# US 10,313,332 B2 · Method of performing one-time password (OTP) authentication using color code and OTP authentication server using color code > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,332 B2 - Document ID: US10313332B2 - Status: Granted - Kind: B2 - Application number: 15/251,033 - Filed: 2016-08-30 - Published: 2017-03-16 - Granted: 2019-06-04 - Earliest claimed: 2015-09-16 - Assignees: Research & Business Foundation Sungkyunkwan University - Applicants: Research & Business Foundation Sungkyunkwan University - Inventors: Kwang-Seok Hong; Sang Min Park - Web page: https://patentgrep.com/patent/US10313332B2 ## CPC - H04L 63/0838: {using one-time-passwords} - H04W 12/068: {using credential vaults, e.g. password manager applications or one time password [OTP] applications} - H04L 63/0853: {using an additional device, e.g. smartcard, SIM or a different communication terminal (cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234)} - H04W 12/06: Authentication - H04W 12/77: Graphical identity - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method of performing one-time password (OTP) authentication using a color code is provided. The method includes generating, by an OTP terminal and an authentication server, an OTP using a reference time, generating, by the OTP terminal, a color code corresponding to a binary code representing the OTP, displaying, by a display device, the color code, obtaining, by a camera, the displayed color code, decoding, by the authentication server, the obtained color code into the color code and generating a password which refers to the decoded binary code, and performing, by the authentication server, authentication by comparing the generated OTP and the password. ## Claims ### Claim 1 A method of performing one-time password (OTP) authentication, comprising: generating, by an OTP terminal and an authentication server, an OTP using a reference time; generating, by the OTP terminal, a color code corresponding to a binary code representing the OTP; changing, by the OTP terminal, a color scheme of the color code, in response to the reference time elapsing; displaying, by a display device, the color code; obtaining, by a camera, the displayed color code; determining, by the authentication server, that a user is authenticated, in response to detecting a match between the generated OTP and a password represented by the color code; and in response to the determining that the user is authenticated, approving a transaction at an ATM machine, approving a credit card transaction, or sending a signal to open or close a door of the ATM machine, wherein the OTP terminal generates the color code by adding a dummy color at a specific position of the color code based on the reference time, and the authentication server decodes the generated color code into the binary code by considering the dummy color added at the specific position of the color code according to the reference time. ### Claim 2 (depends on 1) The method of claim 1, wherein the color code is configured as a first color corresponding to 0 and a second color corresponding to 1 with respect to a series of binary numbers configuring the binary code. ### Claim 3 (depends on 1) The method of claim 1, wherein the OTP terminal includes a code table in which different colors are matched to binary sequences configured as two-or-more digit binary numbers, respectively, and converts the binary code into the color code using the code table. ### Claim 4 (depends on 1) The method of claim 1, wherein the display device sequentially displays the color code in a predetermined region according to a sequence of characters and a sequence of a binary code configuring the OTP. ### Claim 5 (depends on 4) The method of claim 4, wherein the display device changes a position of a region displaying the color code according to the reference time, and the authentication server decodes the binary code in consideration of the changed position of the region according to the reference time in an image obtained by the camera. ### Claim 6 (depends on 1) The method of claim 1, wherein the authentication server decodes the obtained color code into the binary code based on the reference time. ### Claim 7 (depends on 1) The method of claim 1, further comprising: generating, by the authentication server, the password by decoding the color code obtained by the camera into the binary code. ### Claim 8 (depends on 1) The method of claim 1, further comprising: generating, by the display device, the password by decoding the color code obtained by the camera into the binary code. ### Claim 9 (depends on 1) The method of claim 1, wherein the OTP is generated using a HMAC-based cipher generation algorithm that generates a new cryptogram using a key value and a counter value, and truncates a predetermined number of digits after substituting the key value and the counter value into the algorithm. ### Claim 10 (depends on 1) The method of claim 1, wherein the determining that the user is authenticated comprises detecting a HSV (hue saturation value) for each of pixels included in cells of the obtained color code, and recognizing respective colors of the pixels based on the HSV. ### Claim 11 (depends on 10) The method of claim 10, wherein the determining that the user is authenticated further comprises recognizing a color for each of the cells as a most common color, among the recognized colors, in each cell, and decoding the color code, based on the recognized color, to generate the password. ### Claim 12 A one-time password (OTP) authentication server, comprising: an OTP generation hardware processor configured to generate an OTP according to a reference time; a communication module hardware processor configured to receive an image generated by capturing a display screen on which a color code is displayed; a storage device configured to store a code table; a central processing unit (CPU) configured to detect, for each pixel included in a cell of the image, a Hue Saturation Value (HSV), recognize a color being present in a maximum number of pixels in each of cells based on the detected HSV, extract the color code from the image based on the recognized color, convert the color code into a series of binary codes using the code table, and determine that a user is authenticated, in response to detecting that a match between the generated OTP and a password represented by the color code, wherein, in response to the determination that the user is authenticated, the OTP authentication server approves a transaction at an ATM machine, approves a credit card transaction, or sends a signal to open or close a door of the ATM machine, wherein a color scheme of the color code changes, in response to the reference time elapsing, and wherein the color code is generated by adding a dummy color at a specific position of the color code based on the reference time, and the CPU decodes the generated color code into the binary code by considering the dummy color added at the specific position of the color code according to the reference time. ### Claim 13 (depends on 12) The OTP authentication server of claim 12, wherein the CPU converts the color code into the binary code while excluding the dummy color located at the specific position of the color code according to the reference time. ### Claim 14 (depends on 12) The OTP authentication server of claim 12, wherein the code table includes information in which the color matching the binary number or the binary sequence is changed according to the reference time. ### Claim 15 (depends on 12) The OTP authentication server of claim 12, wherein the image includes the color code in a predetermined region according to a sequence of characters configuring the OTP and a sequence of a binary code corresponding to the characters. ### Claim 16 (depends on 15) The OTP authentication server of claim 15, wherein the CPU sets a position of the region or a sequence of a region in which the color code is output to be different according to the reference time, and converts the color code into the binary code. ### Claim 17 (depends on 12) The method of claim 12, wherein in response to the determination that the user is authenticated, the OTP authentication server sends a signal to cause the ATM machine to dispense cash. ### Claim 18 A one-time password (OTP) terminal, comprising: one or more hardware processors configured to: generate, along with an authentication server, an OTP using a reference time; generate a color code corresponding to a binary code representing the OTP; change a color scheme of the color code, in response to the reference time elapsing; and obtain, from a camera, a color code displayed on a display device, wherein the authentication server determines that a user is authenticated, in response to detecting a match between the generated OTP and a password represented by the color code, wherein in response to the determination that the user is authenticated, a transaction at an ATM machine is approved, a credit card transaction is approved, or a signal is sent to open or close a door of the ATM machine, and wherein the color code is generated by adding a dummy color at a specific position of the color code based on the reference time, and the authentication server decodes the generated color code into the binary code by considering the dummy color added at the specific position of the color code according to the reference time. ### Claim 19 (depends on 18) The OTP terminal of claim 18, wherein the processor is further configured to use a code table including information in which the color matching the binary number or the binary sequence is changed according to the reference time. ### Claim 20 (depends on 18) The OTP terminal of claim 18, wherein the reference sequence includes a sequence of characters configuring the OTP and a sequence of a binary code corresponding to the characters. ### Claim 21 (depends on 18) The OTP terminal of claim 18, wherein the display device displays a position of the specific region or a sequence of the specific region in which the color code is displayed to be different according to the reference time.