Patent US5586186A successfully refreshed from Google Patents.
US5586186A
Expired / Lapsed
US
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Method and system for controlling unauthorized access to information distributed to users
Assignee: Microsoft Technology Licensing LLC
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Filing: 1994-07-15
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Granted: 1996-12-17
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Expires: 2014-07-15
Abstract
Abstract A system for controlling unauthorized access to information distributed to users and, more particularly, for controlling unauthorized access to software distributed to users is provided. One method utilizing the system of the present invention enables the software to be encrypted using a single encryption key and to be decrypted using a multiplicity of "decryption" keys, each of which is unique to a particular user. The "decryption" keys are the products of numeric representations of identifying information relating to users and unique user keys generated using the numeric representations and a "true" decryption key. Since each user receives a unique user key and both the numeric representation and the user key are generated using the identifying information, if the user reveals the numeric representation and the user key (or the product of the numeric representation and the user key), the numeric representation and the user key can be traced to the user who revealed them. Another method utilizing the system of the present invention introduces randomness or pseudo-randomness into the decryption scheme to provide an additional level of security to the scheme.
Inventors
- 👤 Gideon A. Yuval
- 👤 Michael Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:47
CPC Classifications
G; G06; G06F; G06F21/00; G06F21/10; H; H04; H04L; H04L9/00; H04L9/30; H04L9/3006; H04L9/302; G06F2211/00; G06F2211/007; G06F2221/00; G06F2221/21; G06F2221/2107; H04L2209/00; H04L2209/08; H04L2209/34; H04L2209/56
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
128 words
A method for controlling unauthorized access to information distributed to users, the method comprising the steps of: choosing an encryption parameter and generating from it an encryption key using a public key algorithm; generating a decryption key using the public key algorithm; encrypting the information using the encryption parameter and the encryption key; distributing identical copies of the encrypted form of the information to users; receiving identifying information from a user; generating a numeric representation of the identifying information; generating a unique user key using the numeric representation of the identifying information and decryption key information; providing the user with the unique user key; and decrypting the encrypted form of the information using the numeric representation of the identifying information, the unique user key, and the encryption parameter.
Claim 2
Independent Claim
128 words
A method for controlling unauthorized access to information distributed to users, the method comprising the steps of: choosing an encryption parameter and generating from it an encryption key using a public key algorithm; generating a decryption key using the public key algorithm; encrypting the information using the encryption parameter and the encryption key; distributing identical copies of the encrypted form of the information to users; receiving identifying information from a user; generating a numeric representation of the identifying information; generating a unique user key using the numeric representation of the identifying information and decryption key information; providing the user with the unique user key; and decrypting the encrypted form of the information using the numeric representation of the identifying information, the unique user key, and the encryption parameter.
Claim 3
Dependent Claim
112 words
The method of claim 1, wherein the step of generating an encryption key includes the step of generating the encryption key using an RSA algorithm, wherein the encryption parameter n is the product of any two prime numbers p and q, wherein φ(n)=(p-1)(q-1) and the encryption key e is relatively prime to φ(n); wherein the step of generating a decryption key includes the step of generating the decryption key using the RSA algorithm, wherein the decryption key d=e -1 (mod φ(n)); and wherein the step of encrypting the information includes the step of encrypting the information using the encryption function E(a)=a e mod n, wherein a is the information to be encrypted.
Claim 4
Dependent Claim
40 words
The method of claim 2, wherein the step of generating a unique user key includes the step of generating the unique user key y using the function y=d/x (mod φ(n)), wherein x is the numeric representation of the identifying information.
Claim 5
Dependent Claim
44 words
The method of claim 3, wherein the step of decrypting the encrypted form of the information includes the step of decrypting the encrypted form of the information using the decryption function D(c)=c xy mod n, wherein c is the encrypted form of the information.
Claim 6
Dependent Claim
14 words
The method of claim 1, wherein the decryption key information is the decryption key.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein the decryption key information is information from which the decryption key can be derived.
