Method and means to limit access to computer systems

• US 5,233,658 A
• Filed: 04/04/1991
• Issued: 08/03/1993
• Est. Priority Date: 05/09/1990
• Status: Expired due to Term

• Current Assignee: James S. Bianco, James T. Madsen, John S. Fahy, Michael Ceppetelli
• Original Assignee: James S. Bianco, James T. Madsen, John S. Fahy, Michael Ceppetelli
• Inventors: Madsen, James T., Ceppetelli, Michael, Fahy, John S., Bianco, James S.
• Primary Examiner(s): CAIN, DAVID C
• Application Number:
  US07/680,429
• Time in Patent Office: 852 Days
• Field of Search: 235/449, 235/450, 70/276, 382/7, 380/25, 380/4
• US Class Current: 713/185
• CPC Class Codes: G06F 21/34 involving the use of external additional devices, e.g. dongles or smart cards
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof
• CPC Class Codes: G06K 19/12 the marking being sensed by magnetic means
• CPC Class Codes: G06K 7/087 flux-sensitive, e.g. magnetic, detectors G06K7/10336 takes precedence
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/086 by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/12 Card verification
• CPC Class Codes: Y10T 70/7057 Permanent magnet

Abstract

In a preferred embodiment, a method of limiting access to computer systems which method includes scrambling identification card information with time information so that the resulting code can be used for only a limited period of time, thus preventing unauthorized persons from using the code at a later time. In another aspect of the invention, one or more μ-metal shields are embedded in an identification card, thus identifying the card as being valid and also providing means to indicate when a valid card is being removed from a card reader.

Claims

1. A method of terminating access to a computer system, comprising:

(a) providing a mu-metal shield at a selected location in an identification card;

(b) providing a slot card insertion reader having disposed therewithin a source of magnetic flux and a first magnetic flux sensor disposed to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow, said source of magnetic flux and said first magnetic flux sensor being disposed such that, upon insertion of said card in said slot card reader, said mu-metal shield will interrupt said flow of magnetic flux to said sensor;

(c) inserting said card in said card reader, thereby permitting access to said computer;

(d) determining when said card is withdrawn from said slot card reader by detecting when said flow of magnetic flux is interrupted for a first interval upon insertion of said card in said slot card insertion reader and for a second interval upon removal of said card from said slot card insertion reader, said flow of magnetic flux being detected between said first and second intervals, and the determination of when said card is withdrawn occurs after the second resumption of said magnetic flux flow; and

(e) terminating said access to said computer system when said magnetic flux detection is resumed.

2. A method, as defined in claim 1, wherein said flow of magnetic flux is interrupted throughout the time said card is inserted in said slot card insertion reader.

18. A method, as defined in claim 1, wherein said card includes an identification code in the form of a bar code and wherein said bar code includes:

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

19. A method, as defined in claim 18, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.

3. A method of terminating access to a computer system, comprising:

(a) providing a mu-metal shield at a selected location in an identification card;

(b) providing a slot card insertion reader having disposed therewithin a source of magnetic flux and a first magnetic flux sensor disposed to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow, said source of magnetic flux and said first magnetic flux sensor being disposed such that, upon insertion of said card in said slot card reader, said mu-metal shield will interrupt said flow of magnetic flux to said sensor;

(c) inserting said card in said card reader, thereby permitting access to said computer;

(d) determining when said card is withdrawn from said slot card reader by detecting the resumption of said magnetic flux detection by said first sensor after the interruption thereof;

(e) providing in said slot card insertion reader a second magnetic flux sensor to detect the presence of a strong magnetic field, stronger than that produced by said source of magnetic flux; and

(e) terminating said access to said computer system either when said magnetic flux detection is resumed or when said strong magnetic field is detected.

4. A method, as defined in claim 3, wherein said flow of magnetic flux is interrupted throughout the time said card is inserted in said slot card insertion reader.

5. A method, as defined in claim 3, wherein said card includes an identification code in the form of a bar code and wherein said bar code includes:

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second dicipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

6. A method, as defined in claim 5, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.

7. A slot card reader for permitting access to a computer system in response to a card inserted therein, said card having a mu-metal shield at a selected location in said card, said slot card reader comprising:

(a) a source of magnetic flux;

(b) a magnetic flux sensor to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow;

(c) said source of magnetic flux and said magnetic flux sensor being disposed within said slot card reader such that, upon insertion of said card in said reader, said mu-metal shield will interrupt said flow of magnetic flux to said sensor, thereby indicating the validity of said card; and

(d) means to permit access to said computer system when said card is determined to be valid; and

wherein said card includes an identification code in the form of a bar code and wherein said bar code comprises;

(e) a first decipherable code containing first information encrypted according to a standard symbology;

(f) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(g) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(h) said second decipherable code being decipherable only with said unique decoding reader.

