Cryptographic communication method and cryptographic communication device
First Claim
1. A cryptographic communication method for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number 101 of the sending station, and a secret key d2 of the receiving station, comprising the steps of;
- obtaining the public information P2 in the sending station;
generating a first random number r in the sending station;
generating a second random number R according to a prescribed procedure by utilizing both the public information P2 and the first random number r in the sending station;
generating a third random number X according to a prescribed procedure by utilizing the second random number R in the sending station;
generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r in the sending station;
producing a ciphertext C from the message M by utilizing the cryptographic key K in the sending station;
generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C and the third random number X in the sending station;
generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R, and the hashing result E in the sending station;
sending the third random number X, the identification number ID1, the ciphertext C, and the key-distribution-information Y to the receiving station through the communication line;
generating a second hashing result EO by implementing the one-way hashing to hash both the ciphertext C and the third random number X in the receiving station;
restoring the cryptographic key K according to a prescribed procedure by utilizing both the secret key d2 and the third random number X in the receiving station; and
obtaining the message M by decrypting the ciphertext C by utilizing the cryptographic key K in the receiving station.
1 Assignment
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Accused Products
Abstract
A cryptographic communication method comprises a step for carrying out cryptographic communication between a sending station and one or more receiving stations by using (1) a ciphertext formed by encrypting a unit of sending information under the intervention of at least a cryptographic key and (2) key-distribution-information produced by using at least the ciphertext, receiving station'"'"'s public information, and randomized information generated in the sending station.
82 Citations
8 Claims
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1. A cryptographic communication method for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number 101 of the sending station, and a secret key d2 of the receiving station, comprising the steps of;
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obtaining the public information P2 in the sending station; generating a first random number r in the sending station; generating a second random number R according to a prescribed procedure by utilizing both the public information P2 and the first random number r in the sending station; generating a third random number X according to a prescribed procedure by utilizing the second random number R in the sending station; generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r in the sending station; producing a ciphertext C from the message M by utilizing the cryptographic key K in the sending station; generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C and the third random number X in the sending station; generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R, and the hashing result E in the sending station; sending the third random number X, the identification number ID1, the ciphertext C, and the key-distribution-information Y to the receiving station through the communication line; generating a second hashing result EO by implementing the one-way hashing to hash both the ciphertext C and the third random number X in the receiving station; restoring the cryptographic key K according to a prescribed procedure by utilizing both the secret key d2 and the third random number X in the receiving station; and obtaining the message M by decrypting the ciphertext C by utilizing the cryptographic key K in the receiving station.
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2. A cryptographic communication method for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising the steps of:
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obtaining the public information P2 in the sending station; generating a first random number r in the sending station; generating a second random number R according to a prescribed procedure by utilizing both the public information P2 and the first random number r in the sending station; generating a third random number X according to a prescribed procedure by utilizing the second random number R in the sending station; generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r in the sending station; producing a ciphertext C from the message M by utilizing the cryptographic key K in the sending station; generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C and the third random number X in the sending station; generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R, and the hashing result E in the sending station; sending the hashing result E, the identification number ID1, the ciphertext C, and the key-distribution-information Y to the receiving station through the communication line; generating a fourth random number XO according to a prescribed procedure by utilizing the hashing result E, the key-distribution-information Y, and the identification number ID1 in the receiving station; generating a second hashing result EO by implementing the one-way hashing to hash both the ciphertext C and fourth random number XO in the receiving station; restoring the cryptographic key K according to a prescribed procedure by utilizing both the secret key d2 and the fourth random number XO in the receiving station; and obtaining the message M by decrypting the ciphertext C by utilizing the cryptographic key K in the receiving station.
