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公开(公告)号：JPH1041932A
公开(公告)日：1998-02-13
申请号：JP7150097
申请日：1997-03-25
Applicant: IBM
Inventor： JOHNSON DONALD B , KARGER PAUL A , KAUFMAN CHARLES W JR , MATYAS STEPHEN M JR , YUNG MARCEL M , ZUNIC NEVENKO
Abstract: PROBLEM TO BE SOLVED: To provide the key recovery system handling requests in contention of different entities by several persons by using each of a plurality of of common share keys with respect to a plurality of key recovery agents. SOLUTION: A PQR value 102 to consent to a secret value 102 referred to as a PQR for mutual communication is made up of P, Q values 104, 106 in m-bit and an R value 108 in m-bit. The P value 104 is used in common for a 1st key recovery agent of each country and the Q value 106 is used in common by a 2nd key recovery agent. The R value 108 is used in common between users. In order to generate a cryptographic key, the P value 104 and the Q value 106 are processed by an exclusive OR (XOR) and a resulting value (112) in 112-bits is generated. Then the resulting value 112 is linked with the R value 108 to generate an intermediate value 114 in 168 bits. The intermediate value 114 is hash-processed (116) and a final key value 118 is extracted.
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公开(公告)号：CA2197915C
公开(公告)日：2002-12-10
申请号：CA2197915
申请日：1997-02-05
Applicant: IBM
Inventor： JOHNSON DONALD B , KARGER PAUL A , KAUFMAN CHARLES W JR , MATYAS STEPHEN M JR , YUNG MARCEL M , ZUNIC NEVENKO
Abstract: A cryptographic key recovery system for generating a cryptographic key for use by a pair of communicating parties while simultaneously providing fo r its recovery using one or more key recover agents. A plurality of m-bit shared k ey parts (P, Q) are generated which are shared with respective key recovery agents, while an n-bit nonshared key part (R) is generated that is not share d with any key recovery agent. The shared key parts (P, Q) are combined to generate an m-bit value which is concatenated with the nonshared key part (R ) to generate an (m + n)-bit value from which an encryption key is generated. The cryptographic system has the effective work factor of an n-bit key to al l of the key recovery agents acting in concert, but has the effective work fac tor of an (m + n)-bit to any other combination of third parties. The quantity n is selected to make authorized key recovery feasible, but not so trivial as to permit routine decryption of intercepted communications, while the quantity m is selected to make decryption by unauthorized third parties infeasible. Means are provided for verifying that the shared key parts have been shared with the k ey recovery agents before permitting encrypted communications using the thus generated key.
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Patent Agency Ranking
公开(公告)号：PL331313A1
公开(公告)日：1999-07-05
申请号：PL33131397
申请日：1997-07-23
Applicant: IBM
Inventor： JOHNSON DONALD BYRON , KARGER PAUL ASHLEY , KAUFMAN CHARLES WILLIAM JR , MATYAS STEPHEN MICHAEL JR , SAFFORD DAVID ROBERT , YUNG MARCEL MORDECHAY , ZUNIC NEVENKO
Abstract: The method for providing for recovery of a cryptographic key using a number of cooperating key recovery agents comprises generating a number of shared key recovery values such that the key may be regenerated from the shared key recovery values without requiring additional non-public information. The shared recovery values are made available to the key recovery agents to enable recovery of the key. A pair of communicating parties use the cryptographic key to communicate, and the key is set by one party and sent to the ther one. Alternatively the key may be set by both parties acting together.
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公开(公告)号：DE69706867D1
公开(公告)日：2001-10-25
申请号：DE69706867
申请日：1997-07-23
Applicant: IBM
Inventor： JOHNSON BYRON , KARGER ASHLEY , KAUFMAN WILLIAM , MATYAS MICHAEL , SAFFORD ROBERT , YUNG MORDECHAY , ZUNIC NEVENKO
Abstract: The method for providing for recovery of a cryptographic key using a number of cooperating key recovery agents comprises generating a number of shared key recovery values such that the key may be regenerated from the shared key recovery values without requiring additional non-public information. The shared recovery values are made available to the key recovery agents to enable recovery of the key. A pair of communicating parties use the cryptographic key to communicate, and the key is set by one party and sent to the ther one. Alternatively the key may be set by both parties acting together.
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公开(公告)号：CA2197915A1
公开(公告)日：1997-10-11
申请号：CA2197915
申请日：1997-02-05
Applicant: IBM
Inventor： JOHNSON DONALD B , KARGER PAUL A , KAUFMAN CHARLES W JR , MATYAS STEPHEN M JR , YUNG MARCEL M , ZUNIC NEVENKO
Abstract: A cryptographic key recovery system for generating a cryptographic key for use by a pair of communicating parties while simultaneously providing for its recovery using one or more key recover agents. A plurality of m-bit shared key parts (P, Q) are generated which are shared with respective key recovery agents, while an n-bit nonshared key part (R) is generated that is not shared with any key recovery agent. The shared key parts (P, Q) are combined to generate an m-bit value which is concatenated with the nonshared key part (R) to generate an (m + n)-bit value from which an encryption key is generated. The cryptographic system has the effective work factor of an n-bit key to all of the key recovery agents acting in concert, but has the effective work factor of an (m + n)-bit to any other combination of third parties. The quantity n is selected to make authorized key recovery feasible, but not so trivial as to permit routine decryption of intercepted communications, while the quantity m is selected to make decryption by unauthorized third parties infeasible. Means are provided for verifying that the shared key parts have been shared with the key recovery agents before permitting encrypted communications using the thus generated key.
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公开(公告)号：HU225077B1
公开(公告)日：2006-06-28
申请号：HU9902892
申请日：1997-07-23
Applicant: IBM
Inventor： JOHNSON DONALD BYRON , KARGER PAUL ASHLEY , KAUFMAN CHARLES WILLIAM JR , MATYAS STEPHEN MICHAEL JR , SAFFORD DAVID ROBERT , YUNG MARCEL MORDECHAY , ZUNIC NEVENKO
Abstract: The method for providing for recovery of a cryptographic key using a number of cooperating key recovery agents comprises generating a number of shared key recovery values such that the key may be regenerated from the shared key recovery values without requiring additional non-public information. The shared recovery values are made available to the key recovery agents to enable recovery of the key. A pair of communicating parties use the cryptographic key to communicate, and the key is set by one party and sent to the ther one. Alternatively the key may be set by both parties acting together.
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公开(公告)号：DE69706867T2
公开(公告)日：2002-04-11
申请号：DE69706867
申请日：1997-07-23
Applicant: IBM
Inventor： JOHNSON BYRON , KARGER ASHLEY , KAUFMAN WILLIAM , MATYAS MICHAEL , SAFFORD ROBERT , YUNG MORDECHAY , ZUNIC NEVENKO
Abstract: The method for providing for recovery of a cryptographic key using a number of cooperating key recovery agents comprises generating a number of shared key recovery values such that the key may be regenerated from the shared key recovery values without requiring additional non-public information. The shared recovery values are made available to the key recovery agents to enable recovery of the key. A pair of communicating parties use the cryptographic key to communicate, and the key is set by one party and sent to the ther one. Alternatively the key may be set by both parties acting together.
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