Claim 8
Dependent Claim
13 words
The method of claim 1, wherein the information distributed to users is software.
Claim 9
Dependent Claim
15 words
The method of claim 1, wherein the information distributed to users is stored on CD-ROM.
Claim 10
Dependent Claim
23 words
The method of claim 1, wherein the step of receiving identifying information includes the step of receiving unique identifying information from the user.
Claim 11
Dependent Claim
34 words
The method of claim 1, wherein the step of receiving identifying information includes the step of receiving a name, a credit card number, and an expiration date for a credit card from the user.
Claim 12
Dependent Claim
56 words
The method of claim 1, wherein the step of generating a numeric representation of the identifying information includes the step of generating the numeric representation such that the identifying information is uniquely determinable from the numeric representation and the numeric representation is uniquely determinable from the product of the numeric representation and the unique user key.
Claim 13
Dependent Claim
25 words
The method of claim 11, wherein the step of generating the numeric representation includes the step of encoding the identifying information using a Godel numbering.
Claim 14
Dependent Claim
26 words
The method of claim 12, wherein the step of generating the numeric representation further includes the step of encoding the identifying information using an error-correcting coding.
Claim 15
Dependent Claim
72 words
The method of claim 13, wherein the step of generating the numeric representation further includes the step of determining whether the numeric representation generated using the Godel numbering and the error-correcting coding is uniquely determinable from the product of the numeric representation and the unique user key and if not, modifying the identifying information and generating a numeric representation of the modified identifying information using the Godel numbering and the error-correcting coding.
Claim 16
Dependent Claim
44 words
The method of claim 14, wherein the steps of modifying the identifying information and generating a numeric representation of the modified identifying information are repeated until the numeric representation is uniquely determinable from the product of the numeric representation and the unique user key.
Claim 17
Independent Claim
115 words
A method for controlling unauthorized access to information stored on a storage medium, the method comprising the steps of: generating an encryption key using a public key algorithm; generating a decryption key using the public key algorithm; encrypting the information using the encryption key; storing the encrypted form of the information on the storage medium; receiving identifying information from a user; generating a numeric representation of the identifying information; generating a unique user key using the numeric representation of the identifying information and decryption key information; providing the user with the unique user key; and decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 18
Independent Claim
115 words
A method for controlling unauthorized access to information stored on a storage medium, the method comprising the steps of: generating an encryption key using a public key algorithm; generating a decryption key using the public key algorithm; encrypting the information using the encryption key; storing the encrypted form of the information on the storage medium; receiving identifying information from a user; generating a numeric representation of the identifying information; generating a unique user key using the numeric representation of the identifying information and decryption key information; providing the user with the unique user key; and decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 19
Independent Claim
169 words
A method for controlling unauthorized access to software stored on CD-ROM, the method comprising the steps of: selecting an encryption key e such that e is relatively prime to φ(n), wherein n is the product of any two prime numbers p and q and φ(n)=(p-1) (q-1); generating a decryption key d such that d=e -1 (mod φ(n)); encrypting the software using the encryption function E(a)=a e mod n, wherein a is the software to be encrypted; storing the encrypted form of the software on the CD-ROM; receiving identifying information from a user; generating a numeric representation of the identifying information by encoding the identifying information using a Godel numbering and an error-correcting coding; generating a unique user key y using the function y=d/x (mod φ(n)), wherein x is the numeric representation of the identifying information; providing the user with the unique user key y; and decrypting the encrypted form of the software using the decryption function D(c)=c xy mod n, wherein c is the encrypted form of the software.
