Electrical computers and digital processing systems: support – Multiple computer communication using cryptography – Protection at a particular protocol layer
Reexamination Certificate
1998-01-05
2001-06-19
Swann, Tod (Department: 2132)
Electrical computers and digital processing systems: support
Multiple computer communication using cryptography
Protection at a particular protocol layer
Reexamination Certificate
active
06249872
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of computer systems. More specifically, the present invention relates to data security on computer systems.
2. Background Information
Existing methods of preventing unauthorized write access to non-volatile storage such as FLASH memory typically rely on “secret” access methods to a write enable circuit. These “secret” access methods to the write enable circuit can be reverse-engineered through the use of standard debugging hardware. Once reverse engineered, a person will be able to produce code that can write to the “protected” non-volatile storage at will. If the code is used in a malicious manner, it can be used to introduce viruses into the “protected” non-volatile storage or even destroy the content of the non-volatile storage.
Thus, it is desirable to have a more robust approach to preventing unauthorized access to non-volatile storage. As will be described in more detail below, the present invention achieves these and other desirable results.
BRIEF SUMMARY OF THE INVENTION
In one embodiment, the present invention relates to a computer implemented method for protecting a non-volatile storage element from unauthorized write accesses. This method initially involves the computer system entering into a mode of operation where an authentication process is performed. Next, the security circuit of the computer system is placed in a first predetermined state before leaving the mode of operation. Then, the state of the security circuit is checked in which the operations of the computer system are halted if the security circuit exists in a state other than the first predetermined state.
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Albrecht Mark
Wildgrube Frank L.
Blakely , Sokoloff, Taylor & Zafman LLP
Intel Corporation
Smithers Matthew
Swann Tod
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