US6038322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Group key distribution
Assignee: Cisco Technology Inc
•
Filing: 1998-10-20
•
Granted: 2000-03-14
•
Expires: 2018-10-20
Abstract
Abstract A method for distributing a secret key from a key holder H to intended group members M. The method assumes that during the distribution process each party, a group member M and the key holder H, can decrypt and encrypt exchanged information such that the encrypter knows that the decrypter will be the intended party. The method preferably uses a public key/private key encryption technique in which, for example, a trusted Certificate Authority in a public key infrastructure signs the certificates to provide the public keys involved in the encryption. Alternatively, the method, together with a symmetric cipher, uses a shared secret, established in an authenticated mechanism that is outside the information exchanges of the invention. Additionally, the method uses a strong mixing function that takes several items of data as input and produces a pseudo-random authentication (or digest). Inputs to the mixing function include identity stamps that are generated by each member M and key holder H. These inputs can be the identity of the stamp generator, such as a network address, port, or protocol, a timestamp, and/or a secret value that is known only to the stamp generator. The stamps include information to bind member M if generated by key holder H, and to bind key holder H if generated by member M. Consequently, the invention authenticates each communication exchange between member M and key holder H.
Inventors
- 👤 Dan Harkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:22
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/08; H04L9/0816; H04L9/0819; H04L9/0825; H04L63/00; H04L63/04; H04L63/0428; H04L63/0442; H04L63/06; H04L63/065; H04L63/08; H04L63/0823; H04L9/083; H04L9/0833; H04L9/32; H04L9/3247
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
178 words
A method for distributing a secret key K from a key holder to a group member, comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member providing said encrypted code R me and an authentication-M to said key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder encrypting said code R h to form an encrypted code R he ; the key holder providing said code R he and an authentication-H to the group member; the group member decrypting said encrypted code R he to acquire said code R h ; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 2
Independent Claim
178 words
A method for distributing a secret key K from a key holder to a group member, comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member providing said encrypted code R me and an authentication-M to said key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder encrypting said code R h to form an encrypted code R he ; the key holder providing said code R he and an authentication-H to the group member; the group member decrypting said encrypted code R he to acquire said code R h ; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 3
Dependent Claim
31 words
The method of claim 1 comprising the further steps of: the group member providing a Request to the key holder; and the key holder providing an Authorization to the group member.
Claim 4
Dependent Claim
42 words
The method of claim 1 wherein said step of the group member providing said authentication-M comprises the steps of: the group member signing said authentication-M to form a signature S m ; and the key holder verifying said signature S m .
Claim 5
Dependent Claim
42 words
The method of claim 3 wherein said step of the key holder providing said authentication-H comprises the steps of: the key holder signing said authentication-H to form a signature S h ; and the group member verifying said signature S h .
Claim 6
Dependent Claim
53 words
The method of claim 1 wherein said step of the group member encrypting said code R m uses a public key K ph associated with said key holder, and said step of the key holder decrypting said encrypted code R me uses a private key associated with said public key K ph .
Claim 7
Dependent Claim
53 words
The method of claim 5 wherein said step of the key holder encrypting said code R h uses a public key K pm associated with the group member, and said step of the group member decrypting said encrypted code R he uses a private key associated with said public key K pm .
Claim 8
Dependent Claim
19 words
The method of claim 6 wherein said authentication-M results from a mixing function of at least one authentication-M input.
Claim 9
Dependent Claim
43 words
The method of claim 7 comprising the further steps of: the key holder providing a stamp C h to the group member; said authentication-M including said stamp C h as an input; and the key holder H verifying said stamp C h .
Claim 10
Dependent Claim
33 words
The method of claim 8 wherein said stamp C h results from a mixing function of an identity of the group member, a timestamp, and a secret known only to the key holder.
Claim 11
Dependent Claim
19 words
The method of claim 9 wherein said authentication-H results from a mixing function of at least one authentication-H input.
Claim 12
Dependent Claim
46 words
The method of claim 10 comprising the further steps of: the group member providing a stamp C m to the key holder; said authentication-H including said stamp C m and said code R m as inputs; and the group member verifying said stamp C m .
Claim 13
Dependent Claim
29 words
The method of claim 11 wherein said stamp C m comprises an identity of the key holder H, a timestamp, and a secret known only to the group member.
Claim 14
Dependent Claim
16 words
The method of claim 12 wherein said code R m and said key K are numbers.
Claim 15
Dependent Claim
33 words
The method of claim 13 wherein said step of the key holder using said secret key K and said step of the group member deriving said secret key K use an exclusive-OR function.
Claim 16
Dependent Claim
42 words
The method of claim 14 wherein said step of the group member providing said authentication-M comprises the steps of: the group member signing said authentication-M to form a signature S m ; and the key holder verifying said signature S m .
Claim 17
Dependent Claim
42 words
The method of claim 15 wherein said step of the key holder providing said authentication-H comprises the steps of: the key holder signing said authentication-H to form a signature S h ; and the group member verifying said signature S h .