Claim 20
Independent Claim
169 words
A method for controlling unauthorized access to software stored on CD-ROM, the method comprising the steps of: selecting an encryption key e such that e is relatively prime to φ(n), wherein n is the product of any two prime numbers p and q and φ(n)=(p-1) (q-1); generating a decryption key d such that d=e -1 (mod φ(n)); encrypting the software using the encryption function E(a)=a e mod n, wherein a is the software to be encrypted; storing the encrypted form of the software on the CD-ROM; receiving identifying information from a user; generating a numeric representation of the identifying information by encoding the identifying information using a Godel numbering and an error-correcting coding; generating a unique user key y using the function y=d/x (mod φ(n)), wherein x is the numeric representation of the identifying information; providing the user with the unique user key y; and decrypting the encrypted form of the software using the decryption function D(c)=c xy mod n, wherein c is the encrypted form of the software.
Claim 21
Independent Claim
74 words
A method for generating a unique user key that can be used together with a numeric representation of identifying information relating to a user to decrypt information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; generating a numeric representation of the identifying information; and generating a unique user key using the numeric representation of the identifying information and decryption key information.
Claim 22
Independent Claim
74 words
A method for generating a unique user key that can be used together with a numeric representation of identifying information relating to a user to decrypt information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; generating a numeric representation of the identifying information; and generating a unique user key using the numeric representation of the identifying information and decryption key information.
Claim 23
Independent Claim
82 words
A method for decrypting information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; receiving a unique user key from the user, the unique user key having been generated using a numeric representation of the identifying information and decryption key information; generating the numeric representation of the identifying information; and decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 24
Independent Claim
82 words
A method for decrypting information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; receiving a unique user key from the user, the unique user key having been generated using a numeric representation of the identifying information and decryption key information; generating the numeric representation of the identifying information; and decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 25
Independent Claim
102 words
A system for controlling unauthorized access to information distributed to users, the system comprising: an encryptor for generating an encryption key and a decryption key using a public key algorithm and for encrypting the information using the encryption key; a user key generator for receiving identifying information from a user, for generating a numeric representation of the identifying information, and for generating a unique user key using the numeric representation of the identifying information and decryption key information; and a decryptor for decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 26
Independent Claim
102 words
A system for controlling unauthorized access to information distributed to users, the system comprising: an encryptor for generating an encryption key and a decryption key using a public key algorithm and for encrypting the information using the encryption key; a user key generator for receiving identifying information from a user, for generating a numeric representation of the identifying information, and for generating a unique user key using the numeric representation of the identifying information and decryption key information; and a decryptor for decrypting the encrypted form of the information using the numeric representation of the identifying information and the unique user key.
Claim 27
Independent Claim
133 words
A method for controlling unauthorized access to information distributed to users, the method comprising the steps of: generating two encryption keys using a public key algorithm; generating two decryption keys using the public key algorithm; encrypting the information twice using the two encryption keys; distributing the two encrypted forms of the information to users; receiving identifying information from a user; generating two numeric representations of the identifying information; generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; providing the user with the two unique user keys; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 28
Independent Claim
133 words
A method for controlling unauthorized access to information distributed to users, the method comprising the steps of: generating two encryption keys using a public key algorithm; generating two decryption keys using the public key algorithm; encrypting the information twice using the two encryption keys; distributing the two encrypted forms of the information to users; receiving identifying information from a user; generating two numeric representations of the identifying information; generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; providing the user with the two unique user keys; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 29
Dependent Claim
122 words
The method of claim 21, wherein the step of generating two encryption keys includes the step of generating the two encryption keys using an RSA algorithm, wherein the encryption keys e and e' are relatively prime to φ(n), n is the product of any two prime numbers p and q, and φ(n)=(p-1) (q-1); wherein the step of generating two decryption keys includes the step of generating the two decryption keys using the RSA algorithm, wherein d=e -1 (mod φ(n)) and d'=e' -1 (mod φ(n)); and wherein the step of encrypting the information twice includes the step of encrypting the information twice using the encryption functions E(a)=a e mod n and E'(a)=a e' mod n, wherein a is the information to be encrypted.
