Source: https://patents.google.com/patent/CN102144370B/en
Timestamp: 2020-04-03 02:36:18
Document Index: 532649175

Matched Legal Cases: ['art 16', 'art 16', 'art 1', 'art 1', 'art 2', 'art 2', 'art 1', 'art 2', 'art 124', 'art 125', 'art 126', 'art 124', 'art 126', 'art 126', 'art 126', 'art 117', 'art 117', 'art 117', 'art 126', 'art 117', 'art 126', 'art 126', 'art 126', 'art 126', 'art 126', 'art 126', 'art 126', 'art 126', 'art 126', 'art 124', 'art 124', 'art 124', 'art 125', 'art 125', 'art 125', 'art 126', 'art 126', 'art 126', 'art 126', 'art 117', 'art 117', 'art 126', 'art 126', 'art 224', 'art 225', 'art 226', 'art 125', 'art 225', 'art 126', 'art 126', 'art 125', 'art 126', 'art 126', 'art 126', 'art 126', 'art 124', 'art 226', 'art 226', 'art 225', 'art 226', 'art 217', 'art 226', 'art 217', 'art 217', 'art 217', 'art 217', 'art 226', 'art 226', 'art 226', 'art 217', 'art 226', 'art 226', 'art 226', 'art 226', 'art 226', 'art 226', 'art 225', 'art 125', 'art 225', 'art 125', 'art 225', 'art 226', 'art 226', 'art 226', 'art 226', 'art 226', 'art 226', 'art 225', 'art 2', 'art\n3']

CN102144370B - Transmitting device, receiving device, transmitting method and receiving method - Google Patents
Transmitting device, receiving device, transmitting method and receiving method Download PDF
CN102144370B
CN102144370B CN200880130952.8A CN200880130952A CN102144370B CN 102144370 B CN102144370 B CN 102144370B CN 200880130952 A CN200880130952 A CN 200880130952A CN 102144370 B CN102144370 B CN 102144370B
CN200880130952.8A
CN102144370A (en
奥田将人
2008-09-04 Application filed by 富士通株式会社 filed Critical 富士通株式会社
2008-09-04 Priority to PCT/JP2008/065977 priority Critical patent/WO2010026637A1/en
2011-08-03 Publication of CN102144370A publication Critical patent/CN102144370A/en
2015-04-15 Publication of CN102144370B publication Critical patent/CN102144370B/en
The volume of communication is suppressed in the case where an encrypted data packet is transmitted and received. A transmitting device (1) is provided with an encryption unit (1a) and a transmitting unit (1b). The encryption unit (1a) encrypts each of data packets (3a, 3b) based on a frame number (3c) and a predetermined encryption key. The transmitting unit (1b) transmits a frame (3) including encrypted data packets (3a, 3b). A receiving device (2) is provided with a receiving unit (2a) and a decoding unit (2b). The receiving unit (2a) receives the frame (3). The decoding unit (2b) decodes each of the data packets (3a, 3b) based on a frame number (3c) of the frame (3) and a predetermined decryption key.
Dispensing device, receiving system, sending method and method of reseptance
The present invention relates to dispensing device, receiving system, sending method and method of reseptance.
At present, be widely utilized with the packet communication being grouped into unit transceiving data.In packet communication, in order to ensure confidentiality and the fail safe of data, can be encrypted to be grouped into unit.Such as, in IP (InternetProtocol) packet communication field, the technology (for example, referring to non-patent literature 1) being called as IPsec that existence shared key cipher mode is encrypted IP packet and sends.Further, in the field of fixed radio communication or mobile radio telecommunications, the technology (for example, referring to non-patent literature 2,3) that also existence shared key mode is encrypted packet.
In addition, packet can in the next communication layers, and the frame be mapped to as regulation communication unit sends.Such as, in wireless communications, in physical layer, packet can be mapped to radio frames.One or more packet can be comprised in frame.
Non-patent literature 1:Internet Engineering Task Force (IETF), " Using AdvancedEncryption Standard (AES) CCM Mode with IPsec Encapsulating Security Payload (ESP) ", RFC 4309.
Non-patent literature 2:The Institute of Electrical and Electronics Engineers (IEEE), " IEEEStandard for Local and Metropolitan Area Networks Part 16:Air Interface for FixedBroadband Wireless Access Systems ", IEEE 802.16-2004.
Non-patent literature 3:The Institute of Electrical and Electronics Engineers (IEEE), " IEEEStandard for Local and Metropolitan Area Networks Part 16:Air Interface for Fixed andMobile Broadband Wireless Access Systems ", IEEE 802.16e-2005.
But, in encryption method, there is the method also using except encryption key and be called as the bit string of initialization vector.Even if plaintext (data before encryption) is identical and encryption key is identical, if use different initialization vectors, then different ciphertexts (data after encryption) can be obtained.That is, by using initialization vector, can suppress to reuse identical encryption key and the decline of fail safe that causes.
About this point, in the technology recorded in above-mentioned non-patent literature 1 ~ 3, the initialization vector that transmitter side uses shared key and generates according to each packet, is encrypted each packet.Further, the information (such as, the bit string of 4 bytes) relevant with the initialization vector used in encryption to be attached in the packet of encryption and to send by transmitter side.But, in the method, there is the encryption of traffic companion data grouping and the problem that increases.
The present invention proposes in view of the above problems, its object is to, and provides a kind of dispensing device of the traffic, receiving system, sending method and method of reseptance when can suppress the packet after receiving and dispatching encryption.
In order to solve the problem, a kind of dispensing device is provided, it sends the frame comprising more than one packet, it is characterized in that, described dispensing device has: encryption unit, it generates initialization vector according to the frame number of described frame used in the transmission of described packet, and according to the encryption key of generated described initialization vector and regulation, is encrypted respectively to described packet, and sending part, it sends the described frame comprising the described packet after being encrypted by described encryption unit, in the generation of described initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, in the described cycle period of the bit string of described encryption unit after each described degeneracy or the bit string after described expansion, change described encryption key.
Further, in order to solve the problem, a kind of receiving system is provided.This receiving system has acceptance division, and its receiving package is containing the frame of more than one encrypted packet, and decryption part, it generates initialization vector according to the frame number of the described frame received by described acceptance division, and according to the decruption key of generated described initialization vector and regulation, respectively the described packet be included in described frame is decrypted, in the generation of described initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, in the described cycle period of the bit string of described decryption part after each described degeneracy or the bit string after described expansion, change described decruption key.
Further, in order to solve the problem, provide a kind of sending method of dispensing device, it sends the frame comprising more than one packet.In this sending method, generate initialization vector according to the frame number of the described frame used in the transmission of described packet, and according to the encryption key of generated described initialization vector and regulation, respectively described packet is encrypted, and send the described frame comprising encrypted described packet, in the generation of described initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, be changed in the described cycle period of the bit string of described encryption key after each described degeneracy or the bit string after described expansion
Further, in order to solve the problem, a kind of method of reseptance of receiving system is provided.In this method of reseptance, receiving package is containing the frame of more than one encrypted packet, frame number according to received described frame generates initialization vector, and according to the decruption key of generated described initialization vector and regulation, respectively the described packet be included in described frame is decrypted, in the generation of described initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, be changed in the described cycle period of the bit string of described decruption key after each described degeneracy or the bit string after described expansion.
And, in order to solve the problem, a kind of communication means is provided, the method is the communication means of mobile communication system, this mobile communication system has the 1st base station and the 2nd base station that the frame comprising more than one packet are sent to travelling carriage, it is characterized in that, this communication means comprises: described 1st base station generates the 1st initialization vector of the 1st value comprising value and the regulation generated according to the frame number of the described frame defined by described 1st base station, and encryption key according to the rules and described 1st initialization vector that generates, described packet is encrypted, and send the described frame comprising encrypted described packet, the communication object of described travelling carriage is switched to described 2nd base station from described 1st base station, described 2nd base station generates the 2nd initialization vector of the 2nd value comprising value and the regulation different from described 1st value generated according to the frame number of the described frame defined by described 2nd base station, and according to the encryption key of described regulation and described 2nd initialization vector that generates, described packet is encrypted, and send the described frame comprising encrypted described packet, in the generation of described 1st initialization vector and described 2nd initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, be changed in the described cycle period of the bit string of described encryption key after each described degeneracy or the bit string after described expansion.
