← Back to Patent Explorer
US4944009A Expired / Lapsed US ⏱️ 0.0 years remaining

Pseudo-random sequence generator

Assignee: Massachusetts Institute of Technology
•
Filing: 1988-02-25
•
Granted: 1990-07-24
•
Expires: 2008-02-25
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A seed random sequence is extended in successive nodes of a tree structure of a random sequence generator. At each node, an input sequence is expanded to an output sequence substantially greater than the length of the input sequence. Plural processors operate in parallel in generating the final output sequence, and subsequences may be directly accessed as a starting location of the output sequence. The random sequence generator is accessed by an index in an encryption system. In a sequential generator, less than all of the bits from the generator unit are reapplied to the generator unit in an iterative process.

Inventors

  • 👤 Silvio Micali
  • 👤 Claus Schnorr

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 21:12
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/06; H04L9/065; H04L9/0656; H04L9/0662; H04L2209/00; H04L2209/12; H04L2209/125; H04L2209/26

Claims Analysis

Total Claims: 70
Claim 1
Independent Claim 63 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a plurality of node output random sequences of the tree structure together comprising a final random output sequence.
Claim 2
Dependent Claim 63 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a plurality of node output random sequences of the tree structure together comprising a final random output sequence.
Claim 3
Dependent Claim 61 words
A random sequence generator as claimed in claim 1 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y.
Claim 4
Dependent Claim 52 words
A random sequence generator as claimed in claim 2 wherein there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 5
Dependent Claim 22 words
A random sequence generator as claimed in claim 2 where N is the product of two large random primes p and q.
Claim 6
Dependent Claim 40 words
A random sequence generator as claimed in claim 4 wherein at least one a d of a e , a e-1 , . . . ,a 3 is nonzero, and d is an integer that is relatively prime to (p-1)(q-1).
Claim 7
Dependent Claim 27 words
A random sequence generator as claimed in claim 5 wherein all coefficients of the polynomial of y are equal to zero except the coefficient a 3 .
Claim 8
Dependent Claim 16 words
A random sequence generator as claimed in claim 6 where a 3 is equal to one.
Claim 9
Dependent Claim 58 words
A random sequence generator as claimed in claim 1 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 10
Dependent Claim 15 words
A random sequence generator as claimed in claim 8 wherein d is equal to 3.
Claim 11
Dependent Claim 21 words
A random sequence generator as claimed in claim 1 wherein each node input sequence is extended by a single modular operation.
Claim 12
Dependent Claim 30 words
A random sequence generator as claimed in claim 1 wherein less than all of the bits of node output sequences are reapplied as node input sequences of the tree structure.
Claim 13
Dependent Claim 59 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a final random output sequence being generated as successive leaves of the tree structure.
Claim 14
Dependent Claim 59 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a final random output sequence being generated as successive leaves of the tree structure.
Claim 15
Dependent Claim 58 words
A random sequence generator as claimed in claim 12 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 16
Dependent Claim 15 words
A random sequence generator as claimed in claim 13 wherein d is equal to 3.
Claim 17
Dependent Claim 21 words
A random sequence generator as claimed in claim 12 wherein each node input sequence is extended by a single modular operation.
Claim 18
Dependent Claim 105 words
A random sequence generator as claimed in claim 12 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 19
Dependent Claim 80 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator comprising a plurality of processors, each processor extending a node input random sequence into a longer node output random sequence, each of the plurality of processors performing a portion of a tree structure by extending a node input sequence and then separately extending different portions of a node output sequence in successive operations at successive nodes of the tree structure.
Claim 20
Dependent Claim 80 words
A random sequence generator for generating a random sequence from a seed random sequence of substantially shorter length, the generator comprising a plurality of processors, each processor extending a node input random sequence into a longer node output random sequence, each of the plurality of processors performing a portion of a tree structure by extending a node input sequence and then separately extending different portions of a node output sequence in successive operations at successive nodes of the tree structure.
Claim 21
Dependent Claim 58 words
A random sequence generator as claimed in claim 17 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 22
Dependent Claim 15 words
A random sequence generator as claimed in claim 18 wherein d is equal to 3.
Claim 23
Dependent Claim 21 words
A random sequence generator as claimed in claim 17 wherein each node input sequence is extended by a single modular operation.
Claim 24
Dependent Claim 105 words
A random sequence generator as claimed in claim 17 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where (N) is Euler's Totient function.
Claim 25
Independent Claim 56 words
A method of generating a random sequence from a seed random sequence of substantially shorter length, comprising performing a tree operation by extending, at each node of the tree structure, a node input random sequence into a longer node output random sequence, a final random output sequence being generated from successive leaves of the tree structure.