Claim 18
Dependent Claim
30 words
The method of claim 16 comprising the further steps of: group member providing a Request to the key holder; and the key holder providing an Authorization to the group member.
Claim 19
Dependent Claim
28 words
The method of claim 14 wherein said authentication-M further includes as inputs said code R m , said stamp C m and said identity of the group member.
Claim 20
Dependent Claim
35 words
The method of claim 18 wherein said authentication-H further includes as inputs said stamp C h , said code R h , said identity of the group member, and said identity of the key holder.
Claim 21
Dependent Claim
45 words
The method of claim 19 wherein said step of the group member providing said authentication-M to the key holder comprises the steps of: group member signing said authentication-M to form a signature S m ; and the key holder verifying said signature S m .
Claim 22
Dependent Claim
46 words
The method of claim 20 wherein said step of the key holder providing said authentication-H to the group member comprises the steps of: the key holder signing said authentication-H to form a signature S h ; and the group member verifying said signature S h .
Claim 23
Dependent Claim
31 words
The method of claim 21 comprising the further steps of: the group member providing a Request to the key holder; and the key holder providing an Authorization to the group member.
Claim 24
Independent Claim
166 words
A method for distributing a secret key K from a key holder to a group member, comprising the steps of: the group member encrypting a code R m to form an encrypted code R m ; the group member signing an authentication-M to form a signature S m ; the group member providing said encrypted code R me and said signature S m to the key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said signature S m and said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder providing said code R h and an authentication-H to the group member; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 25
Independent Claim
166 words
A method for distributing a secret key K from a key holder to a group member, comprising the steps of: the group member encrypting a code R m to form an encrypted code R m ; the group member signing an authentication-M to form a signature S m ; the group member providing said encrypted code R me and said signature S m to the key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said signature S m and said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder providing said code R h and an authentication-H to the group member; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 26
Dependent Claim
53 words
The method of claim 23 wherein said step of the group member encrypting said code R m uses a public key K ph associated with said key holder, and said step of the key holder decrypting said encrypted code R me uses a private key associated with said public key K ph .
Claim 27
Dependent Claim
19 words
The method of claim 24 wherein said authentication-M results from a mixing function of at least one authentication-M input.
Claim 28
Dependent Claim
47 words
The method of claim 25 comprising the further steps of: the key holder providing a stamp C h to said group member; said authentication-M including said stamp C h and said code R m as inputs; and the key holder H verifying said stamp C h .
Claim 29
Dependent Claim
33 words
The method of claim 26 wherein said stamp C h results from a mixing function of an identity of the group member, a timestamp, and a secret known only to the key holder.
Claim 30
Dependent Claim
19 words
The method of claim 27 wherein said authentication-H results from a mixing function of at least one authentication-H input.
Claim 31
Dependent Claim
46 words
The method of claim 28 comprising the further steps of: the group member providing a stamp C m to the key holder; said authentication-H including said stamp C m and said code R m as inputs; and the group member verifying said stamp C m .
Claim 32
Dependent Claim
33 words
The method of claim 29 wherein said stamp C m results from a mixing function of an identity of the key holder, a timestamp, and a secret known only to the group member.
Claim 33
Dependent Claim
16 words
The method of claim 30 wherein said code R m and said key K are numbers.
Claim 34
Dependent Claim
33 words
The method of claim 31 wherein said step of the key holder using said secret key K and said step of the group member deriving said secret key K use an exclusive-OR function.
Claim 35
Dependent Claim
31 words
The method of claim 32 comprising the further steps of: the group member providing a Request to the key holder; and the key holder providing an Authorization to the group member.
Claim 36
Dependent Claim
23 words
The method of claim 33 wherein said authentication-M further includes as inputs said stamp C m and said identity of the group member.
Claim 37
Dependent Claim
36 words
The method of claim 34 wherein said authentication-H further includes as inputs said stamp C h , said code R h , said identity of group member M, and said identity of the key holder H.
Claim 38
Dependent Claim
190 words
A computer-readable medium embodying instructions for causing a device to perform a distribution of a secret key K from a key holder to a group member, said distribution comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member providing said encrypted code R me and an authentication-M to said key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder encrypting said code R h to form an encrypted code R he ; the key holder providing said code R he and an authentication-H to the group member; the group member decrypting said encrypted code R he to acquire said code R h ; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 39
Dependent Claim
190 words
A computer-readable medium embodying instructions for causing a device to perform a distribution of a secret key K from a key holder to a group member, said distribution comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member providing said encrypted code R me and an authentication-M to said key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder encrypting said code R h to form an encrypted code R he ; the key holder providing said code R he and an authentication-H to the group member; the group member decrypting said encrypted code R he to acquire said code R h ; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 40
Dependent Claim
44 words
The computer-readable medium of claim 36 wherein the step of the group member providing said authentication-M comprises the steps of: the group member signing the said authentication-M to form a signature S m ; and the key holder verifying said signature S m .
Claim 41
Dependent Claim
43 words
The computer-readable medium of claim 37 wherein the step of the key holder providing said authentication-H comprises the steps of: the key holder signing said authentication-H to form a signature S h ; and the group member verifying said signature S h .
