Method for implementing and using cryptographic material in at least one system component of an information technology system

Patent metadata

Field	Value
Publication number	US-12418414-B2
Application number	US-202218687532-A
Country	US
Kind code	B2
Filing date	Aug 2, 2022
Priority date	Aug 31, 2021
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A method for implementing and using cryptographic material in at least one system component of an information technology system for performing at least one operation involves describing a state of the system component by at least one variable is checked at least at a first time. The cryptographic material is supplemented with additional data describing possible states of system components. The cryptographic material is used by the system component when the additional data of the cryptographic material include comprise at least the state that the system component has at the first time. The additional data are formed by at least one condition, at least one role, and/or at least one target component identity.

First claim

The invention claimed is:

1. A method for implementing and using cryptographic material in at least one system component of an information technology system for performing at least one operation, the method comprising:
checking a state of the at least one system component as described by at least one variable at least at a first time;
forming additional data by at least one condition, at least a role, or at least one target component identity, wherein the additional data describe possible states of system components, and wherein all additional data comprised by the cryptographic material is cryptographically secured against being compromised;
supplementing the cryptographic material with the additional data; and
using the cryptographic material by the at least one system component when the additional data of the cryptographic material comprise at least the state that the system component has at the first time.

2. The method of claim 1 , wherein the all additional data comprised by the cryptographic material is cryptographically secured against being compromised using at least one digital signature or a symmetric integrity protection mechanism.

3. The method of claim 1 , wherein the cryptographic material comprises at least one target-component-specific role.

4. The method of claim 1 , wherein all conditions are defined by a creator external to the system component and evaluated by at least one evaluator executed in an environment of the system component, wherein the creator and the evaluator jointly determine which variables may be used by the creator in the definition.

5. The method of claim 1 , wherein the at least one variable has one of the following value ranges:
BOOLEAN;
INTEGER; or
STRING.

6. The method of claim 1 , wherein the at least one condition is defined target-component-specifically or operation-specifically.

7. The method of claim 6 , wherein the at least one different variable is used for a target-component-specific or operation-specific condition on a different target component or for a different operation.

8. The method of claim 7 , wherein an evaluator uses an evaluation function to check the at least one condition, wherein at least two different evaluators use a different evaluation function.

9. The method of claim 1 , wherein the at least one condition is defined in a machine-processable definition language, wherein an executable language that can be interpreted by an interpreter or one of the following formal logics is used:
propositional logic;
propositional logic with relations; or
propositional logic with relations and functions.

10. The method of claim 9 , wherein the at least one condition includes at least two conditions formulated in a definition language that differs from one another.

11. The method of claim 10 , wherein the cryptographic material comprises the at least two conditions and all of the at least two conditions must be met for the cryptographic material to be used by the system component.

12. The method of claim 6 , wherein if cryptographic material is to be used, a system component whose target-component-specific condition does not comprise a class of the corresponding system component, if an operation is to be performed by using the cryptographic material, which is not included in an operation-specific condition or if an evaluator cannot detect a variable required for checking a state, the evaluator returns the following answer by default for the respective condition:
TRUE;
FALSE; or
an answer appended to the cryptographic material as a standard answer.

13. The method of claim 11 , wherein at least two different actors are authorized to digitally sign the cryptographic material, wherein all actors authorized to sign receive the private keys respectively assigned to them with an associated individual leaf certificates and an associated certificate chain.

14. The method of claim 1 , wherein the information technology system Is a vehicle ecosystem.

Assignees

• Mercedes Benz Group Ag

Inventors

• Friesen Viktor
• Pavlovic Viktor

Classifications

• H04L9/3265

  using certificate chains, trees or paths; Hierarchical trust model · CPC title

• H04L9/3247

  involving digital signatures · CPC title

• H04L9/30

  Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy · CPC title

• H04L9/0877

  using additional device, e.g. trusted platform module [TPM], smartcard, USB or hardware security module [HSM] · CPC title

• H04L9/0897

  involving additional devices, e.g. trusted platform module [TPM], smartcard or USB · CPC title