Patent Application
20050169267
This application claims the priority of Korean Patent Application No. 2004-6610, filed on Feb. 2, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a Mobile lpv6 (Internet Protocol version 6) packet, and more particularly to a method and apparatus for securing a Mobile lpv6 packet.
2. Description of Related Art
The mobile node 11 refers to a node that can change a point of attachment from one link to another. The home agent 12 refers to a router in which the mobile node 11, which has moved from a home link (link A), registers its current care of address (COA). The home agent 12 exists at the home link (link A) of the mobile node 11. The COA is an address used at link B where the mobile node is currently at. The corresponding node 13 refers to a node, communicating with the mobile node 11.
As shown in
Referring to
As described above, during the unregistered COA usage period the mobile node 11 uses the unregistered COA to communicate with the corresponding node 13. However, since the corresponding node 13 does not recognize a COA which is not registered at the home agent 12 as the new address of the mobile node 11, the corresponding node 13 recognizes the home address 3FFE:2E01:2A:201::1 , which is the address of the mobile node 11 when the communication started with the corresponding node 13, as the address of the mobile node 11. This situation includes cases in which the mobile node 11 moves from a home link to an external link and cases in which the mobile node 11 moves to another external link from the external link. In the latter, with respect to the above example, the home address is the COA of the external link, where the mobile node 11 has was at. If a secured channel is configured between the home address 3FFE:2E01:2A:201::1 of the mobile node and the address 3FFE:2E01:2A:100::1 of the corresponding node, the two communicate through a secured channel. However, the secured channel is not yet configured between the unregistered COA 3FFE:2E01:2A:301::1, and the address 3FFE:2E01:2A:100::1 of the corresponding node 13. Therefore, the corresponding node 13 which received a packet that has an unregistered COA as a destination address cannot trust the received packet and discards the packet. Since the packet that is discarded by the corresponding node 13 is transmitted though an unsecured channel, the packet can be accessed by unauthorized persons or even lost.
In addition, in a connection-oriented communication like a transmission control protocol (TCP), abandoned packets are retransmitted. In a connection-less communication such as a user datagram protocol (UDP), abandoned packets are not retransmitted but are ignored. Both cases have the problem of network overload. In other words, in the case of the TCP, the network is overloaded by retransmission, and in the case of the UDP, the network is overloaded due to the ignored packet, that is, due to the transmission of meaningless packets.
Furthermore, when reception of a binding update and/or binding acknowledgement is delayed because a problem occurs in the home agent 12 or the network, the unregistered COA usage period is extended and the problems mentioned above aggravate.
An aspect of the present invention provides a device and method for preventing a mobile packet from being accessed by an unauthorized person or lost during transmission.
According to an aspect of the present invention, there is provided a method of securing packets, including: confirming, by a mobile node in an external link, whether an address of the mobile node is registered at a home agent at which a home link of the mobile node is present; and discarding a packet that should be transmitted when it is confirmed that the address is registered.
According to another aspect of the present invention, there is provided a device for securing packets, including: a home registration confirmer confirming whether a mobile node that is at an external link registers an address of the mobile node at a home agent at which a home link of the mobile node is present; and a packet discarder discarding the packet that should be transferred when the address is confirmed to be registered.
According to another aspect of the present invention, there is provided a method of securing packets to be received, including: receiving a packet; confirming whether a care of address (COA) is registered at a home agent; confirming whether a received packet is a binding acknowledgement; configuring the COA as not registered when registration of the COA at the home agent and that the receiving packet is a binding acknowledgement are confirmed; and processing the received packet when the COA is configured as not registered, the received packet is confirmed not to be a binding acknowledgement, or when the COA is confirmed not to be registered.
According to still other aspects of the present invention, there are provided computer readable recording media having recorded thereon a program for executing the aforesaid methods.
