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US4935962A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and system for authentication

Assignee: NCR Voyix Corp
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Filing: 1989-06-12
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Granted: 1990-06-19
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Expires: 2009-06-12
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Abstract

Abstract An entity such as a smart card includes microprocessor means, input/output means, and PROM storage means which stores a set of transformations S i (i=1, . . . , n) of a corresponding set of public factors F 1 (i=1, . . . , n), where S i =F i d (mod N), d being the secret key counterpart of a public key e associated with the modulus N, which is the product of two primes. An authentication device which stores the public factors F i and the values of N and e, generates an n bit random vector v=v i which is transmitted to the card where a product Y of the values S i selected according to the 1 bits of v is computed and transmitted to the authentication device which computes X act =Y e (mod N) and also computes X ref , the product of the F i selected according to the 1 bits of v. If X act and X ref are equal, then the card is authenticated to within a certain probability. An analogous method is disclosed for certifying messages to be transmitted. In further embodiments, a higher degree of security is achieved by arranging for the entity being authenticated, or the certifying entity, to select an additional secret factor or plurality of secret factors.

Inventors

  • 👤 Jeffrey R. Austin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 08:05
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/10; G07F7/1008; G06; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/341; G06Q20/36; G06Q20/367; G06Q20/3674; G06Q20/38; G06Q20/40; G06Q20/409; G06Q20/4097; G06Q20/40975; G07F7/1016; H; H04; H04L; H04L9/00; H04L9/30; H04L9/3006; H04L9/302; H04L9/32; H04L9/3234; H04L9/3236; H04L9/3242; H04L2209/00; H04L2209/56