In addition, in order to solve the problem, another kind of communication means is also provided, the method is the communication means of travelling carriage, the frame comprising more than one packet is sent to the 1st base station or the 2nd base station by this travelling carriage, it is characterized in that, generate the 1st initialization vector of the 1st value comprising value and the regulation generated according to the frame number of the described frame defined by described 1st base station, and encryption key according to the rules and described 1st initialization vector that generates, described packet is encrypted, and the described frame comprising encrypted described packet is sent to described 1st base station, communication object is switched to described 2nd base station from described 1st base station, generate the 2nd initialization vector of the 2nd value comprising value and the regulation different from described 1st value generated according to the frame number of the described frame defined by described 2nd base station, and according to the encryption key of generated described 2nd initialization vector and described regulation, described packet is encrypted, and the described frame comprising encrypted described packet is sent to described 2nd base station, in the generation of described 1st initialization vector and described 2nd initialization vector, can select be using degeneracy after bit string as the part of initialization vector, or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number, the quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter, be changed in the described cycle period of the bit string of described decruption key after each described degeneracy or the bit string after described expansion.
According to above-mentioned dispensing device, receiving system, sending method, method of reseptance and communication means, traffic when receiving and dispatching encrypted packet can be suppressed.
Fig. 1 is the figure representing dispensing device and receiving system.
Fig. 2 is the figure of the system configuration representing mobile communication system.
Fig. 3 is the block diagram representing base station.
Fig. 4 is the block diagram representing travelling carriage.
Fig. 5 is the figure of the 1st structure example representing key management table.
Fig. 6 is the figure of the structure example representing radio frames.
Fig. 7 is the figure of the 1st form example representing MAC-PDU.
Fig. 8 is the figure of the 2nd form example representing MAC-PDU.
Fig. 9 is the sequential chart of the flow process representing control message.
Figure 10 is the flow chart representing grouping transmission processing.
Figure 11 is the figure of the 1st example representing initialization vector.
Figure 12 is the figure of the example representing encryption method.
Figure 13 represents that grouping receives the flow chart of process.
Figure 14 is the figure of the example representing decryption method.
Figure 15 is the 1st flow chart representing key updating process.
Figure 16 is the figure of the 2nd structure example representing key management table.
Figure 17 is the figure of the 2nd example representing initialization vector.
Figure 18 is the sequential chart of the flow process representing switching controls.
Figure 19 is the figure of the 3rd structure example representing key management table.
Figure 20 is the 2nd flow chart representing key updating process.
By the accompanying drawing representing preferred implementation as example of the present invention and the following explanation be associated, can clearer above-mentioned and other object of the present invention, feature and advantage.
Below, present embodiment is described in detail with reference to accompanying drawing.
Fig. 1 is the figure representing dispensing device and receiving system.Dispensing device 1 transmission frame 3, receiving system 2 is from dispensing device 1 received frame 3.More than one packet can be comprised in frame 3.In the example in fig 1, frame 3 comprises packet 3a, 3b.
Dispensing device 1 has encryption unit 1a and sending part 1b.Encryption unit 1a is encrypted packet 3a, 3b respectively.The encryption key that encryption uses dispensing device 1 to hold.Encryption key is such as the key corresponding with the decruption key that receiving system 2 is held.Further, in encryption, the frame number 3c of the frame 3 used in the transmission of packet 3a, 3b is used in.Frame number 3c such as uses in the generation of initialization vector.Sending part 1b sends the frame 3 comprising packet 3a, the 3b encrypted by encryption unit 1a.
Receiving system 2 has acceptance division 2a and decryption part 2b.Acceptance division 2a is from dispensing device 1 received frame 3.Decryption part 2b is decrypted packet 3a, 3b of being included in the frame 3 that received by acceptance division 2a respectively.In deciphering, use the decruption key that receiving system 2 is held.Decruption key is such as the key corresponding with the encryption key that dispensing device 1 is held.Further, in deciphering, the frame number 3c of the frame 3 used in the transmission of packet 3a, 3b is used in.Frame number 3c such as uses in the generation of initialization vector.
Herein, frame number 3c is the numbering identifying each frame, such as, defined by dispensing device 1 or receiving system 2.For frame number 3c, the serial number each frame being increased one by one to 1 can be used.Can think that frame number 3c is included in frame 3.Now, receiving system 2 can extract frame number 3c from frame 3, for deciphering.But receiving system 2 manages current frame number, and also can be decrypted according to the frame number by this device management.
Further, as cryptographic algorithm, dispensing device 1 and receiving system 2 can use shared key cipher mode or public key encryption mode.As shared key cipher mode, such as, can expect DES (Data Encryption Standard) or AES (Advanced Encryption Standard).When shared key cipher mode, the encryption key of dispensing device 1 and the decruption key of receiving system 2 are identical keys (shared key).On the other hand, when public key encryption mode, the encryption key of dispensing device 1 and the decruption key of receiving system 2 are different keys (PKI and private key).When shared key cipher mode, the shared key that dispensing device 1 and receiving system 2 prearrange use as encryption key/decruption key.
Further, dispensing device 1 and receiving system 2 regularly or irregularly can change encryption key/decruption key.Particularly, (such as, one by one 1 is being increased to each frame, and the next one of the maximum that can show gets back to the situation of minimum value) when frame number circulates with specified period, from the view point of the fail safe of encryption, preferably at least change a secondary key according to each cycle period.Further, dispensing device 1 and receiving system 2 also according to encryption and the number of data packets of deciphering, can change key.
Further, encrypted packet can also be made and do not have encrypted packet to mix in frame 3.Further, although can expect that dispensing device 1 and receiving system 2 carry out situation about communicating one to one in above-mentioned, also can expect that dispensing device 1 sends the situation of packet to multiple receiving system 2.Now, in frame 3, the packet on ground for the purpose of multiple receiving system 2 also can be made to mix.Further, also can expect that multiple dispensing device 1 sends the situation of packet to receiving system 2.Now, in frame 3, the packet from multiple dispensing device 1 also can be made to mix.
Further, in the encryption and deciphering of packet, except encryption key/decruption key and frame number 3c, the index of the position representing this packet in frame 3 can be used in further.Index such as represents that this packet is the numbering of which packet in frame 3.Can expect according to frame number 3c and index, generate initialization vector.In addition, index also can be attached to packet 3a, 3b to send by dispensing device 1 respectively.
Further, in encryption and decryption, also can expect that the part only extracting the bit string representing frame number 3c uses.Further, the bit string that use obtains the bit string additional extension position of expression frame number 3c can also be expected.The expansion of the bit string of such expression frame number 3c or degeneracy, when with effective especially when the periodic change different from the cycle period of frame number 3c encryption key/decruption key.In addition, frame number 3c or above-mentioned index, also can use with the purposes beyond the generation of initialization vector.Such as, also can will combine the bit string of encryption key/decruption key and frame number 3c, use as temporary transient encryption key/decruption key.
According to such dispensing device 1, by encryption unit 1a according to the frame number 3c of the frame 3 used in this transmission and encryption key, packet 3a, 3b are encrypted respectively.Further, the frame 3 containing encrypted packet 3a, 3b is sent by sending part 1b.Further, according to such dispensing device 2, by the frame 3 of receiving system 2a receiving package containing packet 3a, 3b.Further, by decryption part 2b according to the frame number 3c of received frame 3 and decruption key, respectively packet 3a, 3b of being included in frame 3 are decrypted.
Thus, dispensing device 1 also can not using as the information beyond decruption key, information that receiving system 2 uses in order to decrypt data packets 3a, 3b, be attached to packet 3a, 3b respectively to send.The frame number 3c of the frame 3 that receiving system 2 can use from the transmission at packet 3a, 3b, obtains the information used in deciphering beyond decruption key.Therefore, inhibit the increase of the traffic of companion data grouping 3a, 3b encryption.
Below, the situation above-mentioned sending method and method of reseptance being applied to mobile communication system is further described.But above-mentioned sending method and method of reseptance, also can be applied to the communication system of other kinds such as fixed wireless communications system or wired communication system.And, in mobile communication system shown below, although the communication (uplink communication) from travelling carriage to base station and (downlink communication) both sides that communicate from base station to travelling carriage, carry out the encryption of packet, also can only be encrypted in any one party.
Fig. 2 is the figure of the system configuration representing mobile communication system.The mobile communication system of the 1st execution mode has base station 100,100a and travelling carriage 200,200a.
Base station 100,100a are when travelling carriage 200,200a belong in the community of base station 100,100a, can carry out the radio communication device of packet communication with travelling carriage 200,200a.Base station 100,100a, by down link (from base station 100,100a to the wireless link in travelling carriage 200,200a direction), send packet to travelling carriage 200,200a.Further, base station 100,100a by up link the wireless link of 100a direction (from travelling carriage 200, the 200a to base station 100), the packet that receiving mobile 200,200a send.In addition, base station 100 and base station 100a via not shown upper station (such as, radio network control apparatus), can communicate mutually.But, base station 100 also can be made directly to communicate with base station 100a.
Travelling carriage 200,200a can carry out the wireless terminal device of packet communication with base station 100,100a.Travelling carriage 200,200a are such as portable telephones.Travelling carriage 200,200a are by up link, and to base station 100,100a sends packet.Further, travelling carriage 200,200a are by down link, and from base station 100,100a receives the packet on ground for the purpose of travelling carriage 200,200a.In addition, in the 1st execution mode, consider that travelling carriage 200 is positioned at the situation of the community of base station 100.
