GB2632476A - A method of controlling a state of an optically readable security element - Google Patents

Abstract

A switchable optically readable security element 20 is arranged to be switched from a first state to a second state. An image capturing device 10 is arranged to read the security element in the first state or second state to extract a first identity from the security element. In the first and second states, the security element may provide a respective first and second identity. Alternatively, the security element may provide the first identity in one state and no identity and/or is unreadable in the other state. The security element may be switched from the first state to the second state in response to a stimulus applied to the security element and may be returned to the first state in response to a further stimulus or upon removal of the stimulus. The stimulus may be different to the further stimulus. The security element may alternatively be returned to the first state after a preset time. The stimulus may comprise electromagnetic radiation, an electrical field, a magnetic field, a temperature change, a mechanical change, or a chemical change. Switching of the security element from the first state to the second state may be initiated by the image capturing device.

Description

Intellectual Property Office Application No GI323122625 RTM Date 9 February 2024 The following terms are registered trade marks and should be read as such wherever they occur in this document: QR code Intellectual Property Office is an operating name of the Patent Office www.gov.uk /ipo

A METHOD OF CONTROLLING A STATE OF AN OPTICALLY READABLE SECURITY ELEMENT

TECHNICAL FIELD

The present disclosure relates to a method of controlling a switchable optically readable security element, a switchable optically readable security element and a related system.

BACKGROUND

Security elements or tags are used to provide security in relation to an object to which they are attached. These security elements provide security in relation to the object by labelling the object, typically with a single identity. For example, a security element may be encoded with a unique identity that can be extracted from the security element, thereby enabling authentication of the object. However, once the identity of a security element is known, the security provided by the security element is compromised.

Hence, there is a desire to provide a method of controlling an optically readable security element that mitigates against the risk to security provided by the optically readable security element in the event that its identity becomes known and to generally improve upon the identity-related functionality that the optically readable security element provides.

SUM MARY

It is one aim of the present disclosure, amongst others, to provide a method of controlling an optically readable security element which at least partially obviates or mitigates at least some of the disadvantages of the prior art, whether identified herein or elsewhere, or to provide an alternative approach. For instance, it is an aim of embodiments of the invention to provide a method of controlling an optically readable security element that mitigates against the risk to security provided by the optically readable security element in the event that its identity becomes known and to generally improve upon the identity-related functionality that the optically readable element provides.

According to the present invention there is provided a method of controlling a switchable optically readable security element, a switchable optically readable security element and a related system, as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims and the description that follows.

According to a first aspect, there is provided a method of controlling a switchable optically readable security element. The method comprises switching the optically readable security element from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element.

In the first state, the optically readable security element may provide the first identity. In the second state, the optically readable security element may provide a second identity In one of the first state and second state, the optically readable security element may provide the first identity. In the other of the first state and second state, the optically readable security element may provide no identity and/or is unreadable.

The method may further comprise switching the optically readable security element from the first state to the second state in response to a stimulus applied to the optically readable security element.

The method may further comprise returning the optically readable security element to the first state from the second state in response to a further stimulus or removal of the stimulus, optionally, wherein the further stimulus is different to the stimulus.

The method may further comprise returning the optically readable security element to the first state from the second state after a preset time or allowing the optically readable security element to return to the first state from the second state after the preset time.

The switch from the first state may be permanent and/or the second state may be substantially stable over time.

A or the stimulus that causes switching of the optically readable security element from the first state to the second state may comprise at least one of: electromagnetic radiation, an electric field, a magnetic field, a temperature change, a mechanical change and a chemical change.

A or the stimulus that causes switching of the optically readable security element from the first state to the second state may be initiated by the image capturing device.

The optically readable security element may comprise one or more optical emitters arranged to be excited by excitation radiation to cause emission therefrom.

The excitation radiation may be emitted from the image capturing device.

The method may further comprise determining a time taken for the optically readable security element to switch from the first state to the second state and verifying the optically readable security element as authentic based on the time taken.

Verifying the optically readable security element as authentic may comprise comparing the time taken to a time range, and the method may further comprise only verifying the optically readable security element as authentic if the time taken is within the time range.

