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AssigneeNEC Corporation
InventorJun Furukawa
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A shuffle with proof having a method for proof generating with a small computational resources proportionate to the number of input encrypted messages and a corresponding method for verification. Shuffle is represented by a generalized transformation. Combining a proof that the transformation information is retained and a proof of a condition under which the transformation is met constitute the proof for shuffle. The two proofs are short proportional to the number of input encrypted messages. Transformation information retention is proved in such a manner that, since the response is generated from challenge value in dependency upon transformation, the condition under which the transformation is met is reflected in the response-challenge value relation, the response-challenge value relation not dependent on the challenge value exists. The above relation retention true proves the condition under which the transformation is met. If the condition under which the transformation corresponding to the shuffle is selected as the condition for proof, the two proofs may constitute the proof for shuffle.
A method for shuffle with proof in which an input message sequence, which is comprised of encrypted messages and one or more public-keys, and shuffle information are input, and in which an encrypted output message sequence obtained by processing permutation of said encrypted messages and re-encryption by said public key or keys, and a shuffle proof text as a proof text for said processing, are output, the method comprising:
A shuffle verifying method in which an input message sequence, an output encrypted message sequence and a shuffle proof text are input, and a result of verification indicating acceptance or non-acceptance is output, the method comprising:
An input message sequence generating method comprising:
A method for generating a public key sequence with proof comprising:
An apparatus for shuffle with proof in which input message sequence, which is including a plurality of input encrypted messages and one or more publ ic keys, and the shuffle information including the manner of permuting the input encrypted messages, variables used for re-encryption and random numbers is input, and an output encrypted message sequence obtained on permutation of said encrypted message and re-encryption by said public key and a shuffle proof text are output, said apparatus comprising:
A shuffle verification apparatus which (a) receives inputs, and in which (b) the result of verification, i.e., acceptance or non-acceptance is output;
An apparatus for generating a public key sequence with proof wherein
A machine readable program so formulated that a computer, as a shuffle apparatus, in which an input message sequence, which is including a plurality of input encrypted messages and one or more public keys, and the shuffle information, including the manner of permuting the input encrypted message, variables used for re-encryption and random numbers, are input, and in which an encrypted output message sequence obtained on permutation of said encrypted messages and re-encryption by said public key or keys, and a shuffle proof text, are output, is caused to perform the processing comprising:
A machine readable program so formulated that a computer, as a shuffle verifying apparatus, in which an input message sequence, an output encrypted message sequence output by a device for shuffle verifying with proof, the transformation information retention commitment, output from a device for shuffle with proof, pertinent to retention of the transformation information from said input message sequence to said output encrypted message sequence, a transformation condition commitment, pertinent to the condition to be met by said transformation, and a shuffle proof text including a response, are input, and a result of verification indicating acceptance or non-acceptance is output, to perform the processing comprising:
A machine readable program for allowing a computer to perform the processings of:
Dependencies are inferred from the claim text.