Tamper-resistant control unit
View Patent ↗A control unit is described for technical installations, devices and/or machines having a microprocessor, a programmable memory and a housing enclosing the microprocessor and programmable memory. Data lines lead out of the housing for connection with an external device for writing data to the programmable memory. The control unit is enclosed in the housing such that the operability of the control unit is at least partly destroyed when the housing is opened. The control unit furthermore has a check device that checks for authorization a write access by which data are written to the programmable memory over the data line, and causes the data to be written to the programmable memory only in case of a successful check of authorization.
1. A machine control unit operatively connected to a technical machine for controlling said technical machine, comprising:
a microprocessor;
a programmable memory including a control program required by the microprocessor;
a housing encapsulating at least the programmable memory;
at least one data line leading out of the housing for connection with an external device for writing data, reading data, or a combination thereof, to or from the programmable memory; and
an authorization check device to check for authorization of a write access, read access, or a combination thereof, by which data are written to the programmable memory or read therefrom over the data line, and to cause the data to be read from/written to the programmable memory only in case of a successful check of authorization, whereas said data to be read from/written to the programmable memory relate to changes or extensions in behavior of the machine control unit;
wherein the behavior of the machine control unit controls operation of said technical machine,
wherein the machine control unit is encapsulated in the housing such that the operability of the machine control unit is at least partly irreversibly destroyed, by destruction of essential hardware components or erasure of software parts important for operability of the machine control unit, when the housing is opened, and
wherein the authorization check device includes means for establishing a connection to a third authority and causes the data to be read from/written to the programmable memory only when read/write access has been released by said third authority.
2. A machine control unit according to claim 1 , characterized in that the authorization check device comprises a memory with a secret check word and a comparing device for comparing with said check word for an authorization check a keyword transferred to the control device over a data line before a write access.
3. A machine control unit according to claim 1 , characterized in that the authorization check device comprises means for carrying out a challenge-response method for an authorization check.
4. A machine control unit according to claim 1 , characterized in that the authorization check device comprises means for encryption of data, decryption of data, or a combination thereof.
5. A machine control unit according to claim 1 , characterized in that the authorization check device comprises means for checking a digital signature of the control related data transferred over the data line.
6. A machine control unit according to claim 1 , characterized in that the device control unit is encapsulated in the housing such that memory areas containing at least one of a secret check word, secret key and secret encryption algorithm are erased, destroyed, or both, when the housing is opened.
7. A method for controlling an automobile engine, comprising providing a machine control unit according to claim 1 , operatively connected to an automobile engine, for controlling said automobile engine.