Claim 26
Independent Claim 56 words
A method of generating a random sequence from a seed random sequence of substantially shorter length, comprising performing a tree operation by extending, at each node of the tree structure, a node input random sequence into a longer node output random sequence, a final random output sequence being generated from successive leaves of the tree structure.
Claim 27
Dependent Claim 56 words
A method as claimed in claim 22 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 28
Dependent Claim 13 words
A method as claimed in claim 23 wherein d is equal to 3.
Claim 29
Dependent Claim 19 words
A method as claimed in claim 22 wherein each node input sequence is extended by a single modular operation.
Claim 30
Dependent Claim 105 words
A random sequence generator as claimed in claim 22 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 31
Independent Claim 60 words
A method of generating a random sequence from a seed random sequence of substantially shorter length comprising performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a plurality of node output random sequences of the tree structure together comprising a final random output sequence.
Claim 32
Independent Claim 60 words
A method of generating a random sequence from a seed random sequence of substantially shorter length comprising performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence, a plurality of node output random sequences of the tree structure together comprising a final random output sequence.
Claim 33
Dependent Claim 56 words
A method as claimed in claim 27 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 34
Dependent Claim 13 words
A method as claimed in claim 28 wherein d is equal to 3.
Claim 35
Dependent Claim 19 words
A method as claimed in claim 27 wherein each node input sequence is extended by a single modular operation.
Claim 36
Dependent Claim 105 words
A random sequence generator as claimed in claim 27 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 37
Independent Claim 77 words
A method of generating a random sequence from a seed random sequence of substantially shorter length comprising in each of a plurality of processors, extending a node input random sequence into a longer node output random sequence, each of the plurality of processors performing a portion of a tree structure by extending a node input sequence and then separately extending different portions of a node output sequence in successive operations at successive nodes of the tree structure.
Claim 38
Independent Claim 77 words
A method of generating a random sequence from a seed random sequence of substantially shorter length comprising in each of a plurality of processors, extending a node input random sequence into a longer node output random sequence, each of the plurality of processors performing a portion of a tree structure by extending a node input sequence and then separately extending different portions of a node output sequence in successive operations at successive nodes of the tree structure.
Claim 39
Dependent Claim 56 words
A method as claimed in claim 32 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 40
Dependent Claim 13 words
A method as claimed in claim 33 wherein d is equal to 3.
Claim 41
Dependent Claim 19 words
A method as claimed in claim 32 wherein each node input sequence is extended by a single modular operation.
Claim 42
Dependent Claim 105 words
A random sequence generator as claimed in claim 32 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 43
Dependent Claim 70 words
An encryption system comprising an encryption unit for performing a transform between encrypted and nonencrypted messages, based on an extended random sequence, and a random sequence generator for generating the random sequence from a seed random sequence and an index input, the random sequence generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence.
Claim 44
Dependent Claim 70 words
An encryption system comprising an encryption unit for performing a transform between encrypted and nonencrypted messages, based on an extended random sequence, and a random sequence generator for generating the random sequence from a seed random sequence and an index input, the random sequence generator performing a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence.
Claim 45
Dependent Claim 57 words
An encryption system as claimed in claim 37 wherein each node input sequence is extended by the operation y=ax.sup.d (mod N) where N is the product of two large random primes p and q, d is an integer that is relatively prime to (p-1)(q-1), the node input sequence represents x and the node output sequence represents y.
Claim 46
Dependent Claim 14 words
An encryption system as claimed in claim 38 wherein d is equal to 3.
Claim 47
Dependent Claim 20 words
An encryption system as claimed in claim 37 wherein each node input sequence is extended by a single modular operation.
Claim 48
Dependent Claim 29 words
An encryption system as claimed in claim 37 wherein the random sequence applied to the encryption unit comprises a plurality of node output random sequences of the tree structure.
Claim 49
Dependent Claim 26 words
An encryption system as claimed in claim 41 wherein the random sequence applied to the encryption unit is generated as successive leaves of the tree structure.
Claim 50
Dependent Claim 31 words
An encryption system as claimed in claim 37 wherein the random sequence generator comprises a plurality of processors, each of the plurality of processors performing a portion of the tree structure.
Claim 51
Dependent Claim 105 words
A random sequence generator as claimed in claim 37 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 52
Independent Claim 64 words
A method of message encryption comprising generating a random sequence from a seed random sequence and an index input, the random sequence being generated in a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence and, based on the extended random sequence, performing a transform between encrypted and nonencrypted messages.
