Key exchange device, key exchange processing system, key exchange method, and program

A key exchange processing system comprising:

• a first key exchange apparatus including a first storage and a first CPU executing processes according to a program, for performing a key exchange process with a second key exchange apparatus through a network;
• and
• said second key exchange apparatus including a second storage and a second CPU executing processes according to a program, for performing said key exchange process with said first key exchange apparatus through said network, wherein
• when said first CPU is supplied with a random number, a private key, an own public key which is the public key of its own apparatus, a companion public key which is the public key of said second key exchange apparatus, an initial session number, and a start command, said first CPU generates a starter session number which is different from said initial sessions number by assigning a value generated from said random number to a variable of said own public key, generates a first hash value by using information of said starter session number, said random number, and said private key, generates a first session number including said initial session number, said starter session number, said own public key, and said companion public key, and sends a first starter message including said first session number and said first hash value to said second key exchange apparatus;
• when said second CPU receives said first starter message from said first key exchange apparatus, said second CPU determines whether a second hash value generated using information of said first session number and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said second CPU generates a responder session number which is different from any one of said initial session number and said starter session number, generates a third hash value using information of a second session number that is generated by adding said responder session number to said first session number, stores an arithmetic result included in said third hash value in said second storage, generates a responder message including said second session number and said third hash value, and sends the responder message to said first key exchange apparatus;
• when said first CPU receives said responder message from said second key exchange apparatus, said first CPU determines whether a fourth hash value generated using information of said second session number and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said first CPU generates a fifth hash value using information of said second session number, stores said fifth hash value as a key in said first storage, and sends a second starter message including said second session number and said fifth hash value to said second key exchange apparatus;
• and
• when said second CPU receives said second starter message from said first key exchange apparatus, said second CPU determines whether a sixth hash value generated using information of said second session number and said fifth hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said second CPU generates a sixth hash value using said arithmetic result and information of said second session number, and stores said sixth hash value as a key in said second storage.

A key exchange processing system comprising:

• a first key exchange apparatus including a first storage and a first CPU executing processes according to a program, for performing a key exchange process with a second key exchange apparatus through a network;
• and
• said second key exchange apparatus including a second storage and a second CPU executing processes according to a program, for performing said key exchange process with said first key exchange apparatus through said network, wherein
• when said first CPU is supplied with a random number, a first private key, an own apparatus number which is the identifier of its own apparatus, a companion apparatus number which is the identifier key of said second key exchange apparatus, an initial session number, and a start command, said first CPU generates a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key, generates a first cryptotext using information of said starter session number and said random number, generates a first hash value by using information of said starter session number, said random number, and said first private key, generates a first session number including said initial session number, said starter session number, said own apparatus number, and said companion apparatus number, and sends a starter message including said first session number, said first cryptotext, and said first hash value to said second key exchange apparatus;
• when said second CPU receives said starter message from said first key exchange apparatus, said second CPU decrypts said first cryptotext using information of said first session number and a second private key, generates a second hash value including decrypted result, determines whether the second hash value and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said second CPU generates a responder session number which is different from any one of said initial session number and said starter session number, generates a second session number by adding said responder session number to said first session number, generates a second cryptotext using information of said second session number and said random number, generates a third hash value including information of said second session number and said second private key, stores said third hash value as a key in said second storage, and sends a responder message including said second session number, said second cryptotext, and said third hash value to said first key exchange apparatus;
• and
• when said first CPU receives said responder message from said second key exchange apparatus, said first CPU decrypts said second cryptotext using information of said second session number and said first private key, generates a fourth hash value including decrypted result, determines whether the fourth hash value and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said first CPU generates a fifth hash value including information of said second session number and said first private key, and stores said fifth hash value as a key in said first storage.

A key exchange processing system comprising:

• a first key exchange apparatus including a first storage and a first CPU executing processes according to a program, for performing a key exchange process with a second key exchange apparatus through a network;
• and
• said second key exchange apparatus including a second storage and a second CPU executing processes according to a program, for performing said key exchange process with said first key exchange apparatus through said network, wherein
• when said first CPU is supplied with a random number, a first private key, an own apparatus number which is the identifier of its own apparatus, a companion apparatus number which is the identifier key of said second key exchange apparatus, an initial session number, and a start command, said first CPU generates a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key, generates a first cryptotext using information of said starter session number and said random number, generates a first hash value by using information of said starter session number, said random number, and said first private key, generates a first session number including said initial session number, said starter session number, said own apparatus number, and said companion apparatus number, and sends a first starter message including said first session number, said first cryptotext, and said first hash value to said second key exchange apparatus;
• when said second CPU receives said first starter message from said first key exchange apparatus, said second CPU decrypts said first crypto-text using information of said first session number and a second private key, generates a second hash value including decrypted result, determines whether the second hash value and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said second CPU generates a responder session number which is different from any one of said initial session number and said starter session number, generates a second session number by adding said responder session number to said first session number, generates a second cryptotext using information of said second session number and said random number, generates a third hash value including information of said second session number and said second private key, stores an arithmetic result included in said third hash value in said second storage, and sends a responder message including said second session number, said second cryptotext, and said third hash value to said first key exchange apparatus;
• when said first CPU receives said responder message from said second key exchange apparatus, said first CPU decrypts said second cryptotext using information of said second session number and said first private key, generates a fourth hash value including decrypted result, determines whether the fourth hash value and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said first CPU generates a fifth hash value including information of said second session number and said first private key, stores said fifth hash value as a key in said first storage, and sends a second starter message including said second session number and said fifth hash value to said second key exchange apparatus;
• and
• when said second CPU receives said second starter message from said first key exchange apparatus, said second CPU determines whether a sixth hash value generated using information of said second session number and said fifth hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, said second CPU generates a sixth hash value using said arithmetic result and information of said second session number, and stores said sixth hash value as a key in said second storage.

A key exchange method to be carried out by a first CPU of a first key exchange apparatus and a second CPU of a second key exchange apparatus for performing a key exchange process with each other through a network, said first key exchange apparatus including a first storage and said first CPU, and said second key exchange apparatus including a second storage and said second CPU, said key exchange method comprising:

• when a random number, a private key, an own public key which is the public key of its own apparatus, a companion public key which is the public key of said second key exchange apparatus, an initial session number, and a start command are supplied to said first key exchange apparatus, generating, by said first CPU, a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key, and generating a first hash value by using information of said starter session number, said random number, and said private key;
• generating, by said first CPU, a first session number including said initial session number, said starter session number, said own public key, and said companion public key, and sending a starter message including said first session number and said first hash value to said second key exchange apparatus;
• when said starter message is received from said first key exchange apparatus, determining, by said second CPU, whether a second hash value generated using information of said first session number and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, and generating a responder session number which is different from any one of said initial session number and said starter session number;
• generating, by said second CPU, a third hash value using information of a second session number that is generated by adding said responder session number to said first session number, storing said third hash value as a key in said second storage, generating a responder message including said second session number and said third hash value, and sending the responder message to said first key exchange apparatus;
• and
• when said responder message is received from said second key exchange apparatus, determining, by said first CPU, whether a fourth hash value generated using information of said second session number and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a fifth hash value using information of said second session number, and storing said fifth hash value as a key in said first storage.

A key exchange method to be carried out by a first CPU of a first key exchange apparatus and a second CPU of a second key exchange apparatus for performing a key exchange process with each other through a network, said first key exchange apparatus including a first storage and said first CPU, and said second key exchange apparatus including a second storage and said second CPU, said key exchange method comprising:

• when a random number, a private key, an own public key which is the public key of its own apparatus, a companion public key which is the public key of said second key exchange apparatus, an initial session number, and a start command are supplied to said first key exchange apparatus, generating, by said first CPU, a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key, and generating a first hash value by using information of said starter session number, said random number, and said private key;
• generating, by said first CPU, a first session number including said initial session number, said starter session number, said own public key, and said companion public key, and sending a first starter message including said first session number and said first hash value to said second key exchange apparatus;
• when said first starter message is received from said first key exchange apparatus, determining, by said second CPU, whether a second hash value generated using information of said first session number and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a responder session number which is different from any one of said initial session number and said starter session number;
• generating, by said second CPU, a third hash value using information of a second session number that is generated by adding said responder session number to said first session number, storing an arithmetic result included in said third hash value in said second storage, generating a responder message including said second session number and said third hash value, and sending the responder message to said first key exchange apparatus;
• when said responder message is received from said second key exchange apparatus, determining, by said first CPU, whether a fourth hash value generated using information of said second session number and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a fifth hash value using information of said second session number, storing said fifth hash value as a key in said first storage, and sending a second starter message including said second session number and said fifth hash value to said second key exchange apparatus;
• and
• when said second starter message is received from said first key exchange apparatus, determining, by said second CPU, whether a sixth hash value generated using information of said second session number and said fifth hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a sixth hash value using said arithmetic result and information of said second session number, and storing said sixth hash value as a key in said second storage.