Herein, base station 100,100a and travelling carriage 200,200a can in order to ensure the confidentiality of data and integrality, and is encrypted packet and sends.When considering down link, base station 100,100a are equivalent to the dispensing device 1 of Fig. 1, and travelling carriage 200,200a are equivalent to the receiving system 2 of Fig. 1.Further, when considering up link, travelling carriage 200,200a are equivalent to dispensing device 1, and base station 100,100a are equivalent to receiving system 2.
As encryption mode, in the present embodiment, the situation using AES-CCM (Counter with CBCMAC) is considered.In AES-CCM, as cryptographic algorithm, be used as the AES of shared key cipher mode.Further, as encryption Land use models, count mode (CTR pattern) is used.And then, packet will be attached to by the verify data (MAC:Message AuthenticationCode) of CBC (password packet train, Cipher Block Chaining) schema creation.For the particular content of AES-CCM, will illustrate afterwards.But base station 100,100a and travelling carriage 200,200a also can use the encryption mode beyond AES-CCM.
Fig. 3 is the block diagram representing base station.Base station 100 has antenna 111, antenna diplexer 112, acceptance division 113, demodulation section 114, lsb decoder 115, control information extraction unit 116, grouping reproducing unit 117, network interface 118, packet identification portion 119, packet buffer 120, PDU generating unit 121, coding unit 122, modulation portion 123, sending part 124, table storage part 125 and control part 126.In addition, base station 100a also can be realized by the modular structure identical with base station 100.
Antenna 111 is sending/receiving common antenna.The wireless signal received from travelling carriage 200,200a is outputted to antenna diplexer 112 by antenna 111.Further, the transmission signal that obtains from antenna diplexer 112 of the wireless output of antenna 111.But, also can transmission antenna and antenna for receiving be set respectively.
Antenna diplexer 112 becomes sending/receiving common antenna to make antenna 111, and is separated Received signal strength and sends signal.The Received signal strength obtained from antenna 111 is outputted to acceptance division 113 by antenna diplexer 112.Further, the transmission signal wireless obtained from sending part 124 is outputted to antenna 111.In order to be separated Received signal strength and send signal, antenna diplexer 112 such as has band pass filter (BPF:Band Pass Filter).
The Received signal strength obtained from antenna diplexer 112 is converted to digital baseband signal by acceptance division 113, and outputs to demodulation section 114.In order to carry out this conversion process, acceptance division 113 such as has: low noise amplifier (LNA:Low Noise Amplifier), frequency converter, BPF, A/D (Analog to Digital, modulus) transducer, quadrature demodulator etc.
Demodulation section 114 carries out demodulation to the digital baseband signal obtained from acceptance division 113.In demodulation, the demodulation mode using regulation or the demodulation mode of being specified by control part 126.Further, obtained restituted signal is outputted to lsb decoder 115 by demodulation section 114.
Lsb decoder 115 is decoded to the restituted signal obtained from demodulation section 114.Such as, lsb decoder 115 pairs of restituted signals carry out the process such as deinterleaving, error correction decoding, error detection.In decoding, the decoding process using regulation decoding process or specified by control part 126.Further, obtained decoded data is outputted to control information extraction unit 116 by lsb decoder 115.
Control information extraction unit 116 by extracting the control information generated by travelling carriage 200,200a in the decoded data obtained from lsb decoder 115, and outputs to control part 126.The SBC-REQ (Subscriber station Basic Capability-REQuest) of the communication capacity for notifying travelling carriage 200,200a, the PKM-REQ (Privacy Key Management-REQuest) etc. of shared key for looking for novelty such as is comprised in control information.Further, control information extraction unit 116 extracts user data by the decoded data obtained from lsb decoder 115, and outputs to grouping reproducing unit 117.
Grouping reproducing unit 117 obtains user data from control information extraction unit 116, and the conversion of data mode is carried out from the data mode being called as MAC-PDU (Medium Access Control-Protocol Data Unit) used between radio zone, be converted to the block form used between upper station-base station.Now, as required, combination or the segmentation of MAC-PDU can also be carried out.Further, packet is outputted to network interface 118 by reproducing unit 117 of dividing into groups.
Herein, reproducing unit 117 of dividing into groups has decryption part 117a.When there is the MAC-PDU of encryption, decryption part 117a is decrypted this MAC-PDU.Now, decryption part 117a obtains from control part 126 and includes the frame number of the radio frames of the MAC-PDU that will decipher, the index representing the position of this MAC-PDU in radio frames and shared key (decruption key).Further, decryption part 117a is decrypted MAC-PDU according to the information obtained from control part 126.For the particular content of decryption method, will illustrate afterwards.
Network interface 118 is for carrying out the communication interface of packet communication with upper station.The packet obtained from grouping reproducing unit 117 is sent to upper station by network interface 118.Further, the packet obtained from upper station is outputted to packet identification portion 119 by network interface 118.
The packet obtained from network interface 118 is outputted to packet buffer 120 by packet identification portion 119.Now, packet identification portion 119, by from the destination-address (such as, destination IP (Internet Protocol) address) in the head being included in packet, determines destination travelling carriage.The identifying information of address and travelling carriage such as can be mapped by packet identification portion 119 and to carry out managing and realize by this.Further, the QoS (Quality of Service) corresponding with determined travelling carriage is judged.Further, packet identification portion 119 specifies the size of travelling carriage, QoS and packet, carries out band allocation request to control part 126.
Packet buffer 120 is the buffer storage temporarily storing the packet obtained from packet identification portion 119.Stored packet, according to the instruction from control part 126, is outputted to PDU generating unit 121 by packet buffer 120 successively.In addition, storage area, owing to carrying out management data grouping according to destination or QoS, therefore also can be divided into multiple region by packet buffer 120 in advance.Further, packet buffer 120 also can have multiple storage arrangement.
PDU generating unit 121, while the packet obtaining user data from packet buffer 120, obtains control information from control part 126.Such as include the response (Response) etc. corresponding with SBC-REQ or PKM-REQ in the control information.Packet is converted to MAC-PDU form by PDU generating unit 121, and carries out controlling user data and control information are suitably configured in radio frames.Now, as required, combination or the segmentation of packet can also be carried out.Further, MAC-PDU and control information are outputted to coding unit 122 by PDU generating unit 121.
Herein, PDU generating unit 121 has encryption unit 121a.Encryption unit 121a, according to the instruction from control part 126, is encrypted packet.Now, encryption unit 121a obtains the frame number of the radio frames used the transmission of encrypted MAC-PDU, the index representing the position of this MAC-PDU in radio frames and shared key (encryption key) from control part 126.Further, encryption unit 121a is encrypted packet according to the information obtained from control part 126.For the particular content of encryption method, will illustrate afterwards.
Coding unit 122 is encoded to the MAC-PDU obtained from PDU generating unit 121.Such as, coding unit 122 couples of MAC-PDU carry out the process such as additional, error correction coding, the intertexture of error detection parity.In coding, the coded system using regulation or the coded system of being specified by control part 126.Further, obtained coded data is outputted to modulation portion 123 by coding unit 122.
Modulation portion 123 is modulated the coded data obtained from coding unit 122.In modulation, the modulation system using regulation or the modulation system of being specified by control part 126.Such as, modulation portion 123 carries out the digital modulation such as QPSK (QuadraturePhase Shift Keying, orthogonal PSK) or 16QAM (Quadrature amplitude modulation, quadrature amplitude modulation).Further, obtained digital baseband signal is outputted to sending part 124 by modulation portion 123.
The digital baseband signal obtained from modulation portion 123 is converted to the transmission signal for wireless transmission by sending part 124, and outputs to antenna diplexer 112.In order to carry out this conversion process, sending part 124 such as has quadrature modulator, D/A (Digital to Analog, digital-to-analogue) transducer, frequency converter, BPF, power amplifier etc.
Table storage part 125 stores the key management table for managing the shared key (being encryption key and decruption key) used in the communication of travelling carriage 200,200a.Further, the various information that use in Control on Communication such as assignment information that storage part 125 goes back storing mobile station 200, the information of communication capacity of 200a, authentication information, QoS information, Radio Resource are shown.The information stored by the suitable reference/updating form storage part 125 of control part 126.
Control part 126 entirety controls the radio communication of carrying out with travelling carriage 200,200a.Such as, control part 126 manages the frame number of radio frames.Further, the renewal of the shared key used in the communication carried out with travelling carriage 200,200a is also managed.Control part 126 when decryption part 117a is decrypted encrypted MAC-PDU, to decryption part 117a notification frame numbering, index and shared key.Further, when encryption unit 121a is encrypted packet, to encryption unit 121a notification frame numbering, index and shared key.In addition, identical shared key can be used in up link and down link, also can use different shared keys.
