Parameter generation apparatus, encryption system, decryption system, encryption apparatus, decryption apparatus, encryption method, decryption method, and program thereof
First Claim
1. A parameter generation apparatus for generating an output parameter that is a set of parameters causing no decryption error for an NTRU cryptosystem, the parameter generation apparatus comprising an error-free output parameter generation unit operable to generate the output parameter that does not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error.
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Accused Products
Abstract
A parameter generation apparatus for generating parameters causing no decryption error for an NTRU cryptosystem so that an encrypted communication can be carried out between an encryption apparatus and a decryption apparatus in a secure and reliable manner, is comprised of: a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and an output parameter generation unit operable to generate an output parameter that does not cause any decryption errors, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters.
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Citations
37 Claims
- 1. A parameter generation apparatus for generating an output parameter that is a set of parameters causing no decryption error for an NTRU cryptosystem, the parameter generation apparatus comprising an error-free output parameter generation unit operable to generate the output parameter that does not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error.
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18. An encryption system for generating an encrypted text by encrypting a plain text in compliance with an NTRU cryptosystem, the encryption system comprising:
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a parameter generation apparatus that includes an error-free output parameter generation unit operable to generate an output parameter that does not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
a public key generation unit operable to generate a public key based on the output parameter generated by the parameter generation apparatus; and
an encryption unit operable to encrypt the plain text based on the public key.
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19. A decryption system for generating a decrypted text by decrypting an encrypted text in compliance with an NTRU cryptosystem, the decryption system comprising:
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a parameter generation apparatus that includes an error-free output parameter generation unit operable to generate an output parameter that does not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
a private key generation unit operable to generate a private key based on the output parameter generated by the parameter generation apparatus; and
a decryption unit operable to decrypt the encrypted text based on the private key.
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20. An encryption system using an NTRU cryptosystem, comprising:
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a parameter generation apparatus for generating and outputting an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting an encryption key and a decryption key for the NTRU cryptosystem;
an encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with the NTRU cryptosystem; and
a decryption apparatus for generating a decrypted text by decrypting the encrypted text, wherein the parameter generation apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the encryption key and the decryption key, using the output parameter inputted from the parameter generation apparatus, and output the generated encryption key and decryption key, the encryption apparatus includes an encryption unit operable to generate the encrypted text by encrypting the plain text, using the output parameter inputted from the parameter generation apparatus and the encryption key inputted from the key generation apparatus, and the decryption apparatus includes a decryption unit operable to generate the decrypted text by decrypting the encrypted text, using the output parameter inputted from the parameter generation apparatus and the decryption key inputted from the key generation apparatus.
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21. An encryption system using an NTRU cryptosystem, comprising:
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a parameter generation apparatus for generating and outputting an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting an encryption key for the NTRU cryptosystem; and
an encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with the NTRU cryptosystem, wherein the parameter generation apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the encryption key, using the output parameter inputted from the parameter generation apparatus, and output the generated encryption key, and the encryption apparatus includes an encryption unit operable to generate the encrypted text by encrypting the plain text, using the output parameter inputted from the parameter generation apparatus and the encryption key inputted from the key generation apparatus.
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22. An encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with an NTRU cryptosystem, the encryption apparatus comprising:
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a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
an output parameter generation unit operable to generate an output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a parameter transmission unit operable to transmit the output parameter to a decryption apparatus;
an encryption key receiving unit operable to receive, from the decryption apparatus, an encryption key for the NTRU cryptosystem that is generated based on the output parameter; and
an encrypted text generation unit operable to generate the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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23. An encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with an NTRU cryptosystem, the encryption apparatus comprising:
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a parameter receiving unit operable to receive an output parameter that does not cause any decryption errors and that is generated based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
a public key generation unit operable to generate a public key based on the output parameter received by the parameter receiving unit; and
an encryption unit operable to encrypt the plain text based on the public key.
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24. An encryption method for generating an encrypted text by encrypting a plain text in compliance with NTRU cryptosystem, the encryption method comprising the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating an encryption key for the NTRU cryptosystem based on the output parameter; and
generating the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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25. A program for generating an encrypted text by encrypting a plain text in compliance with NTRU cryptosystem, the program causing a computer to execute the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating an encryption key for the NTRU cryptosystem based on the output parameter; and
generating the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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26. A decryption system using an NTRU cryptosystem, comprising:
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a parameter generation apparatus for generating and outputting an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting a decryption key for the NTRU cryptosystem; and
a decryption apparatus for generating a decrypted text by decrypting an encrypted text in compliance with the NTRU cryptosystem, wherein the parameter generation apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the decryption key, using the output parameter inputted from the parameter generation apparatus, and output the generated decryption key, and the decryption apparatus includes a decryption unit operable to generate the decrypted text by decrypting the encrypted text, using the output parameter inputted from the parameter generation apparatus and the decryption key inputted from the key generation apparatus.
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27. A decryption apparatus for generating a decrypted text by decrypting an encrypted text received from an encryption apparatus in compliance with an NTRU cryptosystem, the decryption apparatus comprising:
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a parameter receiving unit operable to receive, from the encryption apparatus, an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a generated key generation unit operable to generate an encryption key and a decryption key for the NTRU cryptosystem, using the inputted output parameter, and output the generated encryption key and decryption key;
an encryption key transmission unit operable to transmit the encrypted key to the encryption apparatus; and
a decrypted text generation unit operable to generate the decrypted text by decrypting the encrypted text based on the output parameter and the decryption key.