A key exchange method to be carried out by a first CPU of a first key exchange apparatus and a second CPU of a second key exchange apparatus for performing a key exchange process with each other through a network, said first key exchange apparatus including a first storage and said first CPU, and said second key exchange apparatus including a second storage and said second CPU, said key exchange method comprising:

• when a random number, a first private key, an own apparatus number which is the identifier of said first key exchange apparatus, a companion apparatus number which is the identifier key of said second key exchange apparatus, an initial session number, and a start command are supplied to said first key exchange apparatus, generating, by said first CPU, a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key;
• generating, by said first CPU, a first cryptotext using information of said starter session number and said random number, generating a first hash value by using information of said starter session number, said random number, and said first private key, generating a first session number including said initial session number, said starter session number, said own apparatus number, and said companion apparatus number, and sending a starter message including said first session number, said first cryptotext, and said first hash value to said second key exchange apparatus;
• when said starter message is received from said first key exchange apparatus, decrypting, by said second CPU, said first cryptotext using information of said first session number and a second private key, generating a second hash value including decrypted result, determining whether the second hash value and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a responder session number which is different from any one of said initial session number and said starter session number, generating a second session number by adding said responder session number to said first session number;
• generating, by said second CPU, a second cryptotext using information of said second session number and said random number, generating a third hash value including information of said second session number and said second private key, storing said third hash value as a key in said second storage, and sending a responder message including said second session number, said second cryptotext, and said third hash value to said first key exchange apparatus;
• and
• when said responder message is received from said second key exchange apparatus, decrypting, by said first CPU, said second cryptotext using information of said second session number and said first private key, generating a fourth hash value including decrypted result, determining whether the fourth hash value and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a fifth hash value including information of said second session number and said first private key, and storing said fifth hash value as a key in said first storage.

A key exchange method to be carried out by a first CPU of a first key exchange apparatus and a second CPU of a second key exchange apparatus for performing a key exchange process with each other through a network, said first key exchange apparatus including a first storage and said first CPU, and said second key exchange apparatus including a second storage and said second CPU, said key exchange method comprising:

• when a random number, a first private key, an own apparatus number which is the identifier of said first key exchange apparatus, a companion apparatus number which is the identifier key of said second key exchange apparatus, an initial session number, and a start command are supplied to said first key exchange apparatus, generating, by said first CPU, a starter session number which is different from said initial session number by assigning a value generated from said random number to a variable of said own public key;
• generating, by said first CPU, a first cryptotext using information of said starter session number and said random number, generating a first hash value by using information of said starter session number, said random number, and said first private key, generating a first session number including said initial session number, said starter session number, said own apparatus number, and said companion apparatus number, and sending a first starter message including said first session number, said first cryptotext, and said first hash value to said second key exchange apparatus;
• when said first starter message is received from said first key exchange apparatus, decrypting, by said second CPU, said first cryptotext using information of said first session number and a second private key, generating a second hash value including decrypted result, determining whether the second hash value and said first hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a responder session number which is different from any one of said initial session number and said starter session number, and generating a second session number by adding said responder session number to said first session number;
• generating, by said second CPU, a second cryptotext using information of said second session number and said random number, generating a third hash value including in-formation of said second session number and said second private key, storing an arithmetic result included in said third hash value in said second storage, and sending a responder message including said second session number, said second cryptotext, and said third hash value to said first key exchange apparatus;
• when said responder message is received from said second key exchange apparatus, decrypting, by said first CPU, said second cryptotext using information of said second session number and said first private key, generating a fourth hash value including decrypted result, determining whether the fourth hash value and said third hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a fifth hash value including information of said second session number and said first private key, storing said fifth hash value as a key in said first storage, and sending a second starter message including said second session number and said fifth hash value to said second key exchange apparatus;
• and
• when said second starter message is received from said first key exchange apparatus, determining, by said second CPU, whether a sixth hash value generated using information of said second session number and said fifth hash value are in agreement with each other or not based on a property of a bilinear mapping, and when the hash values are in agreement with each other, generating a sixth hash value using said arithmetic result and information of said second session number, and storing said sixth hash value as a key in said second storage.