Further, when there is band allocation request from packet identification portion 119, control part 126 according to QoS to travelling carriage 200,200a distributing radio resource.Further, according to allocation result, instruction packet buffer 120 exports packet.Control part 126, according to the control information obtained from control information extraction unit 116, carries out various control as above.Further, generate control information as required, and output to PDU generating unit 121.
Fig. 4 is the block diagram representing travelling carriage.Travelling carriage 200 has antenna 211, antenna diplexer 212, acceptance division 213, demodulation section 214, lsb decoder 215, control information extraction unit 216, grouping reproducing unit 217, data processing division 218, packet identification portion 219, packet buffer 220, PDU generating unit 221, coding unit 222, modulation portion 223, sending part 224, table storage part 225 and control part 226.In addition, travelling carriage 200a also can be realized by the modular structure same with travelling carriage 200.
The function of the module in above-mentioned module except data processing division 218 is identical with the function of the module of the same name that above-mentioned base station 100 has.But in the mobile communication system of present embodiment, the allocation manager being set to Radio Resource is carried out in base station side.Therefore, travelling carriage 200 uses the Radio Resource distributed by base station 100,100a to carry out uplink communication.Owing to accepting the distribution of Radio Resource, therefore such as travelling carriage 200 pairs of base stations 100,100a send the control information representing band request.
Data processing division 218 uses the packet obtained from grouping reproducing unit 217, carries out the various data processing such as Graphics Processing or voice output process.Further, when producing the data that will send, data processing division 218 generates packet, and adds destination-address and output to packet identification portion 219.
In addition, travelling carriage 200 only can communicate with any one base station in each timing, also can communicate with multiple base station parallel.Further, travelling carriage 200 can only set a link (connection) to a base station, also can to a multiple link of base station sets.Such as link to each the shared key preparing to use in the encryption and deciphering of packet.Now, key management is carried out to each link.
Fig. 5 is the figure of the 1st structure example representing key management table.Key management table 125a is stored in the table storage part 125 of base station 100.Also the table same with key management table 125a is stored in the table storage part 225 of travelling carriage 200.The project representing CID (Connection IDentifier), shared key and index is set with in key management table 125a.Projects, in transversely arranged information, associate each other.
In the project representing CID, be set with the identifier being distributed to travelling carriage 200,200a when linking setting by base station 100,100a.Sometimes also to a multiple CID of mobile assignment.
In the project representing shared key, be set with and representing the shared key (being encryption key and decruption key) used in the link of CID.Shared key is the bit string of the specific lengths such as such as 16 bytes (128 bit).The bit length of shared key decides according to used cryptographic algorithm.
In the project representing index, each radio frames setting is used to the number of times of this shared key.Index is the bit string of the specific lengths such as such as 1 byte (8 bit).Each radio frames is being initialized as 0 at every turn, and when using this shared key to be encrypted packet, is making index delta.In addition, also can replace each shared key index of definition, and the index unique to the definition of multiple shared key entirety.
The information of key management table 125a is suitably upgraded by control part 126.Such as, in key management table 125a, be registered with the information that CID is " 1 ", shared key is " Key#a ", index is " 0 ".This represents in certain radio frames, and do not use shared key Key#a, namely the packet no one of the link of CID=1 is encrypted.In addition, such as the table as key management table 125a is prepared respectively to up link and down link.
Fig. 6 is the figure of the structure example representing radio frames.Radio frames shown in Fig. 6 uses in the radio communication between base station 100,100a and travelling carriage 200,200a.In the mobile communication system of present embodiment, realize uplink communication and downlink communication by time division duplex (TDD:Time Division Duplex) mode.That is, be two time domains by each wireless frame segmentation, using first half section as the DL subframe used in downlink communication, using the second half section as the UL subframe used in uplink communication.But, also can realize uplink communication and downlink communication by Frequency Division Duplexing (FDD) (FDD:Frequency Division Duplex) mode.
When this example, in DL subframe, first as the known signal of the beginning for identifying radio frames, send preamble.Then, after preamble, the FCH (Frame ControlHeader, frame control head) in the region representing DL-MAP is sent.Then, after FCH, DL-MAP is sent.DL-MAP comprises the allocation of radio resources of DL subframe to the information of the allocation situation of each travelling carriage.Then, after DL-MAP, UL-MAP is sent.The allocation of radio resources of UL subframe be comprised to the information of the allocation situation of each travelling carriage in UL-MAP.
Further, in DL-MAP, also comprise the frame number of this radio frames.Frame number is such as the bit string of the specific lengths such as 3 bytes (24 bit).Continuous print frame number is given with ascending order in a series of radio frames.Frame number circulates with specified period.Such as, when reaching the maximum that can show with 24 bits, the frame number of next radio frames gets back to zero.In addition, also the DL-MAP of whole radio frames can carry out transmission frame numbering, and can intermittently send.If this is owing to giving frame number with the rule of regulation, then can estimate the frame number of current radio frames according to the frame number of past notice.
Then, after UL-MAP, the set of user data and control information is sent as DL-Burst (DL-burst).In DL-Burst, more than one MAC-PDU can be comprised.In addition, the MAC-PDU of encryption and unencrypted MAC-PDU also can be made to mix.The destination of each MAC-PDU can be determined according to the CID be included in the head of DL-MAP or MAC-PDU.
In the UL sub-frame, the ranging region for sending ranging code is provided with.In ranging region, travelling carriage 200,200a can not be subject to the license of base station 100,100a and send.Ranging region such as can link set up before communication or band request, handover request etc. in use.
Further, UL-Burst region is provided with in the UL sub-frame.The set of user data and control information in the region distributing to this travelling carriage 200,200a self, can send as UL-Burst by travelling carriage 200,200a.In UL-Burst, more than one MAC-PDU can be included.In addition, the MAC-PDU of encryption and unencrypted MAC-PDU also can be made to mix.
In addition, from during DL subframe is to UL subframe, the blank time being called as TTG (Transmit/ReceiveTransition Gap, transmission/reception change gap) is inserted with.Further, from during UL subframe is to next DL subframe, the blank time being called as RTG (Receive/Transmit Transition Gap receives/transmission change gap) is inserted with.
Fig. 7 is the figure of the 1st form example representing MAC-PDU.This MAC-PDU has been implemented encryption.In the 1st form example, include ICV (the Integrity CheckValue of the head of 6 bytes, encrypted pay(useful) load, 8 bytes, data integrity value) and the CRC (Cyclic Redundancy Check, cyclic redundancy check (CRC)) of 4 bytes.
Head is information additional in order to encapsulate packet in the mac layer.The HCS (Header Check Sequence, head verification sequence) of 1 byte for error detection is included in head.Pay(useful) load is the part be encrypted the content of packet, its variable-length.ICV is the certification data generated by the content of the packet before encrypting.At receiver side, use ICV can check that packet is with or without altering.ICV can encrypt in the same manner as pay(useful) load, but also can not encrypt.CRC is the bit string of the mistake for detecting MAC-PDU entirety additional in the mac layer.
Fig. 8 is the figure of the 2nd form example representing MAC-PDU.MAC-PDU shown in this MAC-PDU and Fig. 7 is same, has been performed encryption.In the 2nd form example, comprise the head of 6 bytes, the index of 1 byte, encrypted pay(useful) load, the ICV of 8 bytes and the CRC of 4 bytes.
The meaning of head, pay(useful) load, ICV and CRC is identical with above-mentioned 1st form example.The meaning of index is as described in above-mentioned key management table 125a.That is, by representing that this MAC-PDU is the numbering of which encrypted MAC-PDU in radio frames, MAC-PDU is attached to.By to MAC-PDU additional index, thus the storage order of the MAC-PDU in radio frames need not be considered at receiver side, and can be decrypted each MAC-PDU.
In addition, in the uplink, travelling carriage 200,200a generate MAC-PDU as above and send, and are received by base station 100,100a and be decrypted.Further, in the downlink, base station 100,100a generate MAC-PDU as above and send, and are received by travelling carriage 200,200a and be decrypted.But, also can omit ICV.
Then, illustrate at the particular content with the process performed in the mobile communication system of structure described above.First, the flow process of the control message between base station 100,100a and travelling carriage 200,200a is described.Then, encryption and the decryption processing of packet are described.Afterwards, the update process of encryption key is described.
Fig. 9 is the sequential chart of the flow process representing control message.Herein, consider that travelling carriage 200 is connected to the situation of base station 100.Below, along the process shown in number of steps key diagram 9.
[step S11] travelling carriage 200 will represent that the control information (SBC-REQ) of self communication ability is sent to base station 100.In SBC-REQ, the cryptography information that travelling carriage 200 can use can be comprised.Travelling carriage 200 such as sends SBC-REQ with the UL-Burst of radio frames.