According to a second aspect, there is provided a switchable optically readable security element. The optically readable security element is arranged to be switched from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element.

According to a third aspect, there is provided a system, comprising a switchable optically readable security element and an image capturing device. The optically readable security element is arranged to be switched from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element. The image capturing device, optionally, wherein a stimulus that causes switching of the optically readable security element from the first state to the second state the stimulus is initiated by the image capturing device.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the invention, and to show how embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying Figures, in which: Figure 1 shows a flowchart for a method of controlling a switchable optically readable security element; Figure 2 shows a system comprising a switchable optically readable security element and an image capturing device; and Figure 3 shows a change of state of the switchable optically readable security element. 30 DETAILED DESCRIPTION Figure 1 shows a flowchart for a method of controlling a switchable optically readable security element. The method of Figure 1 is best understood in conjunction with Figure 2, which shows a system comprising the switchable optically readable security element in a field of view 30 (e.g., in a same image frame) of an image capturing device 10, and Figure 3, which shows a change of state 20a, 20b of the optically readable security element 20. It will be appreciated that the change in state 20a, 20b is shown in Figure 3 in very simplistic terms (via a change of reference numeral), purely to aid understanding of the described concepts.

The method comprises switching S1 the optically readable security element 20 from a first state 20a to a second state 20b, such that (e.g., optional) reading S2 of the optically readable security element 20, using the image capturing device 10, may be undertaken in the first state 20a or the second state 20b to extract a first identity from the optically readable security element 20.

Reading may be performed using sensors (not shown), such as image or video sensors (e.g., those typically included in image capturing devices, such as a camera). It will be understood that the or a reading S2 will of course be important in nearly all practical implementations of the invention, at some point. However, in terms of features core to the invention it is the switching S1 that is key, bringing advantages in relation to earlier or later readings. Accordingly, the reading S2 should be understood as optional in terms of key features (and hence shown in dashed outline in Figure 1).

Switching S1 the optically readable security element 20 means changing an intrinsic (e.g., optical) property thereof, as opposed to, for instance, destroying, damaging or obscuring the optically readable security element 20. In other words, the second state 20b is a state in which the optically readable security element 20 (including optically readable components thereof) has a different intrinsic property compared with the first state 20a. Advantageously, as explained in more detail below, this switching S1 facilitates enhanced security of the optically readable security element 20.

In switching S1 the optically readable security element 20 from the first state 20a to the second state 20b, such that reading S2 of the optically readable security element 20 may be undertaken in either state, typically, the method comprises extracting (e.g., as part of the reading S2) the first identity from the optically readable security element 20 in either the first state 20a or the second state 20b.

In the first state 20a the optically readable security element 20 may provide the first identity, and in the second state 20b the optically readable security element 20 may provide a second identity. It should be noted that the terminology of "first" and "second" is merely labelling and does not imply a temporal relationship between the different states of the optically readable security element 20. Any change of state 20a, 20b is contemplated so long as one state 20a, 20b, at one time is or was readable. For example, there could be a change from any one state to any other state, such that "first" and "second" are purely labels to describe or delineate different states. For instance, there could be additional changes of states, for example, to or from third, fourth, or "n" states.

Advantageously, by switching S1 between states having different identities associated therewith, in the event that one of the identities becomes known, the security provided by the optically readable security element 20 can be maintained (while still enabling authentication of the optically readable security element 20 by means of the first or second identity) by switching S1 the state of the optically readable security element 20 from one of the first state 20a or the second state 20b to the other of the first state 20a and the second state 20b. Relatedly, but perhaps with different benefits, a single optically readable security element 20 can be used to provide more than one identity, which may allow for more functionality in terms of one identity being for one reason, and another identity being for a different reason, or one identity being used to cross-check or confirm the other identity.

In another example, in one of the first state 20a and second state 20b the optically readable security element 20 may provide the first identity, and in the other of the first state 20a and second state 20b the optically readable security element 20 may provide no identity and/or is unreadable (i.e., no identity can be extracted from optically readable security element-the optically readable security element may not always be readable). Advantageously, by switching S1 to a state that does not provide an identity and/or is not readable, the security provided by the optically readable security element 20 can be maintained in the event that the first identity becomes known. This advantage may be especially prominent if, for example, the change in state is stable or permanent (discussed below).