Claim 42
Dependent Claim
208 words
A computer system for distributing a secret key K from a key holder to a group member, comprising: means for the group member to encrypt a code R m to form an encrypted code R me ; means for the group member to provide said encrypted code R me , and an authentication-M to said key holder; means for the key holder to decrypt said encrypted code R me to acquire said code R m ; means for the key holder to verify said authentication-M; means for the key holder to use said secret key K and said code R m as inputs to a reversible function to generate a code R h ; means for the key holder to encrypt said code R h to form an encrypted code R he ; means for the key holder to provide said code R he , and an authentication-H to the group member; means for the group member to decrypt said encrypted code R he to acquire said code R h ; means for the group member to verify said authentication-H; and means for the group member to derive said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 43
Dependent Claim
208 words
A computer system for distributing a secret key K from a key holder to a group member, comprising: means for the group member to encrypt a code R m to form an encrypted code R me ; means for the group member to provide said encrypted code R me , and an authentication-M to said key holder; means for the key holder to decrypt said encrypted code R me to acquire said code R m ; means for the key holder to verify said authentication-M; means for the key holder to use said secret key K and said code R m as inputs to a reversible function to generate a code R h ; means for the key holder to encrypt said code R h to form an encrypted code R he ; means for the key holder to provide said code R he , and an authentication-H to the group member; means for the group member to decrypt said encrypted code R he to acquire said code R h ; means for the group member to verify said authentication-H; and means for the group member to derive said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 44
Dependent Claim
46 words
The computer system of claim 39 wherein means for the group member to provide said authentication-M comprises: means for the group member to sign said authentication-M to form a signature S m ; and means for the key holder to verify said signature S m .
Claim 45
Dependent Claim
46 words
The computer system of claim 40 wherein means for the key holder to provide said authentication-H comprises: means for they key holder to sign said authentication-H to form a signature S h ; and means for the group member to verify said signature S h .
Claim 46
Dependent Claim
178 words
A computer-readable medium embodying instructions for causing a device to perform a distribution of a secret key K from a key holder to a group member, said distribution comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member signing an authentication-M to form a signature S m ; the group member providing said encrypted code R me and said signature S m to the key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said signature S m and said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder providing said code R h and an authentication-H to the group member; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 47
Dependent Claim
178 words
A computer-readable medium embodying instructions for causing a device to perform a distribution of a secret key K from a key holder to a group member, said distribution comprising the steps of: the group member encrypting a code R m to form an encrypted code R me ; the group member signing an authentication-M to form a signature S m ; the group member providing said encrypted code R me and said signature S m to the key holder; the key holder decrypting said encrypted code R me to acquire said code R m ; the key holder verifying said signature S m and said authentication-M; the key holder using said secret key K and said code R m as inputs to a reversible function to generate a code R h ; the key holder providing said code R h and an authentication-H to the group member; the group member verifying said authentication-H; and the group member deriving said secret key K having said code R h and said code R m as inputs to the reversible function.
Claim 48
Dependent Claim
43 words
The computer-readable medium of claim 42 wherein the step of the key holder providing said authentication-H comprises the steps of: the key holder signing said authentication-H to form a signature S h ; and the group member verifying said signature S h .
Claim 49
Dependent Claim
190 words
A computer system for distributing a secret key K from a key holder to a group member, comprising: means for the group member to encrypt a code R m to form an encrypted code R me ; means for the group member to sign an authentication-M to form a signature S m ; means for the group member to provide said encrypted code R me and said signature S m to the key holder; means for the key holder to decrypt said encrypted code R me to acquire said code R m ; means for the key holder to verify said signature S m and said authentication-M; means for the key holder to use said secret key K and said code R m as inputs to a reversible function to generate a code R h ; means for the key holder to provide said code R h and an authentication-H to the group member; means for the group member to verify said authentication-H; and means for the group member to derive said secret key K having said number R h and said R m as inputs to the reversible function.
Claim 50
Dependent Claim
190 words
A computer system for distributing a secret key K from a key holder to a group member, comprising: means for the group member to encrypt a code R m to form an encrypted code R me ; means for the group member to sign an authentication-M to form a signature S m ; means for the group member to provide said encrypted code R me and said signature S m to the key holder; means for the key holder to decrypt said encrypted code R me to acquire said code R m ; means for the key holder to verify said signature S m and said authentication-M; means for the key holder to use said secret key K and said code R m as inputs to a reversible function to generate a code R h ; means for the key holder to provide said code R h and an authentication-H to the group member; means for the group member to verify said authentication-H; and means for the group member to derive said secret key K having said number R h and said R m as inputs to the reversible function.
Claim 51
Dependent Claim
46 words
The computer system of claim 44 wherein means for the key holder to provide said authentication-H comprises: means for the key holder to sign said authentication-H to form a signature S h ; and means for the group member to verify said signature S h .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-14 | 2003-09-13 | 2004-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-14 | 2007-09-13 | 2008-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-14 | 2011-09-13 | 2012-03-14 | $7700.00 | Window Closed / Lapsed |