Method of entering a code on a touch surface

Abstract

A method for entering a code comprising a first number of characters onto a touch surface (12). The method comprises the following steps: a) detecting contact made by a user on the touch surface (12), b) emitting by the touch surface (12) a series of at least one counting vibration (26, 28, 30, 32) up to a second number of vibrations, c) detecting the cessation of contact after a third number of vibrations between 1 and the second number, d) recording the third number of vibrations corresponding to a character of the code, e) repeating from step a) to step d), until a number of characters equal to the first number is recorded. In the method, when the series of at least one counting vibration comprises at least two vibrations (26, 28, 30, 32), two consecutive vibrations are separated by a time interval of random duration. See Figure 3 for the abbreviation.

Description

Title of the invention: Method for entering a code on a touch surface

[0001] The invention relates to a method for entering a code on a touchscreen. More specifically, the invention relates to the secure entry of a confidential identification code on a touchscreen of an electronic payment terminal by a visually impaired user, for example, a partially sighted or blind user. The invention also relates to a payment method comprising the steps of the entry method, as well as to an electronic payment terminal for implementing the entry method.

[0002] It is difficult for a visually impaired person to enter their PIN confidentially on an electronic payment terminal. Indeed, using a virtual keyboard on a touchscreen requires that the on-screen keys be visually detected. Voice commands are not feasible because a malicious person could intercept the PIN. There are devices that can be added to the terminal to communicate with it in Braille, but these systems are complex to implement because they require the installation of an additional component on the terminal.

[0003] A method for entering a personal identification number (PIN, also called a PIN code) that does not require the installation of an additional component for use by a visually impaired user is already known in the prior art, as described in US patent 10489567. To do this, the user interacts with the touch surface by applying varying levels of pressure to the touch surface for a specific period of time. Each character of the code corresponds to a specific pressure level applied for a specific duration. The change in pressure indicates to the terminal that a character of the code has been entered and that the entry of another character of the code has begun. The user signals that the code entry is complete by releasing pressure.Thus, the user enters the code without having to lift their finger or stylus from the surface, preventing malicious individuals from obtaining it, for example, simply by timing how long a character is pressed. However, such a method is complex to implement because the user must concentrate on the elapsed time and the level of pressure applied.

[0004] The invention aims in particular to provide a method that is easier to implement artwork.

[0005] To this end, the invention relates to a method for entering a code on a touch surface, comprising a first number of characters, preferably four characters, comprising the following steps: a) detection of contact exerted by a user on the touch surface, b) emission by the touch surface of a series of at least one counting vibration, which may go up to a second number of counting vibrations, c) detection of contact termination after a third vibration count number between 1 and the second number, d) recording of the third number of counting vibrations that corresponds to a character of the code, e) resume at step a) up to step d), until a number of characters equal to the first number is recorded, method in which, when the series of at least one counting vibration includes at least two counting vibrations, two consecutive counting vibrations are separated by a time interval whose duration is random.

[0006] Haptic feedback is thus used, allowing the user to be guided in the counting necessary for code entry. Code entry by the visually impaired user, or by any other user, is therefore simplified. Indeed, the user is only required to maintain pressure while counting the vibrations until the number of vibrations corresponds to the character to be entered, and then release the pressure. This improves the entry result, i.e., it promotes the entry of a correct code.

[0007] Furthermore, the process requires a fairly simple process implementation device, which must not discriminate between different pressure levels.

[0008] Because of the random interval, the time required to enter a character is unknown, and a malicious person cannot identify a character simply by timing the press. This enhances the security of the process.

[0009] The characters of the code can be numbers or letters, or even special characters such as symbols.

[0010] Depending on other optional features of the process, taken alone or in combination:

[0011] - The touch surface is a touch surface of an electronic payment terminal. The The code could be a confidential identification code.

[0012] - The method further comprises, after step a) and before step b) a step during which a first vibration of constant amplitude is emitted, called the first calibration vibration, followed by a second vibration whose amplitude is decreasing, called the second calibration vibration. Thus, before entering characters, the user is allowed to familiarize themselves with vibrations emitted by the touch surface and is informed that input is about to begin. This step allows for "sensory calibration," as demonstrated, for example, by the work of the Vibrations Acoustics laboratory at FINS A in Lyon. This promotes the entry of a correct code. Advantageously, each of these calibration vibrations lasts approximately one second. Typically, the first calibration vibration has a frequency of 200 Hz with an amplitude of 100%, while the second calibration vibration has a decreasing amplitude from 100% to 0%. The vibrations are generally emitted by a haptic actuator, such as a linear resonant actuator (LRA). For such an LRA, the amplitude of 100% is, for example, 1.2 g, or 11.76798 m / s². For an LRA, the amplitude can range from 0.8 to 5 g depending on its size. Piezoelectric oscillators have acceleration amplitudes that can reach several g, depending on their size.

