Security method for protecting electronically stored data
First Claim
1. In an electronic control module for an internal combustion engine comprising a microprocessor, a ROM containing a controller program and a data security program and a non-volatile memory having data protected addresses including a password address, means for reading and writing protected data to the data protected addresses, and communications means for receiving and sending messages;
- the method of maintaining secrecy of protected data comprising the steps of;
activating security by writing a password into the data protected password address;
when security is activated, rejecting messages requesting protected data;
deactivating security by supplying a correct password;
complying with requests for reading or writing protected data when security is deactivated;
entering a command for access to protected addresses irrespective of the state of security to recover said electronic control module without use of a password; and
responding to the command by erasing the protected data and then complying with the command, thereby ensuring the secrecy of the protected data.
2 Assignments
0 Petitions
Accused Products
Abstract
A microprocessor based electronic control module with an EEPROM for storing protected data allows the data to be used internally, and allows non-sensitive data to be accessed by external communication tools, but prohibits access to the protected data unless a password is first entered. Then the data may be read from memory and the data or the password may then be changed. For a given model of control module, an ID number is assigned to the password and stored in the module, and can be read to allow the user to find the corresponding password on a secure list available only to authorized personnel. When a password can not be found and it is necessary to change the protected data, the unit can be recovered by a recover procedure wherein the secure data is first erased and then the security is deactivated to grant free access.
64 Citations
9 Claims
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1. In an electronic control module for an internal combustion engine comprising a microprocessor, a ROM containing a controller program and a data security program and a non-volatile memory having data protected addresses including a password address, means for reading and writing protected data to the data protected addresses, and communications means for receiving and sending messages;
- the method of maintaining secrecy of protected data comprising the steps of;
activating security by writing a password into the data protected password address; when security is activated, rejecting messages requesting protected data; deactivating security by supplying a correct password; complying with requests for reading or writing protected data when security is deactivated; entering a command for access to protected addresses irrespective of the state of security to recover said electronic control module without use of a password; and responding to the command by erasing the protected data and then complying with the command, thereby ensuring the secrecy of the protected data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- the method of maintaining secrecy of protected data comprising the steps of;
Specification