Cryptography – Key management – Having particular key generator
Patent
1995-05-31
1998-02-24
Louis-Jacques, Jacques
Cryptography
Key management
Having particular key generator
395490, 395479, 395410, 380 4, 380 25, G06F 300, H04L 900
Patent
active
057218773
ABSTRACT:
A method and apparatus for limiting access to a nonvolatile memory device by inserting access limiting circuitry between CPU generated read and write command signals being sent to the nonvolatile memory device and the nonvolatile memory device itself such that write commands can be received and executed by the nonvolatile memory device only when the CPU is in a System Management Mode, and such that read commands for protected addresses can be received and executed by the nonvolatile memory device only when the CPU is in the System Management Mode, but is still able receive and executed read commands for non-protected addresses regardless of the mode of the CPU. This feature can also be provided for the write command. The access limiting circuitry is therefore capable of preventing a virus program, or a malfunctioning operating system, from undesirably altering data in the nonvolatile memory device since the operating system is preempted when the CPU is in the System Management Mode.
REFERENCES:
patent: 4519032 (1985-05-01), Mendell
patent: 4521852 (1985-06-01), Guttag
patent: 4521853 (1985-06-01), Guttag
patent: 4590552 (1986-05-01), Guttag et al.
patent: 4959860 (1990-09-01), Watter et al.
patent: 5027317 (1991-06-01), Pepera et al.
patent: 5084843 (1992-01-01), Mitsuishi et al.
patent: 5206938 (1993-04-01), Fujioka
patent: 5371793 (1994-12-01), Kimura
patent: 5392290 (1995-02-01), Brown et al.
patent: 5406508 (1995-04-01), Hayashibara
patent: 5469557 (1995-11-01), Salt et al.
patent: 5475829 (1995-12-01), Thome
patent: 5511204 (1996-04-01), Crump et al.
patent: 5586286 (1996-12-01), Santeler et al.
patent: 5586301 (1996-12-01), Fisherman et al.
patent: 5596741 (1997-01-01), Thome
patent: 5623673 (1997-04-01), Gephardt et al.
VLSI VL82C591 Preliminary Device Functional Specification -Specifically Section 5.4.3.3. Nov. 1993.
Aiyar Sanjay
Heflinger Kenneth A.
AST Research Inc.
Louis-Jacques Jacques
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