The control information (SBC-RSP) represented for the response of SBC-REQ is sent to travelling carriage 200 by [step S12] base station 100.In SBC-RSP, the appointed information of used cryptographic algorithm can be comprised.Further, the information that the MAC-PDU of encryption be addition of to what information (such as, whether additional index) can also be comprised.Base station 100 such as sends SBC-RSP with the DL-Burst of radio frames.
The control information (PKM-REQ) that shared key is distributed in request, after the setting linked, is sent to base station 100 by [step S13] travelling carriage 200.Travelling carriage 200 such as sends PKM-REQ with the UL-Burst of radio frames.
[step S14] base station 100 generates shared key and is registered in table.Further, base station 100 comprises shared key and is sent to travelling carriage 200 in expression is for the control information (PKM-RSP) of the response of PKM-REQ.In PKM-RSP, the information of valid period can also be comprised.When have passed through the valid period from the distributing of shared key, it is invalid that this shared key becomes.Base station 100 such as sends PKM-RSP with the DL-Burst of radio frames.
The shared key received from base station 100 is registered in table by travelling carriage 200.Further, travelling carriage 200 stores the frame number including the radio frames of PKM-RSP.This frame number is to judge to upgrade the timing of shared key and reference.Afterwards, travelling carriage 200 uses the shared key be registered in table, communicates with base station 100.In addition, also the shared key of up link and the shared key of down link can be prepared respectively.
[step S15] travelling carriage 200 is when being judged as the timing upgrading shared key, same with step S13, and the PKM-REQ that shared key is distributed in request is sent to base station 100.In addition, for the timing of key updating, will describe in detail afterwards.
[step S16] base station 100 is same with step S14, while updating form in generation shared key, comprises shared key and be sent to travelling carriage 200 in PKM-RSP.Travelling carriage 200 uses the shared key received from base station 100 to carry out updating form.Afterwards, travelling carriage 200 uses the shared key after upgrading, and communicates with base station 100.
Thus, base station 100 and travelling carriage 200 are when linking setting, the reach an agreement on cryptographic algorithm and the information additional to MAC-PDU that use.Further, shared key, according to the request from travelling carriage 200, is distributed in base station 100.Afterwards, base station 100 and travelling carriage 200 regularly or irregularly change shared key.
In addition, in said sequence, although shared key is distributed according to the request from travelling carriage 200 in base station 100, also according to the request from base station 100, the shared key that travelling carriage 200 uses can be determined.Further, even without the request from travelling carriage 200, shared key also automatically can be distributed in base station 100.
Figure 10 is the flow chart representing grouping transmission processing.Herein, consider that base station 100 sends the situation of MAC-PDU.But the situation that travelling carriage 200 carries out sending is also identical.Below, along number of steps, the process shown in Figure 10 is described.
[step S21] control part 126 determines the frame number of next radio frames that will send.
The index of the key management table 125a being stored in table storage part 125 is all initialized as zero by [step S22] control part 126.
[step S23] control part 126 judges whether the packet sent by next radio frames remains in packet buffer 120.When there is remaining packet, process enters into step S24.When not having remaining packet, process enters into step S28.
[step S24] PDU generating unit 121 obtains packet from packet buffer 120, and determines the CID corresponding with the destination of packet.Encryption unit 121a obtains the frame number determined in the step s 21, the shared key corresponding with determined CID and index from control part 126.Further, encryption unit 121a generates initialization vector according to frame number and index.For the generation method of initialization vector, will describe in detail afterwards.
[step S25] encryption unit 121a is by the block of information of fragment data packets for the bit long corresponding with used cryptographic algorithm.Then, encryption unit 121a uses message blocks, generates the ICV as certification data.Further, encryption unit 121a uses shared key and initialization vector, and to message, fast and ICV is encrypted.In addition, the generation of ICV can also be omitted.Further, also can not be encrypted ICV.
[step S26] PDU generating unit 121 encapsulates the packet of encrypting in step s 25 (pay(useful) load) and ICV, and generates MAC-PDU.Such as, the 121 pairs of pay(useful) loads of PDU generating unit and ICV add MAC head and CRC.
[step S27] control part 126 makes the index delta of the CID determined in step s 24 which (only increasing by 1), and upgrades key management table 125a.Further, the process of step S23 is entered into.
[step S28] sending part 124 by generate in step S26, encoded and the MAC-PDU modulated by modulation portion 123 by coding unit 122, the signal as the DL-Burst being mapped to radio frames sends.
Thus, base station 100, for each packet, according to frame number and the index generation initialization vector of the radio frames used in transmission, and uses initialization vector and distributes in advance to the shared key of travelling carriage 200, being encrypted packet.Owing to using initialization vector according to each packet, therefore, it is possible to the decline of the fail safe suppressing to reuse identical shared key and cause.Further, owing to utilizing frame number in the generation of initialization vector, therefore, it is possible to while easily carrying out generating, used initialization vector is also easily made to reproduce at travelling carriage 200.
Figure 11 is the figure of the 1st example representing initialization vector.Herein, the example that bit long is the initialization vector of 13 bytes (104 bit) is illustrated.In addition, this initialization vector is sometimes also referred to as nonce (Nonce).MAC head containing 5 bytes in initialization vector, the setting (reservation value) of 4 bytes, the frame number of 3 bytes and the index of 1 byte.
MAC head is identical with MAC of being added to MAC-PDU.But in the MAC head being additional to MAC-PDU, the HCS of 1 byte of error detection is excluded.Setting is fixing bit string, to be such as whole bit be zero bit string (being expressed as 0x00000000 with 16 systems).Frame number is the frame number of the radio frames used in the transmission of the packet of encryption.Index is the numbering of the order represented according to the MAC-PDU in each radio frames linking definition.
By in conjunction with above-mentioned 4 kinds of bit strings, generate initialization vector.But, for the order arranging 4 kinds of above-mentioned bit strings, can various distortion be carried out.Further, to above-mentioned bit length, also various distortion can be carried out.
Figure 12 is the figure of the example representing encryption method.Figure 12 represents the object lesson of the encryption performed in above-mentioned steps S25.As mentioned above, in the present embodiment, the situation that encryption mode uses AES-CCM is considered as.That is, use CBC schema creation ICV, and use count mode to be encrypted packet.
First, by fragment data packets be the message blocks M that specified bit is long 1~ M n.Then, shared key K is used, with CBC schema creation certification data.That is, with the message blocks M of AES to front 1be encrypted.Calculate encrypted result and message blocks M 2xOR, and with AES, result of calculation to be encrypted.Same below, repeatedly carry out the encrypted result and the message blocks M that calculate leading portion kxOR and with the process of AES encryption.Finally, the message blocks M at leading portion encrypted result and end is calculated nxOR, and with AES, result of calculation be encrypted and obtain Tag.Tag is the certification data before encryption.
Afterwards, use initialization vector IV and shared key K, offset breath block M with count mode 1~ M nbe encrypted with Tag.That is, be encrypted with the IV+1 that AES obtains IV increment.Calculate encrypted result and front message blocks M 1xOR, obtain cryptographic block C 1.Similarly in the following, with AES, the IV+k obtained by IV successively increment is encrypted, and calculates encrypted result and message blocks M kxOR, obtain cryptographic block C k.To the message blocks M at end nafter being encrypted, finally with AES, IV+ (n+1) being encrypted, and calculating the XOR of encrypted result and Tag, obtain the ICV of encryption.
In conjunction with the cryptographic block C so obtained 1~ C nblock, and become the pay(useful) load of MAC-PDU.In addition, also can not be encrypted Tag and use as ICV.Further, also different shared keys can be used in CBC pattern and count mode.Further, message blocks M 1~ M nencryption can successively carry out, also can walk abreast and carry out its all or part of.Further, also can walk abreast the generation carrying out Tag and message blocks M 1~ M nencryption.
Figure 13 represents that grouping receives the flow chart of process.Herein, consider that travelling carriage 200 receives the situation of MAC-PDU.But the situation that base station 100 carries out receiving is also identical.Below, along number of steps, the process shown in Figure 13 is described.
[step S31] acceptance division 213 receives radio frames.
[step S32] demodulation section 214 carries out demodulation to the DL-Burst be included in the radio frames that receives in step S31, and lsb decoder 215 couples of DL-Burst decode.Control information extraction unit 216 extracts the MAC-PDU on ground for the purpose of our station.
[step S33] control part 226 obtains DL-MAP from control information extraction unit 216, and determines the frame number of the radio frames received in step S31.But control part 226 also can not use the frame number be included in DL-MAP, and counts the frame number of radio frames.
The index of the key management table (table same with key management table 125a) be stored in table storage part 225 is initialized as zero by [step S34] control part 226.
[step S35] divide into groups reproducing unit 217 judge be included in the MAC-PDU of the radio frames received in step S31, whether remain the MAC-PDU do not deciphered.When there is the MAC-PDU do not deciphered, enter into the process of step S36.When the MAC-PDU do not deciphered, terminate to receive process.