Additional and/or other aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
Referring to
As shown in
When transmitting a packet which has the COA 3FFE:2E01:2A:301::1 as a source address in which the mobile node 31 is not registered at during an unregistered COA usage period as shown in
Referring to
The packet receiver 311 receives a packet from a lower layer positioned at a lower portion of an IP layer, for example, a link layer. The packet is received from the corresponding node 33 via link C, the Internet, and link B (the packet goes through routers placed along a transmission path). The transmission request receiver 312 receives a request to transmit the packet from an upper layer which is placed in an upper portion of the IP layer, for example, a TCP layer or from an inside of IP layer.
The packet confirmer 313 confirms whether the received packet is a binding update so as to confirm whether a current point falls within the unregistered COA usage period when the mobile node 31 receives the packet, that is, when the packet receiver 311 receives the packet as shown in
In addition, the packet confirmer 313 confirms whether a destination of the packet, which should be transmitted, is within the external link (link B) at which the mobile node 31 is currently present, and confirms whether the packet that should be transmitted is a binding acknowledgement to confirm whether it is alright for the packet that should be transmitted to be transmitted to the outside when the mobile node 31 transmits a packet, that is, when the transmission request receiver 312 receives a request to transmit a packet. When the destination of the packet that should be transmitted is within the external link (link B) at which the mobile node 31 is currently present, since there is not a possibility that it will be exposed to unspecified persons on the Internet, it is alright to transmit the packet without taking any specific measures. An example of such a packet is neighbor discovery, neighbor solicitation, neighbor advertisement, router solicitation, and router advertisement etc. are types of neighbor discovery. In addition, since such a packet contains information essential to perform operations within a link, transmission should not be blocked. Furthermore, when the packet that should be transmitted is a binding update, it is alright if the information, which is included in the binding update, is accessed or lost and this information is essential for registering COA 3FFE:2E01:2A:301::1 at the home agent 32 or updating another COA and should not be blocked. Especially, the packet confirmer 313 confirms the packet that should be transmitted as a binding update and it confirms whether the packet is an initial binding update to confirm whether the current point of the binding update falls within the unregistered COA usage period shown in
The home registration configuration unit 314 configures the COA 3FFE:2E01:2A:301::1 as not being registered by the home agent 32 when it is confirmed that COA 3FFE:2E01:2A:301::1 is not registered at the home registration confirmer 315, and the received packet is confirmed to be a binding acknowledgement by the packet confirmer 313.
The home registration configuration unit 314 configures the COA 3FFE:2E01:2A:301::1 as being registered at the home agent 32 when the packet confirmer 313 confirms that the packet, which should be transmitted, is an initial binding acknowledgement. According to the present embodiment, the home registration configuration unit 314 can configure the COA 3FFE:2E01:2A:301::1 as not being registered by recording a value that indicates that COA 3FFE:2E01:2A:301::1 is not being registered at the home registration flag, for example 0, and can configure COA 3FFE:2E01:2A:301::1 as being registered by recording a value that indicates COA 3FFE:2E01:2A:301::1 is being registered at the home registration flag, for example, 1.
The home registration confirmer 315 confirms whether COA 3FFE:2E01:2A:301::1 is registered at the home agent 32 when the packet is received at the packet receiver 311 or it is confirmed that the destination of the packet that should be transmitted by the packet confirmer 313 is not present within the external link (link B) and when it is confirmed that the packet that should be transmitted is not a binding update. The home registration confirmer 315 makes a confirmation on the basis of the configuration of the home registration configuration unit 314. In other words, the confirmation is made considering the home registration flag in which the value indicating whether COA 3FFE:2E01:2A:301::1 is registered is recorded.
The packet processor 316 transmits the obtained data to the upper layer by processing the received packet according to the IP or transmits the packet that should be transmitted to the lower layer form of an IP packet by processing it according to the IP. When it is confirmed by the packet confirmation unit 313 that a destination of the packet that should be transmitted is not present within the external link (link B), the packet is confirmed to be a binding update or the COA 3FFE:2E01:2A:301::1 is confirmed as not being registered at the home registration confirmation unit 315, and the pack processing unit 316 can relay the packet to a lower layer.
