Secured data storage devices

• US 5,150,407 A
• Filed: 12/16/1991
• Issued: 09/22/1992
• Est. Priority Date: 12/16/1991
• Status: Expired due to Fees

• Current Assignee: Steve S.C. Chan
• Original Assignee: Steve S.C. Chan
• Inventors: Chan, Steve S. C.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): CAIN, DAVID C
• Application Number:
  US07/807,976
• Time in Patent Office: 281 Days
• Field of Search: 380/3, 380/4, 380/23, 380/25
• US Class Current: 713/178
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/40975 using encryption therefor
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system

Abstract

A device for storing user data and a value representative of the time of storage is disclosed, which includes physically separating portions of an encryption key, combining a time stamp with user data, and using the restored encryption key to encrypt and decrypt the stamped user data.

Claims

1. A device for storing user data and the time of storage of the user data comprising:

storage means for storing data, said storage means having a first storage area for storing a first portion of a first key;

clock means for keeping time continuously;

means for generating a value representative the time indicated by said clock means;

first key storage means for storing a second portion of said first key, said first key storage means being physically separated from said storage means;

means for generating a set of combined data by combining the user data and said value representative of the time;

means for generating a set of encoded data in response to said set of combined data as a function of said first portion and said second portion of said first key;

encoded data storage means for storing said set of encoded data in said storage means in reponse to a first user command;

means for retrieving said set of encoded data from said storage means in response to a second user command; and

means for decoding said encoded data as function of said first portion and said second portion of said first key.

2. The device of claim 1 wherein said encoded data storage means further includes means for distributing said set of encoded data to different storage locations in said storage means.

3. The device of claim 2 wherein said storage means further comprises a second storage area for storing a first portion of a second key and wherein said means of distribution futher comprises second key storage means for storing a second portion of said second key, said second key storage means being separated from said storage means, said means for distributing being a function of said first and said second portions of said second key.

4. The device of claim 1 wherein said means for generating the value representative of the time further comprising:

means for allowing a user to perform an adjustment to the time and data; and

means for limiting said adjustment to below a predetermined maximum deviation.

5. The device of claim 4 wherein said predetermined maximum deviation being a function of a maximum error rate of said clock means.

6. The device of claim 1 further comprising a secured enclosure for housing said means for generating the value representative of said time and data, said first key storage means, said means of generating said set of combined data, and said means of generating said set of encoded data.

7. The device of claim 1 wherein said first key storage means and said means of generating said set of encoded data are stored in a digital device which denies electrical access by external means.

8. The device of claim 1 wherein said means for generating said set of encoded data being further a function of the time for formatting said storage means.

9. The device of claim 1 wherein said storage medium is organized into logical sector numbers and wherein said means for generating said set of encoded data is further a function of said logical sector numbers.

10. The device of claim 2 wherein said means for distributing being further a function of the time for formatting said storage means.

11. The device of claim 2 wherein said storage medium is organized into logical sector numbers and wherein said means for distributing is further a function of said logical sector numbers.