[step S36] reproducing unit 217 of dividing into groups determines the CID corresponding with the packet obtained from control information extraction unit 216.Decryption part 217a obtains from control part 226 frame number and the shared key corresponding with determined CID and index determined among step S33.Further, decryption part 217a generates initialization vector according to frame number and index.The generation method of initialization vector is identical with during encryption.
The pay(useful) load of MAC-PDU is divided into the cryptographic block of the bit long corresponding with used cryptographic algorithm by [step S37] decryption part 217a.Further, decryption part 217a is used in the shared key obtained in step S36 and the initialization vector generated, and is decrypted cryptographic block and ICV.
Afterwards, decryption part 217a uses ICV inspection pay(useful) load with or without being tampered.But, the inspection of integrality is not carried out when not adding ICV.In the situation of passed examination or when not checking, obtained packet is outputted to data processing division 218 by grouping reproducing unit 217.
[step S38] control part 226 makes the index delta of the CID determined in step S36 (only increasing by 1), and upgrades key management table.Further, the process of step S35 is entered into.
Thus, travelling carriage 200, to each MAC-PDU on ground for the purpose of self, according to frame number and the index generation initialization vector of radio frames, and uses initialization vector and in advance from the shared key of base station 100 acquisition, is decrypted MAC-PDU.Owing to utilizing frame number in the generation of initialization vector, therefore, it is possible to while easily reproducing the initialization vector of base station 100 use, inhibit the amount of information being added to MAC-PDU.
In addition, when each MAC-PDU is attached with index, the MAC-PDU counting number that control part 226 can not be deciphered control part 226.Now, decryption part 217a can use the index being attached to each MAC-PDU, generates initialization vector.
Figure 14 is the figure of the example representing decryption method.Figure 14 represents the object lesson of the deciphering performed in above-mentioned steps S37.As mentioned above, in the present embodiment, the situation that encryption mode uses AES-CCM is considered as.That is, use count mode to be decrypted MAC-PDU, and use the integrality of CBC pattern examination decrypted result.
First, the pay(useful) load of MAC-PDU is divided into the cryptographic block C that specified bit is long 1~ C n.Then, initialization vector IV and shared key K is used, with count mode to cryptographic block C 1~ C nbe decrypted with ICV.That is, be encrypted with the IV+1 that AES obtains IV increment.Calculate the cryptographic block C of encrypted result and front 1xOR, obtain message blocks M 1.Similarly in the following, with AES to IV successively increment and the IV+k obtained be encrypted, and calculate encrypted result and cryptographic block C kxOR, obtain message blocks M k.At the cryptographic block C to end nafter being decrypted, with AES, IV+ (n+1) being encrypted, and calculating the XOR of encrypted result and ICV and obtain Tag#1.
Afterwards, the message blocks M obtained according to deciphering 1~ M n, with CBC schema creation inspection data.That is, with the message blocks M of AES to front 1be encrypted.Calculate encrypted result and message blocks M 2xOR, and with AES, result of calculation to be encrypted.Similarly in the following, the encrypted result and the message blocks M that calculate leading portion is repeated kxOR and the process of encrypting with AES.Finally, the encrypted result of leading portion and the message blocks M at end is calculated nxOR, and with AES, result of calculation be encrypted and obtain Tag#2.
If Tag#1 with Tag#2 is consistent, then confirm as message blocks M 1~ M nbe not tampered.Further, obtained message blocks M is combined 1~ M nblock, become the content of packet.In addition, when ICV does not have encrypted, ICV and Tag#2 is compared.Further, also different shared keys can be used in CBC pattern and count mode.Further, cryptographic block C 1~ C ndeciphering, successively can carry out, also can walk abreast and carry out its all or part of.
Figure 15 is the 1st flow chart representing key updating process.Herein, consider that travelling carriage 200 asks to change the situation of shared key to base station 100.This process repeats in travelling carriage 200.Below, along number of steps, the process shown in Figure 15 is described.
[step S41] control part 226 determines whether to obtain the shared key relevant with the link of current setting from base station 100.As the situation not having shared key, such as, can consider that the situation of base station 100 accessed again by travelling carriage 200.When there is shared key, enter into step S42.When there is no shared key, enter into the process of step S44.
The valid period that [step S42] control part 226 notifies from base station 100 when comparing the elapsed time from obtaining shared key and obtain, and judge whether near the phase (such as, remaining time whether not enough stipulated time).When there being the sufficient time to expiring, enter into the process of step S43.In the situation of being down to the wire, enter into the process of step S44.
[step S43] control part 226 compare obtain shared key time frame number and current frame number, and judge to number whether fast steamer complete once (such as, the whether not enough stated number of remaining radio frames to frame number has been taken turns once) from acquisition shared key start frame.When having the sufficient time when having taken turns once to frame number, end process.When frame number fast steamer complete once, enter into the process of step S44.
[step S44] control part 226 generates the control information (such as, PKM-REQ) that shared key is changed in request, and outputs to PDU generating unit 221.This control information is included in radio frames and is sent to base station 100.
[step S45] control part 226 obtains the frame number of the control information (such as, PKM-RSP) comprising shared key and valid period and the radio frames containing this control information from control information extraction unit 216.Further, control part 226, while obtained shared key being registered in the key management table being stored in table storage part 225, keeps valid period of obtaining and frame number.
Thus, travelling carriage 200, when being connected with base station 100, obtains from base station 100 shared key used the encryption and deciphering of packet.Afterwards, before the valid period through being specified by base station 100, asking to base station 100 and changing shared key.Further, even if before the valid period, also before frame number has been taken turns once, ask to base station 100 and change shared key.Thereby, it is possible to prevent the group using (at least within the sufficiently long time) identical shared key and initialization vector in the encryption of multiple packet.In addition, base station 100 also can be made to manage the renewal timing of shared key.
By using such mobile communication system, according to shared key and initialization vector, respectively packet can be encrypted.Therefore, even if identical shared key to be used for the encryption of multiple packet, the decline of fail safe can also be suppressed.
Now, in the generation of initialization vector, make use of transmit packet the frame number of radio frames and radio frames in the storage order of packet.Therefore, it is possible to from the information being attached to each packet, cut down the information being used for reproducing initialization vector at receiver side, can the traffic be suppressed.Further, by making the renewal of shared key timing and frame number take turns timing interlock once, can prevent from the encryption of multiple packet, use identical shared key and the group of initialization vector, can fail safe be improved.
Then, the 2nd execution mode is described in detail with reference to accompanying drawing.By with the difference of the 1st above-mentioned execution mode centered by be described, and to omit about the explanation of identical item.In the mobile communication system of the 2nd execution mode, more easily can upgrade shared key with the cycle different from the cycle period of frame number.The mobile communication system of the 2nd execution mode, same with the mobile communication system of the 1st execution mode shown in Fig. 2, can realize with base station and travelling carriage.This base station and travelling carriage can realize by the modular structure identical with the block diagram shown in Fig. 3, Fig. 4.Below, symbol description 2nd execution mode identical with Fig. 3, Fig. 4 is used.
Figure 16 is the figure of the 2nd structure example representing key management table.Key management table 125b is stored in the table storage part 125 of base station 100.Also the table identical with key management table 125b is stored in the table storage part 225 of travelling carriage 200.The project representing CID, shared key, index and spreading parameter is provided with in key management table 125b.Associating each other in transversely arranged information of projects.
Represent that the meaning of project of CID, shared key and index is identical with the key management table 125a of the 1st execution mode shown in Fig. 5.In the project representing spreading parameter, being benchmark with the bit long of frame number (such as, 24 bits), being set with the value representing expansion or degeneracy scope when utilizing as initialization vector.
" 0 " means that the bit string of expression frame number is all included in initialization vector.The situation that negative value means degeneracy frame number to use, namely cuts down the situation of removing a part of bit.Such as, when "-2 ", sequence 2 high bits using in the generation of initialization vector of pruning.Now, can consider to make the update cycle of shared key become 1/4th of the cycle period of frame number.The situation that positive value means expansion frame number and uses, namely to the situation of frame number additional extension bit.In extended bit, the value of increment when each frame number has taken turns a time can be used in.Such as, when " 4 ", add 4 bits in sequence eminence and use in generation at initialization vector.Now, the update cycle of shared key also can be made to become 16 times of the cycle period of frame number.
In addition, when spreading parameter is positive, the value of current extended bit is also registered in key management table 125b.Such as, when distributing shared key in base station 100 to travelling carriage 200, extended bit is initialized as zero.Afterwards, each frame number from distributing to when having taken turns one time, make extended bit increment.Current extended bit can be managed respectively by base station 100 and travelling carriage 200, also can be managed by a square tube and regularly or aperiodically notify to the opposing party.
