Nova Patents
US20100180119A1

Key exchanging apparatus

Claim Score by NHIP

Read claim 9, the broadest

Abstract

A key exchanging apparatus transmits the contribution data to the plurality of counterpart apparatuses, generates a signer contribution confirmation signature with respect to a contribution data set including all the contribution data received from the plurality of counterpart apparatuses, generates auxiliary data and auxiliary data validity certification sentence from the contribution data set and the contribution random number, transmits the auxiliary data, the auxiliary data validity certification sentence and the contribution confirmation signature to the plurality of counterpart apparatuses, verifies validity of auxiliary data by using the counterpart identifier set, the counterpart public key set, the contribution confirmation signature set including the data received from the plurality of counterpart apparatuses, the auxiliary data set and the auxiliary data validity certification sentence set, and generates a public key from the contribution data set and the auxiliary data received from the plurality of counterpart apparatuses.

US20100180119A1, drawing sheet 1
Sheet 1 of 5

Term

4.4 yearsto projected expiry

Projected expiry 27 February 2031, counted from filing; an application has no term until it is granted.

  1. Priority
  2. Filed
  3. Published
  4. Today
  5. Projected expiry

7 claims: 4 independent, 3 dependent

  1. 6
    A key exchanging apparatus which receives a public key, a secret key, an identifier, a counterpart public key set, a counterpart identifier set, a session number, and a random number inputted thereto, performs communication with a plurality of counterpart apparatuses identified by identifiers belonging to the counterpart identifier set, and generates and outputs a public key, the apparatus comprising:a contribution random number generating unit that generates a contribution random number by using the random number;a contribution data generating unit that generates contribution data from the contribution random number generated by the contribution random number generating unit;a communication unit that transmits the contribution data to the plurality of counterpart apparatuses;a signing unit that generates a signer contribution confirmation signature with respect to a contribution data set including every contribution data received by the communication unit from the plurality of counterpart apparatuses by using the secret key and the public key;a verifiable auxiliary data generating unit that generates auxiliary data and an auxiliary data validity certification sentence from the contribution data set and the contribution random number, the auxiliary data, the auxiliary data validity certification sentence and the contribution confirmation signature being transmitted to the plurality of counterpart apparatuses by the communication unit;a validity verifying unit that verifies validity of the auxiliary data by using the counterpart identifier set and the counterpart public key set, the contribution confirmation signature set, the auxiliary data set and the auxiliary data validity certification sentence including data received by the communication unit from the plurality of counterpart apparatus;and a key generating unit that generates the public key from the contribution data set and the auxiliary data received by the communication unit from the plurality of counterpart apparatus.
  2. 9
    Broadest claimClaim Score 35, narrow(NHIP)A key exchanging method in which a public key, a secret key, an identifier, a counterpart public key set, a counterpart identifier set, a session number and a random number are assigned, communication with a plurality of counterpart apparatuses identified by identifiers belonging to the counterpart identifier set is performed, and a public key is generated and outputted, the method comprising:generating a contribution random number by using the random number;generating contribution data from the contribution random number;transmitting the contribution data to the plurality of counterpart apparatuses;generating a signer contribution confirmation signature with respect to a contribution data set including all the contribution data received from the plurality of counterpart apparatuses by using the secret key and the public key;generating auxiliary data and an auxiliary data validity certification sentence from the contribution data set and the contribution random number, transmitting the auxiliary data, the auxiliary data validity certification sentence and the contribution confirmation signature to the plurality of counterpart apparatuses;verifying validity of the auxiliary data by using the counterpart identifier set and the counterpart public key set, the contribution confirmation signature set the auxiliary data set and the auxiliary data validity certification sentence including data received from the plurality of counterpart apparatus;and generating the public key by the contribution data set and the auxiliary data received from the plurality of counterpart apparatus.
  3. 10
    A record medium storing a program for a key exchanging apparatus which receives a public key, a secret key, an identifier, a counterpart public key set, a counterpart identifier set, a session number, and a random number inputted thereto, performs communication with a plurality of counterpart apparatuses identified by identifiers belonging to the counterpart identifier set, and generates and outputs a public key, said program comprising:the order of generating a contribution random number by using the random number;the order of generating contribution data from the contribution random number;the order of transmitting the contribution data to the plurality of counterpart apparatuses;the order of generating a signer contribution confirmation signature with respect to a contribution data set including every contribution data received by from the plurality of counterpart apparatuses by using the secret key and the public key;the order of generating auxiliary data and an auxiliary data validity certification sentence by the contribution data set and the contribution random number, the order of transmitting the auxiliary data, the auxiliary data validity certification sentence, and the contribution confirmation signature to the plurality of counterpart apparatuses;the order of verifying validity of the auxiliary data by using the counterpart identifier set and the counterpart public key set, and the contribution confirmation signature set the auxiliary data set and the auxiliary data validity certification sentence including data received from the plurality of counterpart apparatus;and the order of generating the public key from the contribution data set and the auxiliary data received from the plurality of counterpart apparatuses.