# US 10,320,518 B2 · Apparatus and method for preventing information leakage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,518 B2 - Document ID: US10320518B2 - Status: Granted - Kind: B2 - Application number: 15/807,917 - Filed: 2017-11-09 - Published: 2018-07-05 - Granted: 2019-06-11 - Earliest claimed: 2016-12-29 - Assignees: Electronics and Telecommunications Research Institute - Applicants: Electronics and Telecommunications Research Institute - Inventors: Hui-Rae Cho; Jin-Hyun Kim; In-Ho Hwang; Sae-Hoon Ju; Kyung-Hoon Lee - Web page: https://patentgrep.com/patent/US10320518B2 ## CPC - H04K 3/68: {using passive jamming, e.g. by shielding or reflection (shielding of apparatus or components against electric or magnetic field H05K9/00)} - H04L 27/2602: {Signal structure} - H04L 27/2614: {Peak power aspects} - H04L 27/2628: {Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators (H04L27/2634 takes precedence)} - H04K: SECRET COMMUNICATION; JAMMING OF COMMUNICATION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An apparatus and a method for preventing an information leakage. The apparatus for preventing the information leakage includes a shielding signal pattern generation unit configured to generate a shielding signal pattern including a radiation band and a radiation suppression band; a shielding signal generation unit configured to generate an electromagnetic leakage shielding signal corresponding to an Orthogonal Frequency Division Multiplexing (OFDM) scheme by using the shielding signal pattern; a signal amplification unit configured to amplify a transmitting power of the electromagnetic leakage shielding signal; and an antenna unit configured to transmit the amplified electromagnetic leakage shielding signal. ## Claims ### Claim 1 An apparatus for preventing an information leakage, comprising: a shielding signal pattern generation unit configured to generate a shielding signal pattern including a radiation band and a radiation suppression band; a shielding signal generation unit configured to generate an electromagnetic leakage shielding signal corresponding to an Orthogonal Frequency Division Multiplexing (OFDM) scheme by using the shielding signal pattern; a signal amplification unit configured to amplify a transmitting power of the electromagnetic leakage shielding signal; and an antenna unit configured to transmit the amplified electromagnetic leakage shielding signal, wherein the shielding signal pattern generation unit generates the shielding signal pattern of a sample rate band including an operating frequency band, a guard frequency band, and an image frequency band. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the shielding signal pattern generation unit generates the shielding signal pattern in a time domain by performing an Inverse Fast Fourier Transform (IFFT) on the sample rate band of a complex conjugated mirror form. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the operating frequency band includes the at least one radiation band and the radiation suppression band. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the shielding signal pattern generation unit assigns a valid subcarrier to the radiation band, and generates the shielding signal pattern by nulling at least one of the radiation suppression band, the guard frequency band, and the image frequency band. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the shielding signal pattern generation unit divides the sample rate band into divided sample rate bands, the number of divided sample rate bands corresponding to the number of subcarriers, and generates the shielding signal pattern by assigning the valid subcarrier to one or more of the divided sample rate bands and nulling remaining divided sample rate bands except for the divided sample rate bands assigned by the valid subcarrier. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the shielding signal pattern generation unit generates the shielding signal pattern by assigning the valid subcarrier to the image frequency band, the image frequency band being in a complex conjugated mirror relation with the radiation band. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising: a user interface unit for setting at least one of a sample rate band, the radiation band, the radiation suppression band, and the transmitting power by a user. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the shielding signal pattern generation unit optimizes a Peak to Average Power Ratio (PAPR) of the shielding signal pattern. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the shielding signal pattern generation unit generates the shielding signal pattern by assigning a random valid subcarrier to the radiation band, and performs an update with the shielding signal pattern. ### Claim 10 A method of preventing information leakage, comprising: generating a shielding signal pattern including a radiation band and a radiation suppression band; generating an electromagnetic leakage shielding signal corresponding to an Orthogonal Frequency Division Multiplexing (OFDM) scheme by using the shielding signal pattern; amplifying a transmitting power of the electromagnetic leakage shielding signal; and transmitting the amplified electromagnetic leakage shielding signal, wherein the generating the shielding signal pattern generates the shielding signal pattern of a sample rate band including an operating frequency band, a guard frequency band, and an image frequency band. ### Claim 11 (depends on 10) The method of claim 10, wherein the generating the shielding signal pattern generates the shielding signal pattern in a time domain by performing an Inverse Fast Fourier Transform (IFFT) on the sample rate band of a complex conjugated mirror form. ### Claim 12 (depends on 11) The method of claim 11, wherein the operating frequency band includes the at least one radiation band and the radiation suppression band. ### Claim 13 (depends on 12) The method of claim 12, wherein the generating the shielding signal pattern assigns a valid subcarrier to the radiation band, and generates the shielding signal pattern by nulling at least one of the radiation suppression band, the guard frequency band, and the image frequency band. ### Claim 14 (depends on 13) The method of claim 13, wherein the generating the shielding signal pattern divides the sample rate band into divided sample rate bands, the number of divided sample rate bands corresponding to the number of subcarriers, and generates the shielding signal pattern by assigning the valid subcarrier to one or more of the divided sample rate bands and nulling remaining divided sample rate bands except for the divided sample rate bands assigned by the valid subcarrier. ### Claim 15 (depends on 14) The method of claim 14, wherein the generating the shielding signal pattern generates the shielding signal pattern by assigning the valid subcarrier to the image frequency band, the image frequency band being in a complex conjugated mirror relation with the radiation band. ### Claim 16 (depends on 10) The method of claim 10, further comprising: setting at least one of a sample rate band, the radiation band, the radiation suppression band, and the transmitting power by a user. ### Claim 17 (depends on 10) The method of claim 10, wherein the generating the shielding signal pattern optimizes a Peak to Average Power Ratio (PAPR) of the shielding signal pattern. ### Claim 18 (depends on 10) The method of claim 10, wherein the generating the shielding signal pattern generates the shielding signal pattern by assigning a random valid subcarrier to the radiation band, and performs an update with the shielding signal pattern.