As mentioned above, by representing that the bit string of frame number is expanded or degeneracy utilizes, the update cycle of shared key can be set more neatly.Spreading parameter can notify as control information.Such as, can consider to be included in the PKM-RSP shown in Fig. 9 from base station 100 to the situation that travelling carriage 200 notifies.Spreading parameter such as can show with the signed integer of 4 bits.
Figure 17 is the figure of the 2nd example representing initialization vector.Herein, the example that bit long is the initialization vector of 13 bytes (104 bit) is shown.In this initialization vector, include the index of the MAC head of 5 bytes, the setting (reservation value) of 3 bytes, the repeat number of 1 byte, the frame number of 3 bytes and 1 byte.
The meaning of MAC head, setting and index is identical with the initialization vector of the 1st execution mode shown in Figure 11.Repeat number is the bit string comprising above-mentioned extended bit.In this example embodiment, 8 bits can be set as by maximum for extended bit.When extended bit is less than 8 bit, all the other bits of repeat number become zero.Frame number in a same manner as in the first embodiment, is the frame number of the radio frames used in the transmission of the packet of encryption.But, when using when carrying out degeneracy to frame number, make the high bit of the sequence of number corresponding to degeneracy amount become zero.
Such as, when spreading parameter is set as " 0 ", make the bit of repeat number all become zero, and the bit of expression frame number is all covered in initialization vector.When spreading parameter is set as "-2 ", make the bit of repeat number all become zero, and make the sequence of the bit string of expression frame number high 2 bit permutation be zero to cover in initialization vector.When spreading parameter is set as " 4 ", make the sequence of repeat number high 4 bits become zero, 4 bits making sequence low become the bit corresponding with the cycle-index of frame number, and the bit of expression frame number is all covered in initialization vector.
By the bit string in conjunction with above-mentioned 5 kinds, generate initialization vector.But, for the order of the bit string of above-mentioned 5 kinds of arrangement, can various distortion be carried out.Further, for the length of above-mentioned bit, also various distortion can be carried out.
But, in mobile communication system, also there is frame number nonsynchronous system between adjoining base station.Now, when continuing afterwards before the handover to use identical shared key, the group of certain shared key and the frame number occurred before the handover can be produced, the danger again occurred after the handover.Therefore, from the viewpoint of fail safe, preferably change used shared key when switching.
But, when using when expanding frame number, also can not lose the change of omitting shared key when switching safely.That is, when switching, travelling carriage 200 changes the extended bit (such as, making extended bit increment) being added to frame number.By changing extended bit, even if frame number is identical, also different initialization vectors can be generated.Therefore, it is possible to prevent from using identical shared key and the group of initialization vector in the encryption of multiple packet.
Figure 18 is the sequential chart of the flow process representing switching controls.Herein, consider that travelling carriage 200 carries out the situation from base station 100 to the switching of base station 100a.Below, along number of steps, the process shown in Figure 18 is described.
The radio frames comprising the MAC-PDU encrypted is received and dispatched in [step S51] travelling carriage 200 and base station 100.In this condition, when travelling carriage 200 has carried out the low grade of received power from base station 100 and will switch the judgement of connection destination base station, the control information (MSHO-REQ) that request switches is sent to base station 100.Current link information, the information of communication capacity of travelling carriage 200, the information etc. of the Search Results of peripheral base station can be comprised in MSHO-REQ.Travelling carriage 200 such as sends MSHO-REQ with the UL-Burst of radio frames.
[step S52] base station 100, according to the information being included in the MSHO-REQ received from travelling carriage 200, generates control information (HO-REQ), and is sent to the base station 100a of mobile destination candidate.In addition, multiple mobile destination candidate can also be there is.
[step S53], as the response to the HO-REQ received from base station 100, control information (HO-RSP) is sent to base station 100 by base station 100a.The information can received travelling carriage 200, Qos can be ensured, the expression condition of contacts such as high speed switching controls can be carried out can be included in HO-RSP.
[step S54] base station 100, according to the HO-RSP received from base station 100a, generates control information (BSHO-RSP), and is sent to travelling carriage 200.Can comprise in BSHO-RSP and guaranteed qos etc. can represent the information of condition of contact.Base station 100 such as sends BSHO-RSP with the DL-Burst of radio frames.
[step S55] base station 100 will represent that the control information (HO-ACK) confirming to receive HO-RSP is sent to base station 100a.In addition, can with the at random message of order forwarding step S54 and the message of step S55.
[step S56] travelling carriage 200 is according to the BSHO-RSP received from base station 100, determine mobile destination base station (herein, determine as base station 100a), and will represent that the control information (HO-IND) of mobile destination base station is sent to base station 100.Base station 200 such as sends HO-IND with the UL-Burst of radio frames.
[step S57] base station 100, to the mobile destination base station of being specified by the HO-IND received from travelling carriage 200 (base station 100a), sends the control information (HO-CNF) of notice travelling carriage 200 movement.In HO-CNF, shared key and extended bit that base station 100 uses when communicating with travelling carriage 200 can be comprised.In addition, extended bit is incremented before the handover afterwards.The increment of extended bit, can be undertaken by the base station 100 of moving source, also can be undertaken by the base station 100a of mobile destination.
Distance measurement request (RNG-REQ), in order to start to carry out the communication with base station 100a, is sent to base station 100a by [step S58] travelling carriage 200.Travelling carriage 200 such as utilizes the ranging region of radio frames to send RNG-REQ.
Range finding response (RNG-RSP), for the RNG-REQ received from travelling carriage 200, is sent to travelling carriage 200 by [step S59] base station 100a.In RNG-RSP, the CID used in the communication between base station 100a and travelling carriage 200 and/or the mark representing the change with or without shared key can be included in.Base station 100a such as sends RNG-RSP with the DL-Burst of radio frames.
Travelling carriage 200, when being indicated change shared key by RNG-RSP, carries out the process for obtaining shared key.On the other hand, when indicated by RNG-RSP do not change shared key, make with the extended bit increment that uses in the communication of base station 100.In addition, for the renewal of extended bit, as long as carried out before encrypting/decrypting data grouping.
Thus, base station 100a and travelling carriage 200, by changing extended bit (such as, increment), can continue to use the shared key before switching.Such as via upper station, extended bit can be notified from the base station 100 before movement to the base station 100a after movement.But, also can by travelling carriage 200 to the extended bit of 100a notice in base station before changing or after changing after movement.
According to mobile communication system as above, the effect identical with the 1st execution mode can be obtained.And then, by using the mobile communication system of the 2nd execution mode, can easily with the cycle different from the cycle period of frame number, the change cycle of setting shared key.In addition, by using extended bit, can not damage and continue after the handover safely to use and switch front identical shared key.Thus, while alleviating the processing load changing shared key, promptly can restart communication after the handover.
Then, the 3rd execution mode is described in detail with reference to accompanying drawing.By with the difference of the 1st above-mentioned execution mode centered by be described, and to omit about the explanation of identical item.In the mobile communication system of the 3rd execution mode, the renewal of shared key timing is made also to depend on the quantity of encrypted packet.The mobile communication system of the 3rd execution mode, same with the mobile communication system of the 1st execution mode shown in Fig. 2, can realize with base station and travelling carriage.This base station and travelling carriage can realize by the modular structure identical with the block diagram shown in Fig. 3, Fig. 4.Below, symbol description 3rd execution mode identical with Fig. 3, Fig. 4 is used.
Figure 19 is the figure of the 3rd structure example representing key management table.Key management table 125c is stored in the table storage part 125 of base station 100.Also the table identical with key management table 125c is stored in the table storage part 225 of travelling carriage 200.The project representing CID, shared key, index and PDU quantity is provided with in key management table 125c.Projects associate each other in transversely arranged information.
Represent that the meaning of project of CID, shared key and index is identical with the key management table 125a of the 1st execution mode shown in Fig. 5.In the project representing PDU quantity, be set with the quantity of the MAC-PDU employing shared key.PDU quantity is initialized to zero when obtaining shared key, and is incremented when each use shared key is encrypted or deciphers.
Herein, when certain link sends at short notice and have received a large amount of MAC-PDU, even if before frame number has been taken turns once, also preferably shared key can have been changed as early as possible from the viewpoint of fail safe.Thereby, it is possible to expect presetting the maximum PDU number as the upper limit of identical shared key can be used continuously.Maximum PDU number can notify as control information from base station 100 to travelling carriage 200.Such as, can expect being included in the PKM-RSP shown in Fig. 9, and inform travelling carriage 200 from base station 100.Maximum PDU numerical example is if show with the integer type of 4 bytes (32 bit).
Figure 20 is the 2nd flow chart representing key updating process.Herein, consider that the situation of the change of shared key asked by travelling carriage 200 to base station 100.This process repeatedly performs in travelling carriage 200.Below, along number of steps, the process shown in Figure 20 is described.
[step S61] control part 226 judges whether the shared key obtaining the link about current setting from base station 100.When there is shared key, enter into the process of step S62.When there is no shared key, enter into the process of step S65.
