METHOD OF GENERATING SUCCESSIONS OF PSEUDO-RANDOM BITS OR NUMBERS

• US 20060251250A1
• Filed: 05/03/2006
• Published: 11/09/2006
• Est. Priority Date: 05/03/2005
• Status: Abandoned Application

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Ruggiero, Davide, Pedaci, Immacolata, Mascolo, Danilo, Amato, Paolo
• Application Number:
  US11/381,474
• Publication Number:
  US 20060251250A1
• Time in Patent Office: Days
• US Class Current: 380/46
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 9/001 using chaotic signals
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator

Abstract

A method for generating a succession of pseudo-random numbers includes choosing at least one chaotic map, and choosing a seed for the chaotic map and a number of iterations for the chaotic map. The succession of pseudo-random numbers are generated by executing iteratively generating a pseudo-random number as a function of a final state reached by the chaotic map iterated for the current number of iterations starting from the current seed, and generating a new seed for the chaotic map or a new number of iterations as a function of the final state.

Claims

1-14. -14. (canceled)

15. A method for generating a succession of pseudo-random numbers comprising:

choosing at least one chaotic map;

choosing a seed for the chaotic map and a number of iterations for the chaotic map;

generating the succession of pseudo-random numbers executing iteratively the following;

a) generating a pseudo-random number as a function of a final state reached by the chaotic map iterated for the current number of iterations starting from the current seed, and

b) generating a new seed for the chaotic map or a new number of iterations as a function of the final state

16. A method according to claim 15, further comprising choosing a first function defined on a phase space of the chaotic map and having values in it, and a second nonlinear function defined on the phase space of the chaotic map and with values in a set of natural numbers;

and wherein generating the new seed or the new number comprises applying respectively the first and second functions on the final state.

17. A method according to claim 15, wherein choosing at least one chaotic map comprises choosing a plurality of chaotic maps and as many seeds and numbers of iterations;

and further comprising;

choosing a third function;

generating an intermediate succession of pseudo-random numbers for each chaotic map; and

generating each pseudo-random number of the intermediate succession by combining with the third function the pseudo-random numbers that are currently generated by each of the chaotic maps.

18. A method according to claim 17, wherein the first and second functions are chosen for each chaotic map.

19. A method according to claim 15, wherein the pseudo-random numbers generated by the chaotic map are obtained by multiplying by a pre-established power of ten a sum of an absolute value of the components of the state reached by the chaotic map after the number of literations and keeping only the integer part of the product.

20. A method according to claim 15, wherein in a phase space of the chaotic map there is at least one attractor basin and the seed is chosen from inside the attractor basin.

21. A method for generating a pseudo-random succession of numbers or bits in a pre-established base, the method comprising:

choosing a plurality of chaotic maps and as many seeds and numbers of iterations;

choosing a function;

generating an intermediate succession of pseudo-random numbers for the plurality of chaotic maps;

generating each pseudo-random number of the intermediate succession by combining with the function the pseudo-random numbers that are currently generated by each of the chaotic maps;

generating the succession of pseudo-random numbers executing iteratively the following;

a) generating a pseudo-random number as a function of a final state reached by the plurality of chaotic maps iterated for the current number of iterations starting from a current seed, and

b) generating a new seed for the plurality of chaotic maps or a new number of iterations as a function of the final state.

22. A method according to claim 21, further comprising:

converting each pseudo-random number currently generated by each chaotic map in a respective intermediate bit or intermediate number in the pre-established base;

generating a string of bits or numbers in the pre-established base comprising respectively of the intermediate bit or intermediate numbers in the pre-established base obtained above; and

generating a respective pseudo-random bit or a pseudo-random number in the pre-established base for the succession to be generated respectively as a function of the string of bits or numbers.

23. A computer-readable medium having computer-executable instructions for causing a computer to perform steps comprising:

choosing at least one chaotic map;

choosing a seed for the chaotic map and a number of iterations for the chaotic map;

generating the succession of pseudo-random numbers executing iteratively the following;

a) generating a pseudo-random number as a function of a final state reached by the chaotic map iterated for the current number of iterations starting from the current seed, and

b) generating a new seed for the chaotic map or a new number of iterations as a function of the final state.

24. A computer-readable medium according to claim 23, further comprising choosing a first function defined on a phase space of the chaotic map and having values in it, and a second nonlinear function defined on the phase space of the chaotic map and with values in a set of natural numbers;

and wherein generating the new seed or the new number comprises applying respectively the first and second functions on the final state.

25. A computer-readable medium according to claim 23, wherein choosing at least one chaotic map comprises choosing a plurality of chaotic maps and as many seeds and numbers of iterations;

and further comprising;

choosing a third function;

generating an intermediate succession of pseudo-random numbers for each chaotic map; and

generating each pseudo-random number of the intermediate succession by combining with the third function the pseudo-random numbers that are currently generated by each of the chaotic maps.