Claims Analysis

Total Claims: 35
Claim 1
Independent Claim 111 words
A method for preparing an entity to be authenticated by an authenticating device including: selecting a modulus N which is a product of two or more prime numbers; selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; determining an integer d such that e·d =1 (mod Φ(N)); selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; calculating S i =F i d (mod N) for i=1, . . , n; and storing the n values S i , i=1, . . . , n, and the value N in said entity.
Claim 2
Independent Claim 111 words
A method for preparing an entity to be authenticated by an authenticating device including: selecting a modulus N which is a product of two or more prime numbers; selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; determining an integer d such that e·d =1 (mod Φ(N)); selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; calculating S i =F i d (mod N) for i=1, . . , n; and storing the n values S i , i=1, . . . , n, and the value N in said entity.
Claim 3
Dependent Claim 25 words
A method according to claim 1 wherein said entity includes a PROM, said method further comprising: storing said n values S i in said PROM.
Claim 4
Dependent Claim 17 words
A method according to claim 2 further comprising: providing said entity with processing means and input/output means.
Claim 5
Dependent Claim 34 words
A method according to claim 1 further comprising: assigning a public factor F ID unique to said entity; computing S ID=F ID d (mod N); and storing the value S ID in said entity.
Claim 6
Independent Claim 187 words
A method of authenticating an entity by an authentication device comprising: (a) selecting a modulus N which is a product of two or more prime numbers; (b) selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; (c) determining an integer d such that e·d=1 (mod Φ(N)); (d) selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; (e) calculating S i =F i d (mod N) for i=1, . . . , n; (f) storing the n values S i , i=1, . . . , n), and the value N in said entity; (g) placing said entity in communication with said authentication device; (h) generating in said authentication device an n bit binary string v=v i (i=1, . . . , n); (i) transmitting said binary string v to said entity; (h) calculating in said entity ##EQU22## (k) transmitting Y to said authentication device; (l) calculating in said authentication device: X ref ##EQU23## and X.sub.act =Y.sup.e (mod N); and (m) comparing X ref and X act .
Claim 7
Independent Claim 187 words
A method of authenticating an entity by an authentication device comprising: (a) selecting a modulus N which is a product of two or more prime numbers; (b) selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; (c) determining an integer d such that e·d=1 (mod Φ(N)); (d) selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; (e) calculating S i =F i d (mod N) for i=1, . . . , n; (f) storing the n values S i , i=1, . . . , n), and the value N in said entity; (g) placing said entity in communication with said authentication device; (h) generating in said authentication device an n bit binary string v=v i (i=1, . . . , n); (i) transmitting said binary string v to said entity; (h) calculating in said entity ##EQU22## (k) transmitting Y to said authentication device; (l) calculating in said authentication device: X ref ##EQU23## and X.sub.act =Y.sup.e (mod N); and (m) comparing X ref and X act .
Claim 8
Dependent Claim 70 words
A method according to claim 5, wherein in said step (j) the value of Y is calculated utilizing selectively an additional predetermined factor S p , such that the total number of factors included in the calculation of Y is even, and wherein in said step (1), the value of X ref is correspondingly calculated. utilizing selectively an additional factor F p , where S p =F p d .
Claim 9
Dependent Claim 34 words
A method according to claim 5 further comprising: storing said said public factors F 1 , . . . , F n , and the values of N and e in said authentication device.
Claim 10
Dependent Claim 23 words
A method according to claim 7 further comprising: repeating said steps (h) to (m) a plurality of times, using random values of v.
Claim 11
Independent Claim 151 words
A method of certifying a message M by an entity comprising: selecting a modulus N which is a product of two or more prime numbers; selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; determining an integer d such that e·d=1 (mod Φ(N)); selecting a set of n public factors F 1 , . . . , F n , 0<F i<N; calculating S i=F i d (mod N) for i=1, . . . , n; storing the n values S i , i=1, . . . , n, and the value N in said entity computing a change sensitive transformation H of said message M; generating an n bit binary string v=v i , i=1, . . . , n, using the computed value of H; computing ##EQU24## and appending Y as a message authentication code certificate to said message M.
Claim 12
Independent Claim 151 words
A method of certifying a message M by an entity comprising: selecting a modulus N which is a product of two or more prime numbers; selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; determining an integer d such that e·d=1 (mod Φ(N)); selecting a set of n public factors F 1 , . . . , F n , 0<F i<N; calculating S i=F i d (mod N) for i=1, . . . , n; storing the n values S i , i=1, . . . , n, and the value N in said entity computing a change sensitive transformation H of said message M; generating an n bit binary string v=v i , i=1, . . . , n, using the computed value of H; computing ##EQU24## and appending Y as a message authentication code certificate to said message M.
Claim 13
Dependent Claim 48 words
A method according to claim 9 wherein said step of generating an n bit binary string v includes: converting H to a binary value J; segmenting J into subfields of length n; and adding together the individual subfields modulo 2 to for said n bit binary string v.
Claim 14
Dependent Claim 21 words
A method according to claim 9 wherein said step of computing a change sensitive transformation H includes: computing H=M.sup.e (mod N).
Claim 15
Dependent Claim 48 words
A method according to claim 11 wherein said step of generating an n bit binary string v includes: converting H to a binary value J; segmenting J into subfields of length n; and adding together the individual subfields modulo 2 to form said n bit binary string v.
Claim 16
Independent Claim 208 words
A method of authenticating an entity by an authentication device comprising: (a) selecting a modulus N which is a product of two or more prime numbers; (b) selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; (c) determining an integer d such that e·d=1 (mod Φ(N)); (d) selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; (e) calculating S i=F i d (mod N) for i=1, . . . , n; (f) storing the n values S i , i=1, . . . , n, and the value N in said entity; (g) placing said entity in communication with said authentication device; (h) generating in said authentication device an n bit binary string v=v i , i=1, . . . , n; (i) transmitting said binary string v to said entity; (j) selecting a value S set in said entity and computing in said entity F set =S set e ; (k) calculating in said entity ##EQU25## (l) transmitting Y and F set to said authentication device; (m) calculating in said authentication device: ##EQU26## and X.sub.act =Y.sup.e (mod N); and (n) comparing X ref and X act .
Claim 17
Independent Claim 208 words