[0013] - During step b), the counting vibrations are separated by an interval of random time, between 0.1 and 2 seconds, preferably between 0.2 and 1 second. During step b), the counting vibrations are separated by a time interval of 0.1 to 3 seconds, preferably 0.2 to 1.5 seconds. Thus, the time spent entering the code is not too long, but the intervals are long enough for the user to release pressure at the right moment. This reduces the risk of typing errors. User comfort is good, while input efficiency is adequate. Furthermore, the random duration parameter adds entropy to the code, thereby reducing the chances of a potential hacker guessing it.

[0014] - During step b), the counting vibrations are emitted at a frequency ranging from 100 to 300Hz, preferably 200 Hz.

[0015] - During step b), each counting vibration is emitted for a duration between 0.1 and 2 seconds, preferably between 0.2 and 1 second.

[0016] Thus, this makes it possible to participate in increasing the entropy of the code so as to improve the security of the process by reducing the possibilities for a possible hacker to guess the code.

[0017] - During step b), the amplitude of the counting vibration increases up to a maximum, then decreases. In one example, the amplitude increases linearly up to the maximum, then decreases linearly.

[0018] - At the end of step c) and before step e), the touch surface emits at least one vibration. Preferably, the touch surface emits a random number of vibrations after contact has ceased. These decoy vibrations are not perceived by The user, only the terminal, knows when the user removed their finger. Therefore, using an accelerometer attached to the terminal would prevent a malicious person from guessing the entered code. This increases the entropy of the code.

[0019] The invention also relates to a payment method comprising the steps of the confidential code entry process as described above, further comprising at least one of the following steps: - prior to step a), verbal statement of the transaction amount, - after step e), issuance of a voice message informing of the outcome of the seizure.

[0020] The invention also relates to an electronic payment terminal comprising a touch surface configured to implement the method of entering a code as described above, the touch surface being equipped with a haptic actuator configured to execute step b) of the method. A haptic actuator can be, for example, a piezoelectric actuator, a linear resonant actuator (LRA) that uses a magnetic mass suspended by springs, or a vibrating motor with an eccentric rotating mass. The piezoelectric actuator has the advantage of being compact and having a wide frequency range (remaining effective between 50 and 1000 Hz). If necessary, the haptic actuator is also configured to emit first and second calibration vibrations. Brief description of the figures

[0021] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0022] [Fig-1] illustrates different stages of a code entry process according to a method of realization of the invention;

[0023] [Fig.2] illustrates the evolution over time of vibrations emitted during a step illustrated in [Fig.1];

[0024] [Fig.3] illustrates other steps of the process shown in [Fig.1];

[0025] [Fig.4] illustrates the evolution over time of vibrations emitted during the illustrated steps on the [Fig.3]. Detailed description

[0026] Figures 1 and 3 illustrate different stages of a code entry method according to the method of the invention, during which an electronic payment terminal 10 is operated by a user. Prior to these stages, a transaction amount was entered by a merchant. If necessary, the merchant performed the steps required to enable the entry to be carried out using the method according to the invention. More specifically, the merchant launched an application enabling the implementation of the method. For use by a visually impaired person, the amount of The transaction can be announced verbally. When entering the code, the user can be guided verbally. The code to be entered includes an initial number of characters. For example, the code consists of 4 digits, and these digits are integers ranging from 0 to 9. The PIN entry process for the blind person must be ergonomic (minimizing user errors, for example), but also secure (a potential hacker must have great difficulty extracting the entered code).

[0027] The terminal 10 includes a smart card reader and a magnetic stripe card reader, not shown. It also includes a touch surface 12, allowing, in particular, the display of information such as transaction amounts, and the entry of these same amounts as well as customers' confidential identification codes. The terminal 10 also includes electronic components housed in one or more secure enclosures, not shown. All these components are contained within a housing 14. The touch surface 12 of the electronic payment terminal 10 according to the invention includes a haptic actuator, not visible in the figures. The haptic actuator is configured to allow the touch surface 12 to emit vibrations during steps of the data entry process.

[0028] In Figures 1 and 3, the terminal 10 is shown in the hands 16 of a user. More specifically, during the various stages, the casing 14 of the terminal 10 rests in the user's hands 16.

[0029] Figure 1 illustrates three steps in the input process, during which sensor calibration is performed. These steps take place prior to code entry.

[0030] First, the user takes hold of the terminal 10, step P, i.e. the casing 14 of the terminal 10 rests in his hands, and the hands 16 are in contact with the casing 14. During this step P, the hands 16 are not in contact with the touch surface 12.

[0031] The user is asked to make contact with the touch surface 12. Contact is made by means of a finger 18 of the user, step CC. It could also be made by means of a stylus. The user can make this contact anywhere on the touch surface 12. The finger 18 thus makes contact with the touch surface 12, step CC, which is symbolized by reference numeral 20. The contact 20 is maintained during the step following step CC.

[0032] Following step CC, step a) of the process according to the invention is carried out, during which there is detection of the contact exerted by the user on the touch surface 12.

[0033] Upon detection of the contact 20, a first calibration vibration 22 is emitted, followed by a second calibration vibration 24, during the VC step.

[0034] Figure 2 illustrates the evolution over time, expressed in seconds, of the amplitude of vibrations 22 and 24, expressed in m / s². As illustrated in Figure 2, the first calibration vibration 22 is continuous, meaning its amplitude is constant. The amplitude of the second calibration vibration 24 decreases from 100% to 0%. Each of these vibrations 22 and 24 lasts approximately one second. In Figure 2, the first vibration 22 has a frequency of 200 Hz and an amplitude of 100%, while the second vibration 24 has a decreasing amplitude from 100%. Thus, before entering characters, the user is allowed to familiarize themselves with vibrations emitted by the touch surface and is informed that the input process is about to begin.

[0035] After a random duration, between 0.5 and 5 seconds (preferably 2 seconds), code entry can begin. This random duration increases the entropy of the code.

[0036] Figure 3 illustrates the entry of the numeric character "4" using the entry method according to the invention. Figure 3 represents a case in which the digit "4" is not the first character of the code. It follows another character that has already been entered. Therefore, contact 20 has been stopped, step P. If, in another undescribed case, the digit "4" were the first character of the code, its entry would be performed directly after the sensor calibration step described in Figures 1 and 2, and the finger 18 would already be in contact 20 with the touch surface 12, step C1 of contact between the user's finger 18 and the touch surface 12. In this other case, contact 20 would have been maintained since calibration, for 1 second as specified above.

[0037] During step Cl, the contact 20 is established in the same way as in step CC. Step a) of the method according to the invention is then carried out, during which the contact 20 exerted by the user on the touch surface 12 is detected.

[0038] Following the detection of the contact 20, step b) of the method according to the invention is carried out, during which the touch surface 12 emits a series of at least one counting vibration 26, which may be increased to a second number of vibrations. The counting vibrations 26 encode each character of the code, for example, each digit from 0 to 9 of a 4-digit code. Each of these digits is encoded by a specific number of vibrations. For example, the number of vibrations encoding a digit is equal to the digit it encodes. Thus, "9" is encoded by nine vibrations. In the example described, "0" is encoded by 10 vibrations. Thus, to encode a digit, a series of at least one counting vibration is emitted, which in this example may be increased to a second number of vibrations equal to 10. A third number of counting vibrations, between 1 and 10, corresponding to the character to be entered, is then emitted.In one embodiment, and this is to allow deceiving a malicious person, . The number of vibration sequences can also be greater than 10. Thus, if the user lifts their finger on the 12th vibration, the retained digit will be 2 (1 for 11 vibrations, 2 for 12, 3 for 13, etc.). This makes it more difficult for someone with malicious intent to guess the lower-value digits. This reinforces the entropy across the entire set of digits. The user can, for example, choose to stop at 23 to enter the digit 3. Therefore, if a character in the code is a digit, the number of counting vibrations corresponding to that character can be equal to the number of vibrations or to the number of vibrations modulo 10.

[0039] In the example of [Fig. 3], the digit “4” is entered as follows. During steps VI, V2, V3, and V4, a counting vibration 26, 28, 30, and 32 are emitted, respectively. As shown in [Fig. 4], the counting vibrations 26, 28, 30, and 32 are separated by a time interval D1, D2, and D3. The time intervals D1, D2, and D3 each occur during a contact step, C2, C3, and C4, respectively, during which contact 20 is maintained but there is no vibration.

[0040] When the number of counting vibrations emitted corresponds to the third number, here "4", the user stops the contact 20, step P, in which the hands 16 are not in contact with the touch surface 12. Step c) of the method according to the invention is then carried out, during which the stopping of the contact 20 is detected after the third number of vibrations.

[0041] We then proceed to step d) of the process, that is to say there is recording of the third number of counting vibrations, here "4", which corresponds to the character of the code entered, here "4".