The packet discarder 317 discards the packet that should be transmitted when it is confirmed by the packet confirmer 313 of the packet that should be transmitted that the destination of the packet is not present within the external link (link B) or the packet is confirmed to be a binding update or when it is confirmed that COA 3FFE:2E01:2A:301::1 is not registered at the home registration confirmer 315.
First, the packet receiver 311 receives a packet at operation 41. Next, the home registration confirmer 315 confirms whether a COA is registered at the home agent 32. In other words, the home registration confirmer 315 confirms whether the value recorded at the home registration flag is 0. At the same time, the packet confirmer 313 confirms whether the received packet is a binding acknowledgement at operation 42. Next, if the value recorded at the home registration flag is confirmed to be 1 by the home registration confirmer 315 and the received packet is confirmed to be a binding acknowledgement by the packet confirmer 313, the home registration configuration unit 314 configures the COA as not registered at operation 43. In other words, the home registration configuration unit 314 records 0 at the home registration flag. Next, the packet processor 316 processes the received packet when the value recorded at the home registration flag by the home registration confirmer 315 is 0 or it is confirmed that the received packet is not a binding acknowledgement by the packet confirmer 313 or when 0 is recorded at the home registration flag by the home registration confirmer 314.
First, the transmission request receiver 312 receives a request to transmit a packet at operation 51. Next, the packet confirmer 313 confirms whether a destination of the packet that should be transmitted is within the external link (link B) at operation 52. Next, if it is confirmed by the packet confirmer 313 that the destination of the packet is not present within the external link (link B) the packet confirmer 313 confirms whether the packet that should be transmitted is a binding update at operation 53. Next, if it is confirmed that the packet that should be transmitted is a binding update the packet confirmer 313 confirms whether the binding update is an initial binding update at operation 54. Next, if it is confirmed by the packet processor 314 that the binding update is an initial binding update, COA is configured as registered at the home registration configuration unit 314 at operation 55. In other words, the value 1 is recorded at the home registration flag.
Next, if it is confirmed that the packet that should be transmitted is not a binding update, the home registration confirmer 314 confirms whether the COA is registered at the home agent 32 at operation 56. In other words, the home registration confirmer 314 confirms whether the value recorded at the home registration flag is 1. Next, the packet processor 316 processes the packet that should be transmitted when it is confirmed that the destination of the packet that should be transmitted is within the external link (link B) or it is confirmed by the packet confirmer 313 that the binding update is not an initial binding update or the COA is configured to be registered by the home registration configuration unit 314 at operation 57. In addition, when it is confirmed by the home registration confirmer 314 that the COA is not registered, that is, when the value recorded at the home registration flag is 0, the packet processor 316 processes a packet that should be transmitted.
When it is confirmed by the home registration confirmer 314 that the COA is registered, the packet discarder 317 discards a packet that should be transmitted at operation 58.
The above-described embodiments of the present invention can be realized as a code on a recording medium readable by a computer. The recording medium, which a computer can read includes all kinds of recording devices which store data that can be read by a computer system. ROM, RAM, CD-ROMs, magnetic tapes, hard disks, floppy disks, flash memory, and optical data storing devices are examples of the recording medium. The recording medium can also be in a carrier wave form (for example, transmission through the Internet). Furthermore, the recording medium can be accessed from a computer in a computer network, and the code can be stored and executed in a remote method.
According to the above-described embodiments of the present invention, by blocking the transmission of a packet that has an unregistered COA as a source address the exposure or loss of a packet to unspecified persons through an unsecured channel can be prevented. In other words, the above-described embodiments of the present invention can guarantee the security of a packet during the registration of the COA at a home agent. Furthermore, the above-described embodiments of the present invention can reduce network overload by reducing the retransmission of a packet in a connection-oriented communication such as TCP and by not transmitting a packet that would be ignored in a connectionless communication such as UDP.
Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-6610 | Feb 2004 | KR | national |