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3. A cryptographic communication method for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising the steps of:
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obtaining the public information P2 in the sending station; generating a first random number r in the sending station; generating a second random number R according to a prescribed procedure by utilizing both the public information P2 and the first random number r in the sending station; generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r in the sending station; producing a ciphertext C from the message M by utilizing the cryptographic key K in the sending station; generating a first hashing result E by implementing a one-way hashing to hash both the cryptographic key K and the ciphertext C in the sending station; generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R, and the hashing result E in the sending station; sending the hashing result E, the identification number ID1, the ciphertext C, and the key-distribution-information Y to the receiving station through the communication line; generating a fourth random number XO according to a prescribed procedure by utilizing the hashing result E, the identification number ID1, and the key-distribution-information Y in the receiving station; restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 and the fourth random number XO in the receiving station; generating a second hashing result EO by implementing the one-way hashing to hash both the ciphertext C and the cryptographic key K in the receiving station; and obtaining the message M by decrypting the ciphertext C by utilizing the cryptographic key K in the receiving station.
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4. A cryptographic communication method for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising the steps of;
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obtaining the public information P2 in the sending station; generating a first random number r in the sending station; generating a second random number R according to a prescribed procedure by utilizing both the public information P2 and the first random number r in the sending station; generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r in the sending station; producing a ciphertext C from the message M by utilizing the cryptographic key K in the sending station; generating a first hashing result E by implementing a one-way hashing to hash the ciphertext C in the sending station; generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R, and the hashing result E in the sending station; sending the identification number ID1, the ciphertext C and the key-distribution-information Y to the receiving station through the communication line; generating a second hashing result EO by implementing the one-way hashing to hash the ciphertext C in the receiving station; generating a fourth random number XO according to a prescribed procedure by utilizing the second hashing result EO, the identification number ID1, and the key-distribution-information Y in the receiving station; restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 and the fourth random number XO in the receiving station; and obtaining the message M by decrypting the ciphertext C by utilizing the cryptographic key K in the receiving station.
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5. A cryptographic communication device for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising:
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obtaining means in the sending station for obtaining the public information P2; first generating means in the sending station for generating a first random number r; second generating means in the sending station for generating a second random number R according to a prescribed procedure by utilizing both the public information P2 obtained by the obtaining means and the first random number r generated by the first generating means; third generating means in the sending station for generating a third random number X according to a prescribed procedure by utilizing the second random number R generated by the second generating means; fourth generating means in the sending station for generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r generated by the first generating means; producing means in the sending station for producing a ciphertext C from the message M by utilizing the cryptographic key K generated by the fourth generating means; fifth generating means in the sending station for generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C produced by the producing means and the third random number X generated by the third generating means; sixth generating means in the sending station for generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R generated by the second generating means, and the hashing result E generated by the fifth generating means; sending means for sending the third random number X generated by the third generating means, the identification number ID1, the ciphertext C produced by the producing means, and the key-distribution-information Y generated by the sixth generating means to the receiving station through the communication line; seventh generating means in the receiving station for generating a second hashing result EO by implementing the one-way hashing to hash the ciphertext C and the third random number X sent by the sending means; restoring means in the receiving station for restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 and the third random number X sent by the sending means; and obtaining means in the receiving station for obtaining the message M by decrypting the ciphertext C sent by the sending means by utilizing the cryptographic key K restored by the restoring means.
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6. A cryptographic communication device for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising:
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obtaining means in the sending station for obtaining the public information P2; first generating means in the sending station for generating a first random number r; second generating means in the sending station for generating a second random number R according to a prescribed procedure by utilizing both the public information P2 obtained by the obtaining means and the first random number r generated by the first generating means; third generating means in the sending station for generating a third random number X according to a prescribed procedure by utilizing the second random number R generated by the second generating means; fourth generating means in the sending station for generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r generated by the first generating means; producing means in the sending station for producing a ciphertext C from the message M by utilizing the cryptographic key K generated by the fourth generating means; fifth generating means in the sending station for generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C produced by the producing means and the third random number X generated by the third generating means; sixth generating means in the sending station for generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R generated by the second generating means, and the hashing result E generated by the fifth generating means; sending means for sending the first hashing result E generated by the fifth generating means, the identification number ID1, the ciphertext C produced by the producing means, and the key-distribution-information Y generated by the sixth generating means to the receiving station through the communcation line; seventh generating means in the receiving station for generating a fourth random number XO according to a prescribed procedure by utilizing the hashing result E, the key-distribution-information Y, and the identification number ID1 sent by the sending means; eighth generating means in the receiving station for generating a second hashing result EO by implementing the one-way hashing to hash the ciphertext C and the fourth random number XO sent by the sending means; restoring means in the receiving station for restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 and the fourth random number XO sent by the sending means; and obtaining means in the receiving station for obtaining the message M by decrypting the ciphertext C sent by the sending means by utilizing the cryptographic key K restored by the restoring means.
