Method and apparatus for generating encryption/decryption key

• US 4,878,246 A
• Filed: 05/02/1988
• Issued: 10/31/1989
• Est. Priority Date: 05/02/1988
• Status: Expired due to Term

• Current Assignee: Pitney Bowes Incorporated (Böwe Systec AG)
• Original Assignee: Pitney Bowes Incorporated (Böwe Systec AG)
• Inventors: Barton, Maya R., Pastor, Jose
• Primary Examiner(s): Cangialosi, Salvatore
• Application Number:
  US07/188,866
• Time in Patent Office: 547 Days
• Field of Search: 380/44, 380/47, 380/50
• US Class Current: 380/44
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner

Abstract

An encryption/decryption key is generated from an identification number ID by first generating two sets of numbers from the identification number ID, based upon known expressions. The first set of numbers are employed as coefficients of a first polynomial to generate N first numbers for x=0, 1 . . . N-1 (N is the number of bits of the key) and a second number corresponding to each first number is generating employing the second set of numbers as coefficients and the generated first numbers as variables. The ordered pairs of first and second numbers generated correspond to addresses of a memory at which bits of the key are stored, the order of the bits being determined by the corresponding values of X. The expressions employ modular arithmetic using prime numbers as bases.

Claims

1. A method for generating a key code from an identification number ID, said key having N bits, comprising

generating a first plurality of numbers, modulus A and a second plurality of numbers, modulus B, from ID, in accordance with a set of algorithms, wherein A and B are prime numbers with A greater than N-1;

generating N values y(x), mod A, from a first polynomial having said first plurality of numbers as coefficients and x as a variable, wherein x is an integer from 0 to N-1;

generating a value z(y), mod B, from a second polynomial having said third, fourth and fifth numbers as coefficients and y as a variable, corresponding to each value of y(x)

accessing a memory at addresses as determined as function of y,z corresponding to each value of x to retrieve data therein, and reordering said data as a function of the value of x to produce said key.

2. A device for generating a key code from an identification number ID, said key having N bits, comprising:

means for generating a first plurality of numbers, modulus A and a second plurality of numbers, modulus B, from ID, in accordance with a set of algorithms, wherein A and B are prime numbers, with A greater than N-1;

means for generating N values y(x), mod A, from a first polynomial having said first plurality of numbers as coefficients and x as a variable, wherein x is an integer from 0 to N-1;

means for generating a value z(y), mod B, from a second polynomial having said second plurality of numbers as coefficients and y as a variable, corresponding to each value of y(x), and;

means for accessing a memory at addresses determined as a function of y,z corresponding to each value of x to retrieve data therein, and reordering said data as a function of the value of x to produce said key.

3. Means for generating corresponding keys at first and second stations from an identification number ID, said key having N bits, comprising:

means at each of said first and second stations for generating an identical first plurality of numbers, modulus A and an identical second plurality of numbers, modulus B, from ID, in accordance with a set of algorithms, wherein A and B are prime numbers, and A is greater than N-1;

means at each station for generating identical N values y(x), mod A, from a first polynomial having said first plurality of numbers as coefficients and x as a variable, wherein x is an integer from 0 to N-1;

means at each station for generating an identical value z(y), mod B, from a second polynomial having said second plurality of numbers as coefficients and y as a variable, corresponding to each value of y(x); and

,

means at each station for accessing a memory at addresses determined as a function of y,z corresponding to each value of x to retrieve data therein, and reordering said data as a function of the value of x to produce said key.

4. A method for generating a key code having N elements and corresponding to a number, ID, comprising the steps of:

(a) generating a unique sequence of N memory addresses as a modular function of said number ID; and

,

(b) accessing memory cells in accordance with said sequence of memory addresses and retrieving code elements stored therein;

(c) whereby the resulting sequence of code elements constitutes said key code; and

wherein,

(d) the number of said memory cells is substantially greater than N, and cells other than said accessed cells contain randomly selected code elements.

5. The method of claim 4 wherein the number of said cells is M, comprisng the further steps of:

(a) providing a second memory having M cells;

(b) randomly storing the addresses of said cells in said first memory in said cells of said second memory; and

;

(c) wherein step (a) further comprises generating a unique sequence of N memory addresses for said cells of said second memory as a function of said number ID and retrieving the corresponding sequence of addresses for said cells of said first memory from said addressed cells of said second memory.

6. The method of claim 5 wherein M=A*B, and A and B are prime numbers, and A is the smallest prime number greater than N-1.

7. The method of claim 6 wherein said step of generating said sequence of addresses or said second memory comprises the further steps of:

(a) generating a unique series of N column addresses y for A columns of said second memory as a function of said number ID and a variable x, where each value of x corresponds to one element of said key code;

(b) generating a unique series of N row addresses for B rows of said second memory as a function of said number ID and y_i and

(c) for each element of said key code selecting said address for said cells in said first memory to be said address stored in the row and column of said second memory defined by said corresponding value of x.

8. The method of claim 6 wherein said number ID is, at least in part, defined by the identity of a user of said key code.

9. The method of claim 6 wherein said number ID is, at least in part, defined by a sequence number identified in a particular use of said key code.

10. The method of claim 4 wherein said number ID is, at least in part, defined by the identity of a user of said key code.

11. The method of claim 4 wherein said number ID is, at least in part, defined by a sequence number identified in a particular use of said key code.

12. Apparatus for generating key code having N elements and corresponding to a number, ID, comprising:

(a) means for generating a unique sequence of N memory addresses as a modular function of said number ID, and;

(b) means for accessing memory cells in a memory in accordance wih said sequence of memory addresses and retrieving code elements stored therein;

(c) whereby the resulting sequence of code elements constitutes said key codes; and

wherein,

(d) the number of said memory cells is substantially greater than N, and cells other than said accessed cells contain randomly selected code elements.

13. The apparatus of claim 12 wherein the number of said cells is M, comprising:

(a) a second memory having M cells;

(b) said second memory randomly storing the addresses of said cells in said first memory in cells of said second memory, and;

(c) wherein said generating means further comprises means for generating a unique sequence of N memory addresses for said cells of said second memory as a function of said number 10 and retrieving the corresponding sequence of addresses for said cells of said first memory from said addresses cells of said second memory.

14. The apparatus of claim 13 wherein M=A*B, and A and B are prime numbers, and A is the smallest prime number greater than N-1.

15. The apparatus of claim 14 wherein said further generating means still further comprises:

(a) means for generating a unique series of N column address y for A columns of said second memory as a function of said number ID and a variable x, where each value of x corresponds to one element of said key code;

(b) means for generating a unique series of N row addresses for B rows of said second memory as a function of said number ID and y_i and

(c) means for each element of said key code, selecting said address for said cells in said first memory to be said address stored in the row and column of said second memory defined by said corresponding value of x.

16. The apparatus of claim 14 wherein said number ID is, at least in part, defined by the identity of a user of said key code.

17. The apparatus of claim 14 wherein said number ID is, at least in part, defined by a sequence number identify in a particlar use of said key code.

18. The apparatus of claim 12 wherein said number ID is, at least in part, defined by the identity of a user of said key code.

19. The apparatus of claim 12 wherein said number ID is, at least in part, defined by a sequence number identify in a particular use of said key code.