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28. A decryption method for generating a decrypted text by decrypting an encrypted text in compliance with NTRU cryptosystem, the decryption method comprising the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating a decryption key for the NTRU cryptosystem based on the output parameter; and
generating the decrypted text by decrypting the encrypted text, based on the output parameter and the decryption key.
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29. A program for generating a decrypted text by decrypting an encrypted text in compliance with NTRU cryptosystem, the program causing a computer to execute the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating a decryption key for the NTRU cryptosystem based on the output parameter; and
generating the decrypted text by decrypting the encrypted text, based on the output parameter and the decryption key.
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30. An encryption system using an NTRU cryptosystem, comprising:
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a parameter conversion apparatus for converting, into an output parameter, an input parameter that is a set of parameters for the NTRU cryptosystem that are inputted from outside, said output parameter being a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting an encryption key and a decryption key for the NTRU cryptosystem;
an encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with the NTRU cryptosystem; and
a decryption apparatus for generating a decrypted text by decrypting the encrypted text, wherein the parameter conversion apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on the input parameter and error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the encryption key and the decryption key, using the output parameter inputted from the parameter conversion apparatus, and output the generated encryption key and decryption key, the encryption apparatus includes an encryption unit operable to generate the encrypted text by encrypting the plain text, using the output parameter inputted from the parameter conversion apparatus and the encryption key inputted from the key generation apparatus, and the decryption apparatus includes a decryption unit operable to generate the decrypted text by decrypting the encrypted text, using the output parameter inputted from the parameter conversion apparatus and the decryption key inputted from the key generation apparatus.
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31. An encryption system using an NTRU cryptosystem, comprising:
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a parameter generation apparatus for generating an output parameter from an input parameter that is a set of parameters for the NTRU cryptosystem that are inputted from outside, and outputting the generated output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting an encryption key for the NTRU cryptosystem; and
an encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with the NTRU cryptosystem, wherein the parameter generation apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on the input parameter and error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the encryption key, using the output parameter inputted from the parameter generation apparatus, and output the generated encryption key, and the encryption apparatus includes an encryption unit operable to generate the encrypted text by encrypting the plain text, using the output parameter inputted from the parameter generation apparatus and the encryption key inputted from the key generation apparatus.
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32. An encryption apparatus for generating an encrypted text by encrypting a plain text in compliance with an NTRU cryptosystem, the encryption apparatus comprising:
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a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on an input parameter that is a set of parameters for the NTRU cryptosystem and error condition information indicating a condition for causing no decryption error, said input parameter and error condition information being provided in advance;
an output parameter generation unit operable to generate an output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a parameter transmission unit operable to transmit the output parameter to a decryption apparatus;
an encryption key receiving unit operable to receive, from the decryption apparatus, an encryption key for the NTRU cryptosystem that is generated based on the output parameter; and
an encrypted text generation unit operable to generate the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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33. An encryption method for generating an encrypted text by encrypting a plain text in compliance with NTRU cryptosystem, the encryption method comprising the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on an input parameter that is a set of parameters for the NTRU cryptosystem and error condition information indicating a condition for causing no decryption error, said input parameter and error condition information being provided in advance;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating an encryption key for the NTRU cryptosystem based on the output parameter; and
generating the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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34. A program for generating an encrypted text by encrypting a plain text in compliance with NTRU cryptosystem, the program causing a computer to execute the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on an input parameter that is a set of parameters for the NTRU cryptosystem and error condition information indicating a condition for causing no decryption error, said input parameter and error condition information being provided in advance;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating an encryption key for the NTRU cryptosystem based on the output parameter; and
generating the encrypted text by encrypting the plain text, based on the output parameter and the encryption key.
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35. A decryption system using an NTRU cryptosystem, comprising:
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a parameter generation apparatus for generating an output parameter from an input parameter that is a set of parameters for the NTRU cryptosystem that are inputted from outside, and outputting the generated output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem;
a key generation apparatus for generating and outputting a decryption key for the NTRU cryptosystem; and
a decryption apparatus for generating a decrypted text by decrypting an encrypted text in compliance with the NTRU cryptosystem, wherein the parameter generation apparatus includes;
a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on the input parameter and error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and
an output parameter generation unit operable to generate the output parameter, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and output the generated output parameter, the key generation apparatus includes a generated key output unit operable to generate the decryption key, using the output parameter inputted from the parameter generation apparatus, and output the generated decryption key, and the decryption apparatus includes a decryption unit operable to generate the decrypted text by decrypting the encrypted text, using the output parameter inputted from the parameter generation apparatus and the decryption key inputted from the key generation apparatus.
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36. A decryption method for generating a decrypted text by decrypting an encrypted text in compliance with NTRU cryptosystem, the decryption method comprising the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on an input parameter that is a set of parameters for the NTRU cryptosystem and error condition information indicating a condition for causing no decryption error, said input parameter and error condition information being provided in advance;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating a decryption key for the NTRU cryptosystem based on the output parameter; and
generating the decrypted text by decrypting the encrypted text, based on the output parameter and the decryption key.
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37. A program for generating a decrypted text by decrypting an encrypted text in compliance with NTRU cryptosystem, the program causing a computer to execute the following steps of:
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generating a set of provisional parameters that do not cause any decryption errors, based on an input parameter that is a set of parameters for the NTRU cryptosystem and error condition information indicating a condition for causing no decryption error, said input parameter and error condition information being provided in advance;
generating an output parameter that is a set of parameters causing no decryption error for the NTRU cryptosystem, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters, and outputting said generated output parameter;
generating a decryption key for the NTRU cryptosystem based on the output parameter; and
generating the decrypted text by decrypting the encrypted text, based on the output parameter and the decryption key.
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Specification