Claim 30
Dependent Claim
71 words
The method of claim 22, wherein the step of generating two unique user keys includes the steps of: selecting the random number r, wherein r ε Z.sub.φ(n) and Z.sub.φ(n) is equal to the set of numbers from 0 to (φ(n)-1); and generating two unique user keys y and y' using the functions y=rd/x (mod =(n)) and y'=(1-r)d'/x' (mod φ(n)), wherein x and x' are the numeric representations of the identifying information.
Claim 31
Dependent Claim
54 words
The method of claim 23, wherein the step of decrypting the two encrypted forms of the information includes the step of decrypting the two encrypted forms of the information using the decryption functions D(c)=c xy mod n and D'(c')=c' x'y' mod n, wherein c and c' are the two encrypted forms of the information.
Claim 32
Dependent Claim
15 words
The method of claim 21, wherein the decryption key information is the two decryption keys.
Claim 33
Dependent Claim
21 words
The method of claim 21, wherein the decryption key information is information from which the two decryption keys can be derived.
Claim 34
Dependent Claim
13 words
The method of claim 21, wherein the information distributed to users is software.
Claim 35
Dependent Claim
15 words
The method of claim 21, wherein the information distributed to users is stored on CD-ROM.
Claim 36
Dependent Claim
23 words
The method of claim 21, wherein the step of receiving identifying information includes the step of receiving unique identifying information from the user.
Claim 37
Dependent Claim
34 words
The method of claim 21, wherein the step of receiving identifying information includes the step of receiving a name, a credit card number, and an expiration date for a credit card from the user.
Claim 38
Dependent Claim
57 words
The method of claim 21, wherein the step of generating two numeric representations includes the step of generating the two numeric representations such that the identifying information is uniquely determinable from the two numeric representations and the two numeric representations are uniquely determinable from the products of the two numeric representations and the two unique user keys.
Claim 39
Dependent Claim
28 words
The method of claim 31, wherein the step of generating the two numeric representations further includes the step of encoding the identifying information twice using a Godel numbering.
Claim 40
Dependent Claim
28 words
The method of claim 32, wherein the step of generating the two numeric representations further includes the step of encoding the identifying information twice using an error-correcting coding.
Claim 41
Dependent Claim
76 words
The method of claim 33, wherein the step of generating the two numeric representations further includes the step of determining whether the two numeric representations generated using the Godel numbering and the error-correcting coding are uniquely determinable from the products of the two numeric representations and the two unique user keys and if not, modifying the identifying information and generating two numeric representations of the modified identifying information using the Godel numbering and the error-correcting coding.
Claim 42
Dependent Claim
47 words
The method of claim 34, wherein the steps of modifying the identifying information and generating two numeric representations of the modified identifying information are repeated until the two numeric representations are uniquely determinable from the products of the two numeric representations and the two unique user keys.
Claim 43
Independent Claim
137 words
A method for controlling unauthorized access to information stored on a storage medium, the method comprising the steps of: generating two encryption keys using a public key algorithm; generating two decryption keys using the public key algorithm; encrypting the information twice using the two encryption keys; storing the two encrypted forms of the information on the storage medium; receiving identifying information from a user; generating two numeric representations of the identifying information; generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; providing the user with the two unique user keys; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 44
Independent Claim
137 words
A method for controlling unauthorized access to information stored on a storage medium, the method comprising the steps of: generating two encryption keys using a public key algorithm; generating two decryption keys using the public key algorithm; encrypting the information twice using the two encryption keys; storing the two encrypted forms of the information on the storage medium; receiving identifying information from a user; generating two numeric representations of the identifying information; generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; providing the user with the two unique user keys; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 45
Independent Claim
240 words
A method for controlling unauthorized access to software stored on CD-ROM, the method comprising the steps of: selecting two encryption keys e and e' such that e and e' are relatively prime to φ(n), wherein n is the product of any two prime numbers p and q and φ(n)=(p-1) (q-1); generating two decryption keys d and d' such that d=e -1 (mod φ(n)) and d'=e' -1 (mod φ(n)); encrypting the software twice using the encryption functions E(a)=a e mod n and E'(a)=a e' mod n, wherein a is the software to be encrypted; storing the two encrypted forms of the software on the CD-ROM; receiving identifying information from a user; generating two numeric representations of the identifying information by modifying the identifying information and encoding the identifying information and the modified identifying information using a Godel numbering and an error-correcting coding; selecting a random number r, wherein r ε Z.sub.φ(n) and Z.sub.φ(n) is equal to the set of numbers from 0 to (φ(n)-1); generating two unique user keys using the functions y=rd/x (mod φ(n)) and y'=(1-r)d'/x' (mod φ(n)), wherein x and x' are the numeric representations of the identifying information and the modified identifying information; decrypting the two encrypted forms of the software using the decryption functions D(c)=c d mod n and D'(c')=c' d' mod n, wherein c and c' are the two encrypted forms of the software; and multiplying the results of the two decryptions to recover the software.