By the valid period notified from base station 100 when [step S62] control part compares the elapsed time from obtaining shared key and obtains, and judge whether near the phase.When there being enough time to expiring, enter into the process of step S63.In the situation of being down to the wire, enter into the process of step S65.
[step S63] control part 226 compares frame number when obtaining shared key and current frame number, judgment frame numbering whether from obtaining shared key fast steamer once complete.When having enough time when having taken turns once to frame number, enter into the process of step S64.When frame number fast steamer complete once, enter into the process of step S65.
[step S64] control part 226 compares the PDU number that the current shared key of use has carried out encrypting or deciphering and the maximum PDU number notified from base station 100, and judge whether to arrive maximum PDU number (such as, whether the difference of maximum PDU number and current PDU number is less than stated number) soon.When still having more than needed to maximum PDU number, end process.When close to maximum PDU number, enter into the process of step S65.
[step S65] control part 226 generates the control information (such as, PKM-REQ) that shared key is changed in request, and outputs to PDU generating unit 221.This control information is included in radio frames and is sent to base station 100.
[step S66] control part 226 from control information extraction unit 216 obtain comprise shared key, valid period and maximum PDU number control information (such as, PKM-RSP) and comprise the frame number of radio frames of this control information.Further, control part 226 makes PDU number reset while obtained shared key being registered in the key management table being stored in table storage part 225.Further, valid period of obtaining and frame number is kept.
Thus, even if travelling carriage 200 before frame number has been taken turns once, also before the access times of shared key reach the upper limit, can be asked to base station 100 and changing shared key before valid period of being specified by base station 100.Thereby, it is possible to prevent the decline of the fail safe when the short time sends and receive a large amount of MAC-PDU.In addition, the renewal timing of shared key also can be managed by base station 100.
According to mobile communication system as above, the effect identical with above-mentioned 1st execution mode can be obtained.And then, by using the mobile communication system of the 3rd execution mode, the renewal of shared key timing can be made also to depend on the access times of shared key.Therefore, it is possible to improve the fail safe of coded communication further.In addition, the execution mode being combined with the 2nd execution mode and the 3rd execution mode can be considered.
Foregoing illustrate only principle of the present invention.And then, those skilled in the art can carry out various deformation, change, the present invention be not limited to above-mentioned shown in, the structure accurately that illustrates and application examples, corresponding whole variation and equivalent, be included in the scope of the present invention based on additional claim and equivalent thereof.
1: dispensing device 1a: encryption unit
1b: sending part 2: receiving system
2a: acceptance division 2b decryption part
3: frame 3a, 3b: packet
3c: frame number
1. a dispensing device, it sends the frame comprising more than one packet, and it is characterized in that, described dispensing device has:
Encryption unit, it generates initialization vector according to the frame number of described frame used in the transmission of described packet, and according to the encryption key of generated described initialization vector and regulation, is encrypted respectively to described packet; And
Sending part, it sends the described frame comprising the described packet after being encrypted by described encryption unit,
In the generation of described initialization vector, the bit string after using degeneracy can be selected as a part for initialization vector or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number
The quantity of the bit that described sequence is high and the bit number of described counting can be specified by parameter,
In the described cycle period of the bit string of described encryption unit after each described degeneracy or the bit string after described expansion, change described encryption key.
2. dispensing device according to claim 1, is characterized in that,
Described sending part will represent that the indexing of the position of described packet sends to described packet.
3. dispensing device according to claim 1, is characterized in that,
Described encryption unit, before the quantity of the described packet using described encryption key to be encrypted reaches stated number, changes described encryption key.
4. a receiving system, is characterized in that, described receiving system has:
Acceptance division, its receiving package is containing the frame of more than one encrypted packet; And
Decryption part, it generates initialization vector according to the frame number of described frame received by described acceptance division, and according to the decruption key of generated described initialization vector and regulation, is decrypted respectively to the described packet be included in described frame,
In the described cycle period of the bit string of described decryption part after each described degeneracy or the bit string after described expansion, change described decruption key.
5. receiving system according to claim 4, is characterized in that,
The index representing the position of described packet in described frame is attached with in described packet,
Described decryption part uses the described index being added to described packet, generates described initialization vector.
6. receiving system according to claim 4, is characterized in that,
Described decryption part, before the quantity of the described packet using described decruption key to be decrypted reaches stated number, changes described decruption key.
7. a sending method for dispensing device, send the frame comprising more than one packet, it is characterized in that, described sending method comprises:
Generate initialization vector according to the frame number of the described frame used in the transmission of described packet, and according to the encryption key of generated described initialization vector and regulation, respectively described packet is encrypted; And
Send the described frame comprising encrypted described packet,
Be changed in the described cycle period of the bit string of described encryption key after each described degeneracy or the bit string after described expansion.
8. a method of reseptance for receiving system, is characterized in that, described method of reseptance comprises:
Receiving package is containing the frame of more than one encrypted packet;
Generate initialization vector according to the frame number of received described frame, and according to the decruption key of generated described initialization vector and regulation, respectively the described packet be included in described frame be decrypted,
Be changed in the described cycle period of the bit string of described decruption key after each described degeneracy or the bit string after described expansion.
9. a communication means, the method is the communication means of mobile communication system, and this mobile communication system has the 1st base station and the 2nd base station that the frame comprising more than one packet are sent to travelling carriage, and it is characterized in that, this communication means comprises:
Described 1st base station generates the 1st initialization vector of the 1st value comprising value and the regulation generated according to the frame number of the described frame defined by described 1st base station, and encryption key according to the rules and described 1st initialization vector that generates, described packet is encrypted, and sends the described frame comprising encrypted described packet;
The communication object of described travelling carriage is switched to described 2nd base station from described 1st base station;
Described 2nd base station generates the 2nd initialization vector of the 2nd value comprising value and the regulation different from described 1st value generated according to the frame number of the described frame defined by described 2nd base station, and according to the encryption key of described regulation and described 2nd initialization vector that generates, described packet is encrypted, and send the described frame comprising encrypted described packet
In the generation of described 1st initialization vector and described 2nd initialization vector, the bit string after using degeneracy can be selected as a part for initialization vector or using the part of the bit string after expansion as initialization vector, wherein, this degeneracy is by being 0 to obtain bit permutation high for the sequence of specified quantity in the bit string of described frame number, this expansion obtains by the bit string counted to get with the cycle period of specified bit number to described frame number is added to described frame number
10. a communication means, the method is the communication means of travelling carriage, and the frame comprising more than one packet is sent to the 1st base station or the 2nd base station by this travelling carriage, it is characterized in that,
Generate the 1st initialization vector of the 1st value comprising value and the regulation generated according to the frame number of the described frame defined by described 1st base station, and encryption key according to the rules and described 1st initialization vector that generates, described packet is encrypted, and the described frame comprising encrypted described packet is sent to described 1st base station
Communication object is switched to described 2nd base station from described 1st base station,
Generate the 2nd initialization vector of the 2nd value comprising value and the regulation different from described 1st value generated according to the frame number of the described frame defined by described 2nd base station, and according to the encryption key of generated described 2nd initialization vector and described regulation, described packet is encrypted, and the described frame comprising encrypted described packet is sent to described 2nd base station
CN200880130952.8A 2008-09-04 2008-09-04 Transmitting device, receiving device, transmitting method and receiving method CN102144370B (en)
PCT/JP2008/065977 WO2010026637A1 (en) 2008-09-04 2008-09-04 Transmitting device, receiving device, transmitting method and receiving method
CN102144370A CN102144370A (en) 2011-08-03
CN102144370B true CN102144370B (en) 2015-04-15
ID=41796825
CN200880130952.8A CN102144370B (en) 2008-09-04 2008-09-04 Transmitting device, receiving device, transmitting method and receiving method
US (1) US8538021B2 (en)
JP (1) JP5338816B2 (en)
CN (1) CN102144370B (en)
WO (1) WO2010026637A1 (en)
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2008-09-04 JP JP2010527622A patent/JP5338816B2/en not_active Expired - Fee Related
2008-09-04 CN CN200880130952.8A patent/CN102144370B/en not_active IP Right Cessation
2008-09-04 WO PCT/JP2008/065977 patent/WO2010026637A1/en active Application Filing
2011-02-11 US US13/025,551 patent/US8538021B2/en active Active
WO2010026637A1 (en) 2010-03-11
US8538021B2 (en) 2013-09-17
CN102144370A (en) 2011-08-03
JP5338816B2 (en) 2013-11-13
JPWO2010026637A1 (en) 2012-01-26
US20110138173A1 (en) 2011-06-09
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US9071416B2 (en) 2015-06-30 Galois/counter mode encryption in a wireless network
EP1739903B1 (en) 2012-10-31 Authentication system and method thereof in a communication system
Termination date: 20180904