Claim 53
Independent Claim 64 words
A method of message encryption comprising generating a random sequence from a seed random sequence and an index input, the random sequence being generated in a tree operation by extending, at each node of a tree structure, a node input random sequence into a longer node output random sequence and, based on the extended random sequence, performing a transform between encrypted and nonencrypted messages.
Claim 54
Dependent Claim 19 words
A method as claimed in claim 45 wherein each node input sequence is extended by a single modular operation.
Claim 55
Dependent Claim 28 words
A method as claimed in claim 45 wherein the random sequence applied to the encryption unit comprises a plurality of node output random sequences of the tree structure.
Claim 56
Dependent Claim 25 words
A method as claimed in claim 47 wherein the random sequence applied to the encryption unit is generated as successive leaves of the tree structure.
Claim 57
Dependent Claim 30 words
A method as claimed in claim 45 wherein the random sequence generator comprises a plurality of processors, each of the plurality of processors performing a portion of the tree structure.
Claim 58
Dependent Claim 105 words
A random sequence generator as claimed in claim 45 wherein each node input sequence is extended by the operation y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the node input sequence represents x and the node output sequence represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 59
Independent Claim 68 words
A method of generating a random sequence from a random seed comprising, in each of iterative steps, applying a function to an input string of random bits to obtain an output string of bits, significantly less than all of an output string of bits being used in an input string of bits in each successive step, and utilizing other bits of the output string toward the random sequence.
Claim 60
Independent Claim 68 words
A method of generating a random sequence from a random seed comprising, in each of iterative steps, applying a function to an input string of random bits to obtain an output string of bits, significantly less than all of an output string of bits being used in an input string of bits in each successive step, and utilizing other bits of the output string toward the random sequence.
Claim 61
Dependent Claim 27 words
A method as claimed in claim 51 wherein each input string is about 2/3 or less of the bits of the output string from the previous step.
Claim 62
Dependent Claim 24 words
A method as claimed in claim 51 wherein the other bits utilized toward the random sequence are a part of the generated random sequence.
Claim 63
Dependent Claim 36 words
A method as claimed in claim 51 wherein the iterative steps are performed in a tree operation and the function is also applied to the other bits of the output string utilized toward the random sequence.
Claim 64
Dependent Claim 76 words
A method as claimed in claim 51 wherein each output string of bits is obtained by the function y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the input string represents x and the output string represents y and where the number of bits in x is significantly less than the number of bits in N.
Claim 65
Dependent Claim 104 words
A random sequence generator as claimed in claim 51 wherein each input string of bits is extended by the function y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the input string represents x and the output string represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.
Claim 66
Independent Claim 74 words
A method of generating a random sequence from a random seed comprising, in each of iterative steps, applying a function to an input string of random bits to obtain an output string of bits, significantly less than all of an output string of bits being used as an input string of bits in each successive step, at least some of the bits of each output string being a part of the generated random sequence.
Claim 67
Independent Claim 74 words
A method of generating a random sequence from a random seed comprising, in each of iterative steps, applying a function to an input string of random bits to obtain an output string of bits, significantly less than all of an output string of bits being used as an input string of bits in each successive step, at least some of the bits of each output string being a part of the generated random sequence.
Claim 68
Dependent Claim 27 words
A method as claimed in claim 57 wherein each input string is about 2/3 or less of the bits of the output string from the previous step.
Claim 69
Dependent Claim 76 words
A method as claimed in claim 57 wherein each output string of bits is obtained by the function y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the input string represents x and the output string represents y and where the number of bits in x is significantly less than the number of bits in N.
Claim 70
Dependent Claim 104 words
A random sequence generator as claimed in claim 57 wherein each input string of bits is extended by the function y=a.sub.e x.sup.e +a.sub.e-1 x.sup.e-1 + . . . +a.sub.1 x+a.sub.0 (mod N) where e, a e , a e-1 , . . . ,a 0 and N are integers, the input string represents x and the output string represents y, and where there is at least one a d of a e , a e-1 , . . . ,a 3 not equal to zero and the greatest common divisor of d and φ(N) is equal to one where φ(N) is Euler's Totient function.

References Cited (Backward Citations)

US4405829A Cited
SU785859A1 Cited
US4208739A Cited
CA1174364A Cited
DE3339985A1 Cited
US4799259A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-07-23 1994-01-22 1994-07-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-07-23 1998-01-22 1998-07-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-07-23 2002-01-22 2002-07-24 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag