US-12627401-B2 - Apparatus and method for transmitting and receiving covert message in wireless communication

US12627401B2US 12627401 B2US12627401 B2US 12627401B2US-12627401-B2

Abstract

Disclosed herein are an apparatus and method for transmitting a covert message in wireless communication. The apparatus for transmitting a covert message in wireless communication may be configured to, in a covert message in which a data frame is composed of a Start Frame Delimiter (SFD), a header, a payload, and a Cyclic Redundancy Check (CRC), transmit the SFD of the covert message corresponding to a first sequence number masked with a preset SFD mask length, transmit the header of the covert message corresponding to a second sequence number masked with a preset header mask length, transmit the payload of the covert message corresponding to a third sequence number masked with a preset payload mask length, and transmit the CRC of the covert message corresponding to a fourth sequence number masked with a preset CRC mask length.

Inventors

Sang-Woo Lee
Yong-Sung Jeon
Ha-Young SEONG
You-Sung Kang
Ik-Kyun Kim

Assignees

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE

Dates

Publication Date: 20260512
Application Date: 20230711
Priority Date: 20221123

Claims (15)

1 . An apparatus for transmitting a covert message in wireless communication, comprising: one or more processors; and an execution memory configured to store at least one program that is executed by the one or more processors, wherein the at least one program is configured to: in a covert message in which a data frame is composed of a Start Frame Delimiter (SFD), a header, a payload, and a Cyclic Redundancy Check (CRC), transmit the SFD of the covert message corresponding to a first sequence number masked with a preset SFD mask length, transmit the header of the covert message corresponding to a second sequence number masked with a preset header mask length, transmit the payload of the covert message corresponding to a third sequence number masked with a preset payload mask length, and transmit the CRC of the covert message corresponding to a fourth sequence number masked with a preset CRC mask length, wherein the at least one program is configured to, when the masked first sequence number does not match the SFD, transmit the SFD depending on whether a new first sequence number obtained by increasing a value of the first sequence number corresponds to the SFD.
2 . The apparatus of claim 1 , wherein the at least one program is configured to, when the masked second sequence number does not match the header, transmit the header depending on whether a new second sequence number obtained by increasing a value of the second sequence number corresponds to the header.
3 . The apparatus of claim 2 , wherein the at least one program is configured to, when the masked third sequence number does not match the payload, transmit the payload depending on whether a new third sequence number obtained by increasing a value of the third sequence number corresponds to the payload.
4 . The apparatus of claim 3 , wherein the at least one program is configured to transmit the payload corresponding to the third sequence number until a number of transmissions corresponding to a number of bytes set in a length field of the header are completed.
5 . The apparatus of claim 3 , wherein the at least one program is configured to, when the masked fourth sequence number does not match the CRC, transmit the CRC depending on whether a new fourth sequence number obtained by increasing a value of the fourth sequence number corresponds to the CRC.
6 . An apparatus for receiving a covert message in wireless communication, comprising: one or more processors; and an execution memory configured to store at least one program that is executed by the one or more processors, wherein the at least one program is configured to: in a covert message in which a data frame is composed of a Start Frame Delimiter (SFD), a header, a payload, and a Cyclic Redundancy Check (CRC), receive the data frame of the covert message, and store the data frame as the SFD when a sequence number of the data frame corresponds to a first sequence number of the SFD, receive the data frame of the covert message, and store the data frame as the header when the sequence number of the data frame corresponds to a second sequence number of the header, receive the data frame of the covert message, and store the data frame as the payload when the sequence number of the data frame corresponds to a third sequence number of the payload, receive the data frame of the covert message, and store the data frame as the CRC when the sequence number of the data frame corresponds to a fourth sequence number of the CRC, and compose the covert message from the stored SFD, header, payload, and CRC, wherein the at least one program is configured to mask the sequence number of the data frame with a preset SFD mask length and store the data frame having the masked sequence number as the SFD.
7 . The apparatus of claim 6 , wherein the at least one program is configured to mask the sequence number of the data frame with a preset header mask length and store the data frame having the masked sequence number as the header.
8 . The apparatus of claim 7 , wherein the at least one program is configured to mask the sequence number of the data frame with a preset payload mask length and store the data frame having the masked sequence number as the payload.
9 . The apparatus of claim 8 , wherein the at least one program is configured to store the payload until a number of receptions corresponding to a number of bytes in the payload set in a length field of the header are completed.
10 . The apparatus of claim 8 , wherein the at least one program is configured to mask the sequence number of the data frame with a preset CRC mask length and store the data frame having the masked sequence number as the CRC.
11 . A method for transmitting a covert message in wireless communication, the method being performed by an apparatus for transmitting a covert message in wireless communication, the method comprising: in a covert message in which a data frame is composed of a Start Frame Delimiter (SFD), a header, a payload, and a Cyclic Redundancy Check (CRC), transmitting the SFD of the covert message corresponding to a first sequence number masked with a preset SFD mask length; transmitting the header of the covert message corresponding to a second sequence number masked with a preset header mask length; transmitting the payload of the covert message corresponding to a third sequence number masked with a preset payload mask length; and transmitting the CRC of the covert message corresponding to a fourth sequence number masked with a preset CRC mask length, wherein transmitting the SFD comprises: when the masked first sequence number does not match the SFD, transmitting the SFD depending on whether a new first sequence number obtained by increasing a value of the first sequence number corresponds to the SFD.
12 . The method of claim 11 , wherein transmitting the header comprises: when the masked second sequence number does not match the header, transmitting the header depending on whether a new second sequence number obtained by increasing a value of the second sequence number corresponds to the header.
13 . The method of claim 12 , wherein transmitting the payload comprises: when the masked third sequence number does not match the payload, transmitting the payload depending on whether a new third sequence number obtained by increasing a value of the third sequence number corresponds to the payload.
14 . The method of claim 13 , wherein transmitting the payload further comprises: transmitting the payload corresponding to the third sequence number until a number of transmissions corresponding to a number of bytes set in a length field of the header are completed.
15 . The method of claim 13 , wherein transmitting the CRC comprises: when the masked fourth sequence number does not match the CRC, transmitting the CRC depending on whether a new fourth sequence number obtained by increasing a value of the fourth sequence number corresponds to the CRC.

Description

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of Korean Patent Application No. 10-2022-0158051, filed Nov. 23, 2022, which is hereby incorporated by reference in its entirety into this application. BACKGROUND OF THE INVENTION 1. Technical Field The present disclosure relates generally to covert channel technology in wireless communication, and more particularly to an apparatus and method for transmitting and receiving a covert message in wireless communication. 2. Description of the Related Art Wireless communication is divided into communication based on an overt channel and communication based on a covert channel. The overt channel refers to a channel through which communication is performed based on normal communication standards (specifications). In contrast, the covert channel refers to a hidden communication channel that is not disclosed to the general public without using a transmission method based on existing communication protocol standards. Covert message transmission technology using the covert channel is a communication technique used when it is not possible to transmit data by encapsulating the data in the payload of a typical communication protocol. Covert channel technology is divided into a covert timing channel and a covert storage channel. The covert timing channel is a scheme for transmitting covert information using the timing information of normal traffic. That is, a transmitter may transmit covert information by adjusting the transmission time interval between normal packets when the normal packets are transmitted at regular intervals. The covert storage channel is a scheme for directly storing covert information in network traffic. That is, this is a scheme for inserting covert information into the protocol header or body area of a packet and transmitting the packet. The covert timing channel may be detected through a statistical analysis or the like on the time axis of a packet. However, since the covert storage channel is problematic in that data in the header and body areas may be extracted and can be detected through a statistical analysis. Meanwhile, Korean Patent No. 10-2227317 entitled “Wi-Fi Physical (PHY) layer multi-band covert channel detector” discloses a Wi-Fi PHY layer multi-band covert channel detector, which simultaneously receives Wi-Fi signals through multiple communication channels, separates the Wi-Fi signals into logical multi-channel signals, and transfers the separated channel signals to a PHY layer multi-band covert channel detection unit. SUMMARY OF THE INVENTION Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the prior art, and an object of the present disclosure is to covertly transmit data without exposing data to a malicious terminal when the malicious terminal is present on a network. Another object of the present disclosure is to prevent data leakage from occurring through a malicious terminal when the malicious terminal on the network monitors the payload of a protocol. In accordance with an aspect of the present disclosure to accomplish the above objects, there is provided an apparatus for transmitting a covert message in wireless communication, including one or more processors, and execution memory configured to store at least one program that is executed by the one or more processors, wherein the at least one program is configured to, in a covert message in which a data frame is composed of a Start Frame Delimiter (SFD), a header, a payload, and a Cyclic Redundancy Check (CRC), transmit the SFD of the covert message corresponding to a first sequence number masked with a preset SFD mask length, transmit the header of the covert message corresponding to a second sequence number masked with a preset header mask length, transmit the payload of the covert message corresponding to a third sequence number masked with a preset payload mask length, and transmit the CRC of the covert message corresponding to a fourth sequence number masked with a preset CRC mask length. The at least one program may be configured to, when the masked first sequence number does not match the SFD, transmit the SFD depending on whether a new first sequence number obtained by increasing a value of the first sequence number corresponds to the SFD. The at least one program may be configured to, when the masked second sequence number does not match the header, transmit the header depending on whether a new second sequence number obtained by increasing a value of the second sequence number corresponds to the header. The at least one program may be configured to, when the masked third sequence number does not match the payload, transmit the payload depending on whether a new third sequence number obtained by increasing a value of the third sequence number corresponds to the payload. The at least one program may be configured to transmit the payload corresponding to the third sequence number until a number of