Method and device for checking an incoming secured, encrypted message
A method for checking an incoming message. In the method, based on the message authentication code, an authentication of the useful data is performed by a hardware security module and the hardware security module is subjected to a function check.
1. A method for checking an incoming message that includes useful data and a message authentication code, the method comprising the following steps:
performing, by a hardware security module, an authentication of the useful data based on the message authentication code;
performing a function check on the hardware security module, wherein:
the authentication and function check include a comparison of the message authentication code;
for the function check, an input for the comparison is taken from a lookup table;
for the comparison, a computational message authentication code is ascertained and a comparison of the computational message authentication code to the input is made; and
a result of the comparison is output for the authentication or the function check;
utilizing the useful data when the result indicates satisfactorily passing of the comparison; and
discarding the useful data when the result indicates satisfactorily not passing of the comparison.
2. The method as recited in claim 1 , wherein:
the authentication takes place on a functional level; and
the function check take place via continuous monitoring of the hardware security module on a monitoring level.
3. The method as recited in claim 2 , wherein:
the functional level satisfies general quality standards; and
the monitoring level satisfies safety requirements according to ISO (International Organization for Standardization) 26262.
4. The method as recited in claim 1 , wherein: for the function check, the result is evaluated based on the lookup table.
5. The method as recited in claim 1 , wherein the message is received via a vehicle network.
6. A non-transitory machine-readable memory medium on which is stored a computer program for checking an incoming message that includes useful data and a message authentication code, the computer program, when executed by a computer, causing the computer to perform the following steps:
performing, by a hardware security module, an authentication of the useful data based on the message authentication code;
performing a function check on the hardware security module, wherein:
the authentication and function check include a comparison of the message authentication code;
for the function check, an input for the comparison is taken from a lookup table;
for the comparison, a computational message authentication code is ascertained and a comparison of the computational message authentication code to the input is made; and
a result of the comparison is output for the authentication or the function check
utilizing the useful data when the result indicates satisfactorily passing of the comparison; and
discarding the useful data when the result indicates satisfactorily not passing of the comparison.
7. A device configured to check an incoming message that includes useful data and a message authentication code, the device including a hardware security module and configured to:
perform, using the hardware security module, an authentication of the useful data based on the message authentication code;
perform a function check on the hardware security module, wherein:
the authentication and function check include a comparison of the message authentication code;
for the function check, an input for the comparison is taken from a lookup table;
for the comparison, a computational message authentication code is ascertained and a comparison of the computational message authentication code to the input is made; and
a result of the comparison is output for the authentication or the function check;
utilize the useful data when the result indicates satisfactorily passing of the comparison; and
discard the useful data when the result indicates satisfactorily not passing of the comparison.