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7. A cryptographic communication device for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising:
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obtaining means in the sending station for obtaining the public information P2; first generating means in the sending station for generating a first random number r; second generating means in the sending station for generating a second random number R according to a prescribed procedure by utilizing both the public information P2 obtained by the obtaining means and the first random number r generated by the first generating means; third generating means in the sanding station for generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r generated by the first generating means; producing means in the sending station for producing a ciphertext C from the message M by utilizing the cryptographic key K generated by the third generating means; fourth generating means in the sending station for generating a first hashing result E by implementing a one-way hashing to hash both the ciphertext C produced by the producing means and the cryptographic key K generated by the third generating means; fifth generating means in the sending station for generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R generated by the second generating means, and the hashing result E generated by the fourth generating means; sending means for sending the first hashing result E generated by the fourth generating means, the identification number ID1, the ciphertext C produced by the producing means, and the key-distribution-information Y generated by the fifth generating means to the receiving station through the communication line; sixth generating means in the receiving station for generating a fourth random number XO according to a prescribed procedure by utilizing the hashing result E, the key-distribution-information Y, and the identification number ID1 sent by the sending means; restoring means in the receiving station for restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 and the fourth random number XO sent by the sending means; and seventh generating means in the receiving station for generating a second hashing result EO by implementing the one-way hashing to hash the ciphertext C sent by the sending means and the cryptographic key K restored in the restoring means; obtaining means in the receiving station for obtaining the message M by decrypting the ciphertext C sent by the sending means by utilizing the cryptographic key K restored by the restoring means.
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8. A cryptographic communication device for carrying out cryptographic communication to transmit a message M from a sending station to a receiving station through a communication line by utilizing public information P2 of the receiving station, secret information S1 of the sending station, an identification number ID1 of the sending station, and a secret key d2 of the receiving station, comprising:
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obtaining means in the sending station for obtaining the public information P2; first generating means in the sending station for generating a first random number r; second generating means in the sending station for generating a second random number R according to a prescribed procedure by utilizing both the public information P2 obtained by the obtaining means and the first random number r generated by the first generating means; third generating means in the sending station for generating a cryptographic key K according to a prescribed procedure by utilizing the first random number r generated by the first generating means; producing means in the sending station for producing a ciphertext C from the message M by utilizing the cryptographic key K generated by the third generating means; fourth generating means in the sending station for generating a first hashing result E by implementing a one-way hashing to hash the ciphertext C produced by the producing means; fifth generating means in the sending station for generating key-distribution-information Y according to a prescribed procedure by utilizing the secret information S1, the second random number R generated by the second generating means, and the hashing result E generated by the fourth generating means; sending means for sending the first hashing result E generated by the fourth generating means, the identification number ID1, the ciphertext C produced by the producing means, and the key-distribution-information Y generated by the fifth generating means to the receiving station through the communication line; sixth generating means in the receiving station for generating a second hashing result EO by implementing the one-way hashing to hash the ciphertext C sent by the sending means; seventh generating means in the receiving station for generating a fourth random number XO according to a prescribed procedure by utilizing the second hashing result EO generated by the sixth generating means, the key-distribution-information Y, and the identification number ID1 sent by the sending means; restoring means in the receiving station for restoring the cryptographic key K according to a prescribed procedure by utilizing the secret key d2 sent by the sending means and the fourth random number XO generated by the seventh generating means; and obtaining means in the receiving station for obtaining the message M by decrypting the ciphertext C sent by the sending means by utilizing the cryptographic key X restored by the restoring means.
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Specification