GENERATION OF A DIGITAL SIGNATURE
First Claim
1. A method for generating a digital signature of a data item, said method comprising:
- a computer iteratively processing a unique condition digest of a plurality of condition digests in each iteration of a loop for a sufficient number of iterations to process all condition digests of the plurality of condition digests, said processing in each iteration comprising concatenating a reference digest with the unique condition digest of the iteration to generate a concatenand and hashing the concatenand to generate a hashed concatenand that serves as the reference digest for the next iteration if the next iteration is performed, each unique condition digest being a different condition digest in each iteration of the loop, the regenerated reference digest of the last iteration of the loop being a last digest; and
said computer encrypting the last digest to generate a digital signature block that represents the data item and a plurality of conditions specified for the digital signature, said digital signature block comprising the digital signature and enabling cryptographic verification of both the data item and the plurality of conditions, said encrypting comprising signing the last digest with the digital signature.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and system for generating a digital signature of a data item. A unique condition digest of at least two condition digests is iteratively processed in each iteration of a loop for a sufficient number of iterations to process all of the condition digests. Each iteration includes concatenating a reference digest with the unique condition digest of the iteration to generate a concatenand and hashing the concatenand to generate a hashed concatenand serving as the reference digest for the next iteration. Each unique condition digest is a different condition digest in each iteration. The regenerated reference digest of the last iteration is a last digest which is encrypted to generate a digital signature block that represents the data item and at least two conditions specified for the digital signature. The digital signature block includes the digital signature. The encrypting includes signing the last digest with the digital signature.
-
Citations
20 Claims
-
1. A method for generating a digital signature of a data item, said method comprising:
-
a computer iteratively processing a unique condition digest of a plurality of condition digests in each iteration of a loop for a sufficient number of iterations to process all condition digests of the plurality of condition digests, said processing in each iteration comprising concatenating a reference digest with the unique condition digest of the iteration to generate a concatenand and hashing the concatenand to generate a hashed concatenand that serves as the reference digest for the next iteration if the next iteration is performed, each unique condition digest being a different condition digest in each iteration of the loop, the regenerated reference digest of the last iteration of the loop being a last digest; and said computer encrypting the last digest to generate a digital signature block that represents the data item and a plurality of conditions specified for the digital signature, said digital signature block comprising the digital signature and enabling cryptographic verification of both the data item and the plurality of conditions, said encrypting comprising signing the last digest with the digital signature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A computer program product, comprising a machine-readable recording medium having program code recorded thereon, said program code upon being executed by a computer performs a method for generating a digital signature of a data item, said method comprising:
-
said computer iteratively processing a unique condition digest of a plurality of condition digests in each iteration of a loop for a sufficient number of iterations to process all condition digests of the plurality of condition digests, said processing in each iteration comprising concatenating a reference digest with the unique condition digest of the iteration to generate a concatenand and hashing the concatenand to generate a hashed concatenand that serves as the reference digest for the next iteration if the next iteration is performed, each unique condition digest being a different condition digest in each iteration of the loop, the regenerated reference digest of the last iteration of the loop being a last digest; and said computer encrypting the last digest to generate a digital signature block that represents the data item and a plurality of conditions specified for the digital signature, said digital signature block comprising the digital signature and enabling cryptographic verification of both the data item and the plurality of conditions, said encrypting comprising signing the last digest with the digital signature. - View Dependent Claims (10, 11, 12, 13, 14)
-
-
15. A data processing apparatus comprising a computer and a machine-readable recording medium coupled to the computer, said recording medium storing program code that when executed by the computer performs a method for generating a digital signature of a data item, said method comprising:
-
said computer iteratively processing a unique condition digest of a plurality of condition digests in each iteration of a loop for a sufficient number of iterations to process all condition digests of the plurality of condition digests, said processing in each iteration comprising concatenating a reference digest with the unique condition digest of the iteration to generate a concatenand and hashing the concatenand to generate a hashed concatenand that serves as the reference digest for the next iteration if the next iteration is performed, each unique condition digest being a different condition digest in each iteration of the loop, the regenerated reference digest of the last iteration of the loop being a last digest; and said computer encrypting the last digest to generate a digital signature block that represents the data item and a plurality of conditions specified for the digital signature, said digital signature block comprising the digital signature and enabling cryptographic verification of both the data item and the plurality of conditions, said encrypting comprising signing the last digest with the digital signature. - View Dependent Claims (16, 17, 18, 19, 20)
-
Specification