# US 2013/0156191 A1 · Communication security method and apparatus of first node and second node communicating based on full duplex communication scheme using near field > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156191 A1 - Document ID: US20130156191A1 - Status: Published application - Kind: A1 - Application number: 13/464,201 - Filed: 2012-05-04 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Jong Bu Lim; Ui Kun Kwon; Sang Joon Kim - Web page: https://patentgrep.com/patent/US20130156191A1 ## CPC - H04L 63/0492: {by using a location-limited connection, e.g. near-field communication or limited proximity of entities} - G06K 19/0723: {the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs} - H04B 5/48: Transceivers - H04B 5/24: Inductive coupling - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - H04B: TRANSMISSION ## Abstract A communication security method and apparatus of a first node and a second node are provided. The first node and the second node communicate with each other based on a full duplex communication scheme using a near field. In the communication security method and apparatus, information to be transmitted may be encrypted based on received information and the encrypted information may be transmitted, in a TX node and an RX node. The communication security method and apparatus prevent an additional node from decrypting the information, and ensure transmission and reception of reliable data. In addition, the communication security method and apparatus prevent information from being decrypted in a physical layer, by periodically or aperiodically exchanging a new encryption key. ## Claims ### Claim 1 A communication security method of a first node, the communication security method comprising: receiving first information from a second node at a previous time, the previous time being recognized by the first node and the second node; encrypting second information using the first information and information on the previous time; and transmitting the encrypted second information to the second node at a next time. ### Claim 2 (depends on 1) The communication security method of claim 1, wherein the encrypting comprises encoding the second information based on the first information. ### Claim 3 (depends on 1) The communication security method of claim 1, wherein the previous time is repeated periodically or aperiodically. ### Claim 4 (depends on 1) The communication security method of claim 1, wherein a near field comprises the first node and the second node that communicate with each other based on a full duplex communication scheme. ### Claim 5 (depends on 4) The communication security method of claim 4, further comprising: determining whether a third node exists within the near field, wherein the third node is distinguished from the second node. ### Claim 6 (depends on 5) The communication security method of claim 5, wherein the determining comprises determining whether the third node exists based on a change in energy in the near field. ### Claim 7 (depends on 5) The communication security method of claim 5, further comprising: interrupting transmission and reception of data between the first node and the second node, when the third node is determined to exist. ### Claim 8 (depends on 1) The communication security method of claim 1, further comprising: transmitting an indicator indicating the previous time, wherein the information on the previous time comprises the indicator. ### Claim 9 A communication security method of a second node, the communication security method comprising: transmitting first information to a first node at a previous time, the previous time being recognized by the first node and the second node; receiving encrypted second information from the first node at a next time; and decrypting the encrypted second information using the first information and information on the previous time. ### Claim 10 (depends on 9) The communication security method of claim 9, wherein the decrypting comprises decoding the second information based on the first information. ### Claim 11 (depends on 9) The communication security method of claim 9, wherein the previous time is repeated periodically or aperiodically. ### Claim 12 (depends on 9) The communication security method of claim 9, wherein a near field comprises the first node and the second node that communicate with each other based on a full duplex communication scheme. ### Claim 13 (depends on 12) The communication security method of claim 12, further comprising: determining whether a third node exists within the near field, the third node being distinguished from the first node. ### Claim 14 (depends on 13) The communication security method of claim 13, wherein the determining comprises determining whether the third node exists based on a change in energy in the near field. ### Claim 15 (depends on 9) The communication security method of claim 9, further comprising: receiving an indicator indicating the previous time, wherein the information on the previous time comprises the indicator. ### Claim 16 A communication security apparatus of a first node, the communication security apparatus comprising: a receiving unit configured to receive first information from a second node at a previous time, wherein the previous time is recognized by the first node and the second node; an encrypting unit configured to encrypt second information using the first information and information on the previous time; and a transmitting unit configured to transmit the encrypted second information to the second node at a next time. ### Claim 17 (depends on 14) The communication security apparatus of claim 14, wherein the previous time is repeated periodically or aperiodically. ### Claim 18 (depends on 16) The communication security apparatus of claim 16, wherein a near field comprises the first node and the second node that communicate with each other based on a full duplex communication scheme. ### Claim 19 (depends on 18) The communication security apparatus of claim 18, further comprising: a determining unit configured to determine whether a third node exists within the near field, wherein the third node is distinguished from the second node. ### Claim 20 (depends on 14) The communication security apparatus of claim 14, wherein the information on the previous time comprises an indicator indicating the previous time, and wherein the transmitting unit transmits the indicator. ### Claim 21 A communication security apparatus of a second node, the communication security apparatus comprising: a transmitting unit configured to transmit first information to a first node at a previous time, wherein the previous time is recognized by the first node and the second node; a receiving unit configured to receive encrypted second information from the first node at a next time; and a decrypting unit configured to decrypt the encrypted second information using the first information and information on the previous time. ### Claim 22 (depends on 21) The communication security apparatus of claim 21, wherein the decrypting unit decodes the second information based on the first information. ### Claim 23 (depends on 21) The communication security apparatus of claim 21, wherein the information on the previous time comprises an indicator indicating the previous time, and wherein the receiving unit receives the indicator. ### Claim 24 A computer program embodied on a non-transitory computer readable medium, the computer program being configured to control a processor of a first node to perform: receiving first information from a second node at a previous time, the previous time being recognized by the first node and the second node; encrypting second information using the first information and information on the previous time; and transmitting the encrypted second information to the second node at a next time. ### Claim 25 A computer program embodied on a non-transitory computer readable medium, the computer program being configured to control a processor of a second node to perform: transmitting first information to a first node at a previous time, the previous time being recognized by the first node and the second node; receiving encrypted second information from the first node at a next time; and decrypting the encrypted second information using the first information and information on the previous time.