A method of authenticating an entity by an authentication device comprising: (a) selecting a modulus N which is a product of two or more prime numbers; (b) selecting an integer e which is relatively prime to Φ(N), where Φ(N) is Euler's totient function of N; (c) determining an integer d such that e·d=1 (mod Φ(N)); (d) selecting a set of n public factors F 1 , . . . , F n , 0<F i <N; (e) calculating S i=F i d (mod N) for i=1, . . . , n; (f) storing the n values S i , i=1, . . . , n, and the value N in said entity; (g) placing said entity in communication with said authentication device; (h) generating in said authentication device an n bit binary string v=v i , i=1, . . . , n; (i) transmitting said binary string v to said entity; (j) selecting a value S set in said entity and computing in said entity F set =S set e ; (k) calculating in said entity ##EQU25## (l) transmitting Y and F set to said authentication device; (m) calculating in said authentication device: ##EQU26## and X.sub.act =Y.sup.e (mod N); and (n) comparing X ref and X act .
Claim 18
Dependent Claim 24 words
A method according to claim 13 wherein S set is selected in accordance with a count value which is incremented for each Y calculation.
Claim 19
Dependent Claim 98 words
A method according to claim 14 wherein S set is determined by selecting a set S si of said factors S i , said selection being in accordance with a binary string V s =v si generated in said entity, and wherein Y is calculated according to the formula: ##EQU27## where the v ai values correspond to the bits of said n-bit binary string generated in said authentication device; wherein step (1) further comprises transmitting V s to said authentication device; and wherein, in step (m), the value of X ref is calculated according to the formula: ##EQU28##
Claim 20
Independent Claim 112 words
A system, including an entity for generating an output Y in response to an input v, said entity comprising: memory means having stored therein a modulus N which is the product of at least two prime numbers, and a set of n factors S i , i=1, . . . , n, where S i =F i d (mod N), wherein d is the secret key counterpart of a public key e associated with the modulus N, and F i , i=1, . . . , n, are n public factors, 0<F i <N; processing means adapted to compute ##EQU29## where v=v i is an n bit binary string; and input/output means.
Claim 21
Independent Claim 112 words
A system, including an entity for generating an output Y in response to an input v, said entity comprising: memory means having stored therein a modulus N which is the product of at least two prime numbers, and a set of n factors S i , i=1, . . . , n, where S i =F i d (mod N), wherein d is the secret key counterpart of a public key e associated with the modulus N, and F i , i=1, . . . , n, are n public factors, 0<F i <N; processing means adapted to compute ##EQU29## where v=v i is an n bit binary string; and input/output means.
Claim 22
Dependent Claim 31 words
A system according to claim 16, wherein the value of Y includes an additional factor S set which is dependent on a count value which is incremented for each Y calculation.
Claim 23
Dependent Claim 62 words
A system according to claim 17, wherein said memory means has stored therein an additional parity factor S p , and wherein said processing means is adapted to compute the value of Y by selectively including said additional parity factor S p in the expression for Y, such that the total members of factors included in the calculation of Y is even.
Claim 24
Dependent Claim 89 words
A system according to claim 16 wherein: said memory means has stored therein the value of said public key e; and said processing means is further adapted (a) to compute H=M e (mod N), where M is a message to be transmitted by said entity; (b) to convert H to a binary n bit vector v; and (c) to compute ##EQU30## using the bits v i of the computed vector v; and said input/output means is adapted to transmit Y as a message authentication code associated with said message.
Claim 25
Dependent Claim 79 words
A system according to claim 19, further including an authentication device which comprises: further input/output means; further memory means having stored therein said n public factors F i (i=1, . . . , n), said modulus N, and said public key e; and further processing means adapted to compute ##EQU31## (mod N); and X act =Y 3 (mod N) using the stored values of F i , N and e, and to compare X ref with X act .
Claim 26
Dependent Claim 36 words
A system according to claim 16, wherein said memory means has stored therein a public factor F ID unique to said entity, and a value S ID , where S ID =F ID d (mod N).
Claim 27
Dependent Claim 78 words
A system according to claim 21, further including an authentication device which comprises: further input/output means; further memory means having stored therein said n public factors F i 1 , . . . , n, said modulus N, and said public key e; and further processing means adapted to compute ##EQU32## and X act =Y e (mod N) using the stored values of F i , N and e, and to compare X ref with X act .
Claim 28
Dependent Claim 17 words
A system according to claim 22 wherein said further processing means is further adapted to compute ##EQU33##
Claim 29
Dependent Claim 78 words
A system according to claim 16, further including an authentication device which comprises: further input/output means; further memory means having stored therein said n public factors F i , i=1, . . . , n, said modulus N, and said public key e; and further processing means adapted to compute ##EQU34## and X act =Y e (mod N) using the stored values of F i , N and e, and to compare X ref with X act .
Claim 30
Dependent Claim 155 words
An entity comprising: memory means having stored therein (a) a modulus N which is the product of at least two prime numbers, (b) a set of n factors S i , i=1, . . . , n, where S i =F i .sup. (mod N), wherein d is the secret key counterpart of a public key e associated with the modulus N, and F i , i=1, . . . , n, are n public factors 0<F i <N, (c) said n public factors F i , i=1, . . . , n, (d) said modulus N, and (e) said public key e; processing means adapted to compute Y ##EQU35## where v=v i is an n bit binary string and further adapted to compute ##EQU36## and X act =Y e (mod N) using the stored values of F i , N and e, and to compare X ref with X act ; and input/output means.
Claim 31
Dependent Claim 155 words
An entity comprising: memory means having stored therein (a) a modulus N which is the product of at least two prime numbers, (b) a set of n factors S i , i=1, . . . , n, where S i =F i .sup. (mod N), wherein d is the secret key counterpart of a public key e associated with the modulus N, and F i , i=1, . . . , n, are n public factors 0<F i <N, (c) said n public factors F i , i=1, . . . , n, (d) said modulus N, and (e) said public key e; processing means adapted to compute Y ##EQU35## where v=v i is an n bit binary string and further adapted to compute ##EQU36## and X act =Y e (mod N) using the stored values of F i , N and e, and to compare X ref with X act ; and input/output means.
Claim 32
Dependent Claim 88 words
An entity according to claim 25 wherein: said memory means has stored therein the value of said public key e; said processing means is further adapted (a) to compute H=M e (mod N), where M is a message to be transmitted by said entity; (b) to convert H to a binary n bit vector v; and (c) to compute ##EQU37## using the bits v i of the computed vector v; and said input/output means is adapted to transmit Y as a message authentication code associated with said message.
Claim 33
Dependent Claim 36 words
An entity according to claim 26, wherein said memory means has stored therein a public factor F ID unique to said entity, and a value S ID , where S ID =F ID d (mod N).
Claim 34
Dependent Claim 16 words
An entity according to claim 27 wherein said processing means is further adapted to compute ##EQU38##
Claim 35
Dependent Claim 17 words
An entity according to claim 28 wherein said processing means is further adapted to compute ##EQU39## .

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7.5 Years (Year 8) 1997-06-18 1997-12-18 1998-06-19 $3760.00 Window Closed / Lapsed
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