Communication system and communication device
First Claim
1. A communication system, comprising:
- a first communication apparatus includingfirst short-range communication means for transmitting an inquiry signal to a short-range external communication apparatus via electromagnetic waves and waiting for a response to the inquiry signal;
first long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the first short-range communication means;
first switching means for switching to the first short-range communication means or the first long-range communication means; and
asymmetric key generating means for generating an encryption key and a decryption key corresponding to the encryption key, the encryption key and the decryption key being asymmetric to each other, anda second communication apparatus includingsecond short-range communication means for receiving the inquiry signal from a short-range external communication apparatus and transmitting a response signal in response to the inquiry signal;
second long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the second short-range communication means;
second switching means for switching to the second short-range communication means or the second long-range communication means;
session key generating means for generating a random number and using the random number to generate a session key; and
encrypting means for encrypting the session key, whereinthe second communication apparatus uses the encryption key transmitted from the first communication apparatus to encrypt the session key into an encrypted session key and transmits the encrypted session key to the first communication apparatus, andthe first communication apparatus uses the decryption key to decrypt the encrypted session key into the session key and transmits to the second communication apparatus a communication switching request signal to request a switching from a short-range communication by the first and second short-range communication means to a long-range communication, with the session key, by the first and second long-range communication means of the first and second communication apparatuses.
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Accused Products
Abstract
A communication apparatus includes a short-range communication unit and a long-range communication unit that communicates via electromagnetic waves in a range wider than a communication area of the short-range communication unit. The communication apparatus further includes a session key generating unit that generates a random number and uses the random number to generate a session key. In addition, the communication apparatus includes an encrypting unit that encrypts the session key. The communication apparatus uses an encryption key transmitted from an external communication apparatus to encrypt the session key into an encrypted session key, transmits the encrypted session key to the external communication apparatus, and receives from the external communication apparatus a communication switching request signal to request a switching from a short-range communication by the short-range communication unit to a long-range communication, with the session key, the long-range communication unit.
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Citations
14 Claims
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1. A communication system, comprising:
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a first communication apparatus including first short-range communication means for transmitting an inquiry signal to a short-range external communication apparatus via electromagnetic waves and waiting for a response to the inquiry signal; first long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the first short-range communication means; first switching means for switching to the first short-range communication means or the first long-range communication means; and asymmetric key generating means for generating an encryption key and a decryption key corresponding to the encryption key, the encryption key and the decryption key being asymmetric to each other, and a second communication apparatus including second short-range communication means for receiving the inquiry signal from a short-range external communication apparatus and transmitting a response signal in response to the inquiry signal; second long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the second short-range communication means; second switching means for switching to the second short-range communication means or the second long-range communication means; session key generating means for generating a random number and using the random number to generate a session key; and encrypting means for encrypting the session key, wherein the second communication apparatus uses the encryption key transmitted from the first communication apparatus to encrypt the session key into an encrypted session key and transmits the encrypted session key to the first communication apparatus, and the first communication apparatus uses the decryption key to decrypt the encrypted session key into the session key and transmits to the second communication apparatus a communication switching request signal to request a switching from a short-range communication by the first and second short-range communication means to a long-range communication, with the session key, by the first and second long-range communication means of the first and second communication apparatuses. - View Dependent Claims (2, 7, 8, 9, 10, 11, 12, 13)
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3. A communication apparatus, comprising:
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short-range communication means for transmitting an inquiry signal to a short-range external communication apparatus via electromagnetic waves and waiting for a response to the inquiry signal; long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the short-range communication means; switching means for switching to the short-range communication means or the long-range communication means; and asymmetric key generating means for generating an encryption key and a decryption key corresponding to the encryption key, the encryption key and the decryption key being asymmetric to each other, wherein the communication apparatus uses the decryption key to decrypt an encrypted session key transmitted from an external communication apparatus and transmits to the external communication apparatus a communication switching request signal to request a switching from a short-range communication by the short-range communication means to a long-range communication, with the session key, by the long-range communication means. - View Dependent Claims (4)
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5. A communication apparatus, comprising:
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short-range communication means for receiving an inquiry signal from a short-range external communication apparatus and transmitting a response signal in response to the inquiry signal; long-range communication means for communicating via electromagnetic waves in a range wider than a communication area of the short-range communication means; switching means for switching to the short-range communication means or the long-range communication means; session key generating means for generating a random number and using the random number to generate a session key; and encrypting means for encrypting the session key, wherein the communication apparatus uses an encryption key transmitted from an external communication apparatus to encrypt the session key into an encrypted session key, transmits the encrypted session key to the external communication apparatus, and receives from the external communication apparatus a communication switching request signal to request a switching from a short-range communication by the short-range communication means to a long-range communication, with the session key, by the long-range communication means. - View Dependent Claims (6)
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14. A communication apparatus, comprising:
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a short-range communication unit configured to receive an inquiry signal from a short-range external communication apparatus and to transmit a response signal in response to the inquiry signal; a long-range communication unit configured to communicate via electromagnetic waves in a range wider than a communication area of the short-range communication unit; a switching unit configured to switch to the short-range communication unit or the long-range communication unit; a session key generating unit configured to generate a random number and to use the random number to generate a session key; and an encrypting unit configured to encrypt the session key, wherein the communication apparatus uses an encryption key transmitted from an external communication apparatus to encrypt the session key into an encrypted session key, transmits the encrypted session key to the external communication apparatus, and receives from the external communication apparatus a communication switching request signal to request a switching from a short-range communication by the short-range communication unit to a long-range communication, with the session key, the long-range communication unit.
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Specification