26. A computer-readable medium according to claim 25, wherein the first and second functions are chosen for each chaotic map.

27. A computer-readable medium according to claim 23, wherein the pseudo-random numbers generated by the chaotic map are obtained by multiplying by a pre-established power of ten a sum of an absolute value of the components of the state reached by the chaotic map after the number of iterations, and keeping only the integer part of the product.

28. A computer-readable medium according to claim 23, wherein in a phase space of the chaotic map there is at least one attractor basin and the seed is chosen from inside the attractor basin.

29. A device for generating a succession of pseudo-random numbers or bits comprising:

a processor for executing the following choosing at least one chaotic map, choosing a seed for the chaotic map and a number of iterations for the chaotic map, generating the succession of pseudo-random numbers executing iteratively the following

a) generating a pseudo-random number as a function of a final state reached by the chaotic map iterated for the current number of iterations starting from the current seed, and

b) generating a new seed for the chaotic map or a new number of iterations as a function of the final state.

30. A device according to claim 29, wherein said processor chooses a first function defined on a phase space of the chaotic map and having values in it, and a second nonlinear function defined on the phase space of the chaotic map and with values in a set of natural numbers;

and wherein generating the new seed or the new number comprises applying respectively the first and second functions on the final state.

31. A device according to claim 29, wherein choosing at least one chaotic map by said processor comprises choosing a plurality of chaotic maps and as many seeds and numbers of iterations;

and wherein said processor further performs the following;

choosing a third function;

generating an intermediate succession of pseudo-random numbers for each chaotic map; and

generating each pseudo-random number of the intermediate succession by combining with the third function the pseudo-random numbers that are currently generated by each of the chaotic maps.

32. A device according to claim 31, wherein the first and second functions are chosen by said processor for each chaotic map.

33. A device according to claim 29, wherein the pseudo-random numbers generated by the chaotic map are obtained by multiplying by a pre-established power of ten a sum of an absolute value of the components of the state reached by the chaotic map after the number of iterations, and keeping only the integer part of the product

34. A device according to claim 29, wherein in a phase space of the chaotic map there is at least one attractor basin and the seed is chosen from inside the attractor basin

35. An architecture for encrypting/decrypting packets of bits to be transmitted or received, the architecture comprising:

a device for generating a communication key comprising pseudo-random bits;

a generator for generating an encryption/decryption string as a function of the communication key;

an encoding XOR gate for generating a succession of encrypted bits to be transmitted as logic XOR among bits of the encryption/decryption string and bits of at least a packet of bits to be transmitted; and

a decoding XOR gate for generating a succession of decoded bits as a logic XOR among the bits of the encryption/decryption string and bits of at least a packet of bits encoded and received.

36. An architecture according to claim 35, wherein said generator comprises:

a stream cipher configured as a self-shrinked type for generating an intermediate string; and

a logic circuit being input with the intermediate string, and generating the encryption/decryption string according to a nonlinear Boolean function.

37. An architecture according to claim 35, wherein the encrypting/decrypting string is identical to communication key.

38. An architecture according to claim 35, wherein said device for generating the communication key comprises a processor for performing the following:

choosing at least one chaotic map, choosing a seed for the chaotic map and a number of iterations for the chaotic map, generating the succession of pseudo-random numbers executing iteratively the following

a) generating a pseudo-random number as a function of a final state reached by the chaotic map iterated for the current number of iterations starting from the current seed, and

b) generating a new seed for the chaotic map or a new number of iterations as a function of the final state

39. An architecture according to claim 38, wherein said processor chooses a first function defined on a phase space of the chaotic map and having values in it, and a second nonlinear function defined on the phase space of the chaotic map and with values in a set of natural numbers;

and wherein generating the new seed or the new number comprises applying respectively the first and second functions on the final state.

40. An architecture according to claim 38, wherein choosing at least one chaotic map by said processor comprises choosing a plurality of chaotic maps and as many seeds and numbers of iterations;

and wherein said processor further performs the following;

choosing a third function;

generating an intermediate succession of pseudo-random numbers for each chaotic map; and

generating each pseudo-random number of the intermediate succession by combining with the third function the pseudo-random numbers that are currently generated by each of the chaotic maps.

41. An architecture according to claim 38, wherein the first and second functions are chosen by said processor for each chaotic map.

42. An architecture according to claim 38, wherein the pseudo-random numbers generated by the chaotic map are obtained by multiplying by a pre-established power of ten a sum of an absolute value of the components of the state reached by the chaotic map after the number of iterations, and keeping only the integer part of the product

43. An architecture according to claim 38, wherein in a phase space of the chaotic map there is at least one attractor basin and the seed is chosen from inside the attractor basin.