Volatile key apparatus for safeguarding confidential data stored in a computer system memory

• US 6,292,899 B1
• Filed: 09/23/1998
• Issued: 09/18/2001
• Est. Priority Date: 09/23/1998
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Randall C. McBride
• Inventors: McBride, Randall C.
• Primary Examiner(s): Swann, Tod
• Assistant Examiner(s): Callahan, Paul E.
• Application Number:
  US09/159,069
• Time in Patent Office: 1,091 Days
• Field of Search: 713/194, 713/185, 713/200, 713/165, 713/193, 713/201, 380/281, 380/284
• US Class Current: 726/22
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2143 Clearing memory, e.g. to prevent the data from being stolen

Abstract

The data security system uses a volatile key apparatus to create and manage a master file, comprising a single encrypted file that is stored on the hard drive of the computer system. The master file contains all of the passwords, cryptokeys and security codes that are used by conventional security programs and apparatus resident on the computer system to safeguard the confidential data that is contained in the memory of the computer system. The master key that is used to encrypt and decrypt this master file is stored in the volatile key apparatus, which is a piece of hardware located in the personal computer and directly connected to the system bus. When a violation of the system security procedures is detected, the master key is erased from the volatile key apparatus, thereby preventing access to the encrypted information that is stored on the hard drive. The encryption protected data can still be retrieved from the hard drive by the authorized user reinstalling the master key in the volatile key apparatus, thereby enabling decryption of the encrypted passwords, cryptokeys and security codes that are stored in the master file. The conventional security programs and apparatus resident on the computer system can then use the contents of the master file to retrieve the encrypted data from the memory.

Claims

1. A data security system resident in a computer system for preventing unauthorized access to at least one encrypted data file stored in a memory of said computer system, comprising:

means for encrypting a private key associated with an encrypted data file and that is used to decrypt said encrypted data file, using a master key;

means for storing said encrypted private key;

volatile memory means for storing said master key;

means, responsive to a request to decrypt said encrypted data file, for generating said private key from said encrypted private key using said master key;

means for detecting a security violation; and

means, responsive to a detected security violation, for automatically erasing said master key from said volatile memory means.

2. The data security system of claim 1 wherein said means for detecting a security violation comprises:

means for detecting an attempt at unauthorized access to said encrypted data file.

3. The data security system of claim 1 wherein said means for detecting a security violation comprises:

means for detecting an anomaly in said means for encrypting.

4. The data security system of claim 1 wherein said means for generating comprises:

means for decrypting said private key from said encrypted private key;

key control means for regulating generation of said private key;

security manager means, responsive to said request to decrypt said encrypted data file, for switching control of a processor in said computer system to said key control means; and

wherein said key control means is responsive to receipt of control of said processor for transmitting said master key to said means for decrypting to produce said private key.

5. The data security system of claim 4 wherein said key control means is responsive to generation of said private key for erasing said master key from said processor.

6. The data security system of claim 1 further comprising:

means, responsive to said means for erasing having removed said master key from said volatile memory means, for enabling an authorized user to rewrite said master key into said volatile memory means.

7. A method of operating a data security system that is resident in a computer system to prevent unauthorized access to at least one encrypted data file stored in a memory of said computer system, comprising the steps of:

encrypting a private key associated with an encrypted data file and that is used to decrypt said encrypted data file, using a master key;

storing said encrypted private key in a master file memory;

storing said master key in a volatile memory;

generating, in response to a request to decrypt said encrypted data file, said private key from said encrypted private key using said master key;

detecting a security violation; and

erasing, in response to a detected security violation, said master key from said volatile memory.

8. The method of operating a data security system of claim 7 wherein said step of detecting a security violation comprises:

detecting an attempt at unauthorized access to said encrypted data file.

9. The method of operating a data security system of claim 7 wherein said step of detecting a security violation comprises:

detecting an anomaly in said step of encrypting.

10. The method of operating a data security system of claim 7 wherein said step of generating comprises:

decrypting in a cipher engine said private key from said encrypted private key;

regulating generation of said private key;

switching control of a processor in said computer system to said key control means in response to said request to decrypt said encrypted data file; and

wherein said step of regulating generation is responsive to receipt of control of said processor for transmitting said master key to said cipher engine to produce said private key.

11. The method of operating a data security system of claim 10 wherein said step of regulating generation is responsive to generation of said private key for erasing said master key from said processor.

12. The method of operating a data security system of claim 7 further comprising the step of:

enabling, in response to said step of erasing having removed said master key from said volatile memory, an authorized user to rewrite said master key into said volatile memory.

13. A data security system resident in a computer system for preventing unauthorized access to encrypted data file stored in a memory of said computer system, comprising:

cipher engine means for encrypting a data file using a private key that is also capable of decrypting said data file;

means for storing said encrypted data file;

means for encrypting said private key using a master key;

means for storing said encrypted private key in a master file memory;

volatile memory means for storing said master key;

means, responsive to a request to decrypt said encrypted data file, for generating said private key from said encrypted private key stored in said master file memory using said master key;

means for detecting a security violation; and

means, responsive to a detected security violation, for erasing said master key from said volatile memory means.

14. The data security system of claim 13 wherein said means for generating comprises:

means for decrypting said private key from said encrypted private key;

key control means for regulating generation of said private key;

security manager means, responsive to said request to decrypt said encrypted data file, for switching control of a processor in said computer system to said key control means; and

wherein said key control means is responsive to receipt of control of said processor for transmitting said master key to said means for decrypting to produce said private key.

15. The data security system of claim 14 wherein said key control means is responsive to generation of said private key for erasing said master key from said processor.

16. A method of operating a data security system that is resident in a computer system for preventing unauthorized access to encrypted data file stored in a memory of said computer system, comprising the steps of:

encrypting, in a cipher engine, a data file using a private key that is also capable of decrypting said data file;

storing said encrypted data file;

encrypting said private key using a master key;

storing said encrypted private key in a master file memory;

storing said master key in a volatile memory;

generating, in response to a request to decrypt said encrypted data file, said private key from said encrypted private key stored in said master file memory using said master key;

detecting a security violation; and

erasing, in response to a detected security violation, said master key from said volatile memory.

17. The method of operating a data security system of claim 16 wherein said step of generating comprises:

decrypting said private key from said encrypted private key;

regulating generation of said private key;

switching, in response to said request to decrypt said encrypted data file, control of a processor in said computer system to said step of regulating generation; and

wherein said step of regulating generation is responsive to receipt of control of said processor for transmitting said master key to said cipher engine to produce said private key.

18. The method of operating a data security system of claim 17 wherein said step of regulating generation is responsive to generation of said private key for erasing said master key from said processor.