8. A slot card reader, as defined in claim 7, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.

9. A slot card insertion reader for terminating access to a computer system when an identification card has been removed therefrom, said card having a mu-metal shield at a selected location in said card, said slot card insertion reader comprising:

(a) a source of magnetic flux;

(b) a first magnetic flux sensor to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow;

(c) said source of magnetic flux and said first magnetic flux sensor being disposed within said slot card reader such that, upon insertion of said card in said reader, said mu-metal shield will interrupt said flow of magnetic flux to said first sensor for a first interval, and, upon removal of said card from said slot card insertion reader, said mu-metal shield will interrupt said flow of magnetic flux for a second interval, after which said flow of flux will resume, thereby indicating that said card has been withdrawn; and

(d) means to terminate access to said computer system when said flow of flux resumes.

10. A slot card insertion reader, as defined in claim 9, wherein said flow of magnetic flux is interrupted throughout the time said card is inserted in said slot card insertion reader.

20. A slot card insertion reader, as defined in claim 9, wherein said card includes an identification code in the form of a bar code and wherein said bar code includes:

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

21. A slot card insertion reader, as defined in claim 20, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.

11. A slot card insertion reader for terminating access to a computer system when an identification card has been removed therefrom, said card having a mu-metal shield at a selected location in said card, said slot card insertion reader comprising:

(a) a source of magnetic flux;

(b) a first magnetic flux sensor to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow;

(c) said source of magnetic flux and said first magnetic flux sensor being disposed within said slot card reader such that, upon insertion of said card in said reader, said mu-metal shield will interrupt said flow of magnetic flux to said first sensor, and, upon removal of said card from said slot card insertion reader, said flow of flux will resume, thereby indicating that said card has been withdrawn;

(d) a second magnetic flux sensor to detect the presence of a strong magnetic field, stronger than that produced by said source of magnetic flux; and

(e) means to terminate access to said computer system either when said flow of flux resumes or when said strong magnetic field is detected.

12. A slot card insertion reader, as defined in claim 11, wherein said flow of magnetic flux is interrupted throughout the time said card is inserted in said slot card insertion reader.

13. A slot card insertion reader, as defined in claim 11, wherein said card includes an identification code in the form of a bar code and wherein said bar code includes:

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

14. An identification card for use with a slot card reader for determining the validity of identification cards, said card reader including a source of magnetic flux, a magnetic flux sensor to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow, and said source of magnetic flux and said magnetic flux sensor being disposed within said slot card reader such that, upon insertion of an identification card, having a mu-metal shield disposed at a selected location in said card, in said reader, said mu-metal shield will interrupt said flow of magnetic flux to said sensor, thereby indicating the validity of said card, said identification card comprising a mu-metal shield disposed at said selected location;

and said identification card including an identification code in the form of a bar code and wherein said bar code includes;

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

15. An identification card, as defined in claim 14, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.

16. An identification card for use with a slot card insertion reader for determining when an identification card has been removed therefrom, said slot card insertion reader including a source of magnetic flux, a first magnetic flux sensor to detect the flow of said magnetic flux thereto and to produce an output signal indicative of the presence of said flow, said source of magnetic flux and said first magnetic flux sensor being disposed within said slot card reader such that, upon insertion of an identification card, having a mu-metal shield disposed at a selected location in said card, in said slot card insertion reader, said mu-metal shield will interrupt said flow of magnetic flux to said first sensor, and, upon removal of said card from said slot card insertion reader, said flow of flux will resume, thereby indicating that said card has been withdrawn, said identification card comprising a mu-metal shield disposed at said selected location;

and said identification card including an identification code in the form of a bar code and wherein said bar code includes;

(a) a first decipherable code containing first information encrypted according to a standard symbology;

(b) a second decipherable code containing second information encrypted according to a unique symbology, said second information including at least a portion of said first information;

(c) said first decipherable code being decipherable with either a standard decoding reader or a unique decoding reader; and

(d) said second decipherable code being decipherable only with said unique decoding reader.

17. An identification card, as defined in claim 16, wherein:

(a) said first decipherable code is an identification code; and

(b) said second decipherable code is a security code.