[0042] In one embodiment, and to increase the entropy of the code, the terminal can continue to emit a random number of vibrations even after the user's finger is no longer in contact with the touch surface. These decoy vibrations are not perceived by the user; only the terminal knows when the user removed their finger. Thus, the use of an accelerometer, attached to the terminal, would prevent a malicious person from guessing the entered code.

[0043] To enter the following characters of the code, we start again from step a) up to step d), until a number of characters equal to the first number, 4 characters in the example, has been recorded.

[0044] As shown in [Fig. 4], in the example the series of at least one counting vibration comprises at least two counting vibrations, more precisely four vibrations 26, 28, 30, and 32, and two consecutive counting vibrations are separated by a time interval D1, D2, D3 whose duration is random. Indeed, the durations D1, D2, and D3 are different from each other. Due to the interval of random duration, the time required to capture a character and a person is unknown. Malicious software cannot identify a character by simply timing the press duration.

[0045] In the example, the counting vibrations 26, 28, 30 and 32 are separated by a time interval D1, D2, D3 of a duration of 1 second, 0.85 seconds and 3 seconds respectively.

[0046] In the example, during step b), each counting vibration 26, 28, 30 and 32 is emitted for a duration of between 0.8 and 1.6 seconds.

[0047] In the example, during step b), the amplitude of the counting vibration changes from 0 to 100%, then decreases to 0%. For better ergonomics, the vibration amplitude should change from 0 to 100% in the shortest possible time.

[0048] The steps of the data entry process are part of a payment process which also includes the following steps: - prior to step a), verbal statement of the transaction amount, - after step e), sending a voice message informing of the outcome of the entry.

[0049] The invention is not limited to the embodiments shown, and other embodiments will be obvious to those skilled in the art. In particular, it is possible to implement the method without resorting to sensory calibration steps. Reference list

[0050] 10: electronic payment terminal 12: Touch surface 14: case 16: hands 18: finger 20: contact 22: First calibration vibration 24: Second calibration vibration 26: first counting vibration 28: second counting vibration 30: third counting vibration 32: fourth counting vibration P: handling step CC: Contact step for calibration VC: vibration stage during calibration C1, C2, C3, C4: contact stages during counting VI, V2, V3, V4: vibration stages during counting

Claims

Demands

1. A method for entering a code on a touch surface (12) comprising a first number of characters, preferably four characters, comprising the following steps: a) detecting contact made by a user on the touch surface (12), b) emitting by the touch surface (12) a series of at least one counting vibration (26, 28, 30, 32) which may be up to a second number of counting vibrations, c) detecting the cessation of contact after a third number of counting vibrations between 1 and the second number, d) recording the third number of counting vibrations which corresponds to a character of the code, e) repeating from step a) to step d), until a number of characters equal to the first number is recorded, wherein, when the series of at least one counting vibration includes at least two counting vibrations (26, 28, 30, 32),two consecutive counting vibrations are separated by a time interval (D1, D2, D3) of random duration, in which, at the end of step c) and before step e), the touch surface (12) emits at least one vibration.

2. A method of input according to claim 1, wherein the touch surface (12) is a touch surface of an electronic payment terminal (10).

3. A gripping method according to any one of claims 1 and 2, further comprising after step a) and before step b) a step during which a first vibration of constant amplitude (22) is emitted, called the first calibration vibration, followed by a second vibration (24) whose amplitude is decreasing, called the second calibration vibration.

4. A grasping method according to any one of the preceding claims, wherein in step b), the counting vibrations (26, 28, 30, 32) are separated by a time interval (D1, D2, D3) of a duration ranging from 0.1 to 3 seconds, preferably 0.2 to 1.5 seconds.

5. A gripping method according to any one of the preceding claims, wherein in step b), the vibrations of counting (26, 28, 30, 32) are emitted at a frequency ranging from 100 to 1000 Hz, preferably 200 Hz.

6. A grasping method according to any one of the preceding claims, wherein in step b), each counting vibration (26, 28, 30, 32) is emitted for a duration of 0.1 to 2 seconds, preferably 0.2 to 1 second.

7. A grasping method according to any one of the preceding claims, wherein during step b), the amplitude of the counting vibration increases to a maximum, then decreases.

8. Payment method comprising the steps of the method of entering a confidential code according to any one of claims 1 to 7, further comprising at least one of the following steps: - prior to step a), verbal announcement of the amount of the transaction, - after step e), transmission of a voice message informing of the outcome of the entry.

9. Electronic payment terminal (10) comprising a touch surface (12) configured to implement the method of entering a code according to any one of claims 1 to 7, the touch surface (12) being equipped with a haptic actuator configured to perform step b) of the method.

Images