
8 . The data processing device of claim 1 , wherein the i-th state data includes first partitioned state data to m-th partitioned state data wherein “m” is an integer equal to or greater than 2,
the i-th device authentication value includes a first MAC tag to a m-th MAC tag,
j-th partitioned state data among the first partitioned state data to the m-th partitioned state data includes at least j-th serial number information, a j-th MAC chaining value, j-th payload information, and a j-th MAC tag wherein “j” is an integer from 1 to m, and
wherein, in (c), another authentication value is generated by computing at least the j-th MAC chaining value and the j-th payload information by using the hash key and the predetermined first MAC generation algorithm that takes as input at least the j-th MAC chaining value and the j-th payload information, and the j-th partitioned state data is authenticated by comparing the j-th MAC tag with the other authentication value.
9 . The data processing device of claim 8 , wherein if “j” is equal to 1, the j-th MAC chaining value is a predetermined initial value, and
if “j” is not equal to 1, the j-th MAC chaining value is generated based on (j−1)-th MAC chaining value.
10 . The data processing device of claim 8 , wherein if “j” is equal to 1, the j-th MAC chaining value is generated by computing i-th unique identification information by using the hash key and the predetermined first MAC generation algorithm that takes as input the i-th unique identification information, and
if “j” is not equal to 1, the j-th MAC chaining value is generated by computing the (j−1)-th MAC chaining value by using the hash key and the predetermined first MAC generation algorithm that takes as input the (j−1)-th MAC chaining value.
11 . The data processing device of claim 8 , wherein if “j” is not equal to 1, a (j−1)-th MAC tag is used for the j-th MAC chaining value.
12 . The data processing device of claim 8 , wherein, in (c), the j-th payload information is decrypted using the encryption key and a stream encryption method when the j-th partitioned state data is authenticated.
13 . The data processing device of claim 8 , wherein the j-th payload information includes a j-th payload and a j-th padding that are in encrypted form,
the j-th partitioned state data further includes j-th length information that includes a length of the j-th payload and a length of the j-th padding, and
the authentication value is generated by computing at least the j-th MAC chaining value, the j-th length information, and the j-th payload information by using the hash key and the predetermined first MAC generation algorithm that takes as input at least the j-th MAC chaining value, the j-th length information, and the j-th payload information.
14 . The data processing device of claim 1 , wherein the carriage authentication value is generated by computing the first device identification information to the n-th device identification information by using the predetermined hash algorithm that takes as input the first device identification information to the n-th device identification information, and
wherein, in (e), the carriage data is authenticated if the carriage authentication value is the same as the initial authentication value for the carriage.
15 . The data processing device of claim 1 , wherein the operation processor is further configured to perform:
(f) transmitting the carriage data that is generated in (d) and authenticated in (e) to a gateway device disposed in the railed vehicle.
16 . The data processing device of claim 15 , wherein, in (f),
the carriage data is transformed into first partitioned carriage data to p-th partitioned carriage data using the encryption key and the hash key wherein “p” is an integer equal to or greater than 2, and
the first partitioned carriage data to the p-th partitioned carriage data are transmitted to the gateway device,
wherein k-th partitioned carriage data among the first partitioned carriage data to the p-th partitioned carriage data includes at least k-th serial number information, a k-th MAC chaining value, k-th payload information, and a k-th MAC tag wherein “k” is an integer from 1 to p,
if “k” is equal to 1, the k-th MAC chaining value is a predetermined initial value, and if “k” is not equal to 1, the k-th MAC chaining value is generated based on (k−1)-th MAC chaining value,
the k-th MAC tag is generated by computing at least the k-th MAC chaining value and the k-th payload information by using the hash key and a predetermined second MAC generation algorithm that takes as input at least the k-th MAC chaining value and the k-th payload information, and
the k-th payload information is encrypted using the encryption key.
17 . The data processing device of claim 16 , wherein the k-th payload information is encrypted using a stream cipher method.
18 . The data processing device of claim 16 , wherein the predetermined initial value is generated by computing the initial authentication value for the carriage by using the hash key and the predetermined second MAC generation algorithm that takes as input the initial authentication value, and
if “k” is not equal to 1, the k-th MAC chaining value is generated by computing the (k−1)-th MAC chaining value by using the hash key and the predetermined second MAC generation algorithm that takes as input the (k−1)-th MAC chaining value.
19 . The data processing device of claim 16 , wherein if “k” is not equal to 1, (k−1)-th MAC tag is used for the k-th MAC chaining value.
20 . The data processing device of claim 16 , wherein the k-th payload information includes a k-th payload and a k-th padding that are in encrypted form,
the k-th partitioned carriage data further includes k-th length information that includes a length of the k-th payload and a length of the k-th padding, and
the k-th MAC tag is generated by computing the k-th MAC chaining value, the k-th length information, and the k-th payload information by using the hash key and the predetermined second MAC generation algorithm that takes as input the k-th MAC chaining value, the k-th length information, and the k-th payload information.