Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
90 words
A method of generating a cryptographic key for use by a pair of communicating parties while providing for the recovery of said key using a plurality of cooperating key recovery agents, said method comprising the steps of: generating a plurality of shared key parts that are shared with respective key recovery agents; generating said key as a function of said shared key parts; and making respective ones of said shared key parts available to said key recovery agents to facilitate said recovery of said key using said key recovery agents.
Claim 2
Dependent Claim
40 words
The method of claim 1 in which said step of generating said key comprises the step of: combining said shared key parts to generate a composite key part; and generating said key as a function of said composite key part.
Claim 3
Dependent Claim
20 words
The method of claim 2 in which said shared key parts and said composite key part have a common length.
Claim 4
Dependent Claim
19 words
The method of claim 2 or 3 in which said shared key parts are combined by modulo 2 addition.
Claim 5
Independent Claim
87 words
The method of any preceding claim in which each of said key recovery agents has a public encryption key and a corresponding private decryption key, said step of making respective ones of said shared key parts available to said key recovery agents comprising the steps of: encrypting said shared key parts using the public encryption keys of said key recovery agents to generate a plurality of encrypted shared key parts; and transmitting said encrypted shared key parts over a communications channel accessible to said key recovery agents.
Claim 6
Independent Claim
43 words
The method of any preceding claim, further comprising the step of generating a nonshared key part that is not shared with any key recovery agent, said cryptographic key being generated as a function of said shared key parts and said nonshared key part.
Claim 7
Dependent Claim
54 words
The method of claim 6 in which said step of generating said key comprises the step of: combining said shared key parts to generate a composite key part; concatenating said composite key part with said nonshared key part to generate a resultant value; and generating said key as a function of said resultant value.
Claim 8
Dependent Claim
92 words
Apparatus for generating a cryptographic key for use by a pair of communicating parties while providing for the recovery of said key using a plurality of cooperating key recovery agents, said apparatus comprising: means for generating a plurality of shared key parts that are shared with respective key recovery agents; means for generating said key as a function of said shared key parts; and means for making respective ones of said shared key parts available to said key recovery agents to facilitate said recovery of said key using said key recovery agents.
Claim 9
Dependent Claim
40 words
The apparatus of claim 8 in which means for generating said key comprises: means for combining said shared key parts to generate a composite key part; and means for generating said key as a function of said composite key part.
Claim 10
Dependent Claim
20 words
The apparatus of claim 9 in which said shared key parts and said composite key part have a common length.
Claim 11
Dependent Claim
19 words
The apparatus of claim 9 or 10 in which said shared key parts are combined by modulo 2 addition.
Claim 12
Independent Claim
90 words
The apparatus of any of claims 8-11 in which each of said key recovery agents has a public encryption key and a corresponding private decryption key, wherein said means for making respective ones of said shared key parts available to said key recovery agents comprises: means for encrypting said shared key parts using the public encryption keys of said key recovery agents to generate a plurality of encrypted shared key parts; and means for transmitting said encrypted shared key parts over a communications channel accessible to said key recovery agents.
Claim 13
Independent Claim
43 words
The apparatus of any of claims 8-12, further comprising means for generating a nonshared key part that is not shared with any key recovery agent, said cryptographic key being generated as a function of said shared key parts and said nonshared key part.
Claim 14
Dependent Claim
57 words
The apparatus of claim 13 in which said means for generating said key comprises: means for combining said shared key parts to generate a composite key part; means for concatenating said composite key part with said nonshared key part to generate a resultant value; and means for generating said key as a function of said resultant value.