Claim 46
Independent Claim
240 words
A method for controlling unauthorized access to software stored on CD-ROM, the method comprising the steps of: selecting two encryption keys e and e' such that e and e' are relatively prime to φ(n), wherein n is the product of any two prime numbers p and q and φ(n)=(p-1) (q-1); generating two decryption keys d and d' such that d=e -1 (mod φ(n)) and d'=e' -1 (mod φ(n)); encrypting the software twice using the encryption functions E(a)=a e mod n and E'(a)=a e' mod n, wherein a is the software to be encrypted; storing the two encrypted forms of the software on the CD-ROM; receiving identifying information from a user; generating two numeric representations of the identifying information by modifying the identifying information and encoding the identifying information and the modified identifying information using a Godel numbering and an error-correcting coding; selecting a random number r, wherein r ε Z.sub.φ(n) and Z.sub.φ(n) is equal to the set of numbers from 0 to (φ(n)-1); generating two unique user keys using the functions y=rd/x (mod φ(n)) and y'=(1-r)d'/x' (mod φ(n)), wherein x and x' are the numeric representations of the identifying information and the modified identifying information; decrypting the two encrypted forms of the software using the decryption functions D(c)=c d mod n and D'(c')=c' d' mod n, wherein c and c' are the two encrypted forms of the software; and multiplying the results of the two decryptions to recover the software.
Claim 47
Independent Claim
97 words
A method for decrypting information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; receiving two unique user keys from the user, the unique user keys having been generated using two numeric representations of the identifying information and decryption key information; generating the two numeric representations of the identifying information; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 48
Independent Claim
97 words
A method for decrypting information that has been encrypted using a public key algorithm, the method comprising the steps of: receiving identifying information from a user; receiving two unique user keys from the user, the unique user keys having been generated using two numeric representations of the identifying information and decryption key information; generating the two numeric representations of the identifying information; decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys; and multiplying the results of the two decryptions to recover the information.
Claim 49
Independent Claim
123 words
A system for controlling unauthorized access to information distributed to users, the system comprising: an encryptor for generating two encryption keys and two decryption keys using a public key algorithm and for encrypting the information twice using the two encryption keys; a user key generator for receiving identifying information from a user, for generating two numeric representations of the identifying information, and for generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; and a decryptor for decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys and multiplying the results of the two decryptions to recover the information.
Claim 50
Independent Claim
123 words
A system for controlling unauthorized access to information distributed to users, the system comprising: an encryptor for generating two encryption keys and two decryption keys using a public key algorithm and for encrypting the information twice using the two encryption keys; a user key generator for receiving identifying information from a user, for generating two numeric representations of the identifying information, and for generating two unique user keys using the two numeric representations of the identifying information, decryption key information, and a random number; and a decryptor for decrypting the two encrypted forms of the information using the two numeric representations of the identifying information and the two unique user keys and multiplying the results of the two decryptions to recover the information.
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USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1999-12-17 | 2000-06-17 | 2000-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-17 | 2004-06-17 | 2004-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-17 | 2008-06-17 | 2008-12-17 | $7700.00 | Window Closed / Lapsed |