The switching S1 may be in response to a stimulus 22 applied to the optically readable security element 20. Use of a stimulus 22 (e.g., a controlled stimulus, by way of active driving), advantageously, enables precise control of the switching S1. Some examples of the stimulus, all of which relate to and/or affect the (optical) properties of the optically readable security element 20, are listed below: 1. Optical: exposure to a certain frequency of light, which could chemically or mechanically change properties of one or more optical components of the optically readable security element, to impact the optical refraction, reflection, scattering or excitation-emission element properties/characteristics; 2. Electrical: exposure to an applied electric field. For instance, a direct current or an alternating current may induce changes in (i) the inherent electrical structure of components (e.g., molecules) of the optically readable security element, (ii) the electrical interactions of one or more components (e.g., molecular species of the molecules) or (iii) the physical configuration of the components (e.g., molecules), all impacting the optical refraction, reflection, scattering or excitation-emission element properties/characteristics; 3. Magnetic: as per (2) above but with applied magnetic field; 4. Temperature: for example, temperature-induced (i) chemical transformations of the components (e.g., molecular species) or (ii) interactions between the component (e.g., molecular species). Temperature changes may be positive (e.g., raising a temperature of the optically readable security element above ambient temperature) or negative (e.g., lowering the temperature of the optically readable security element below ambient temperature). Changes in temperature may cause aggregation, polymerisation, conformational change, freezing, a phase change, degradation or break down. Again, the changes impact the optical refraction, reflection, scattering or excitation-emission element properties/characteristics; 5. Mechanical: for example, stretching, bending or compression of the optically readable security element (e.g., via stress or strain) may induce conformational (e.g., position, position relative to other components, orientation or orientation relative to other components) changes of the components (e.g., molecular species), impacting the optical refraction, reflection, scattering or excitation-emission element properties/characteristics; 6. Chemical: (i) external chemical environment such as spraying or immersion in fluid or (ii) direct interaction with introduced chemical species, impacting the optical refraction, reflection, scattering or excitation-emission element properties/characteristics.

In general, the stimulus 22 may impact (e.g., chemically or mechanically) one or more components of the optically readable security element 20, affecting the optical refraction, reflection, scattering or excitation-emission element properties/characteristics (i.e., impact the reading S2 of the optically readable security element 20). The impact could be due to chemical or mechanical (including spatial) changes in the components or between components.

The method may comprise returning the optically readable security element 20 to the first state 20a from the second state 20b. This returning may comprise applying a further stimulus 24 or removing (e.g., withdrawing, stopping, or pausing) the (first) stimulus 22.

Advantageously, returning the optically readable security element 20 to the first state 20a means that, if, for instance, the optically readable security element 20 has been switched to the second state 20b in which the optically readable security element 20 is unreadable (e.g., because it is thought that the first identity provided by the first state has become known, but it transpires that it is not the case that the first identity has become known), the optically readable security element 20 can be returned to a secure state in which it is readable. The further stimulus 24 may be different to the (first) stimulus (e.g., in magnitude, speed or type). As with related examples, this feature of the invention may also allow a temporal control of when the identity is readable or extractable, for example allowing the identity to be read, or not, at desired times.

In the case of the (first) stimulus 22 being optical (see (1) above), applying the further stimulus 24 may comprise exposing the optically readable security element 20 to a different frequency of light compared with the (first) stimulus 22. In the case of the (first) stimulus 22 being electrical or magnetic (see (2) and (3) above), applying the further stimulus 24 may comprise modifying polarity or magnitude of the electric or magnetic field/electric current. In the case of the (first) stimulus 22 being temperature (see (4) above), applying the further stimulus 24 may comprise restoring an original temperature of the optically readable security element 20. In the case of the (first) stimulus 22 being chemical (see (6) above), applying the further stimulus 24 may comprise, for example, drying or wetting the optically readable security element 20 or additional chemical processing.

The method may comprise returning the optically readable security element 20 to the first state 20a from the second state 20b after a preset time or allowing the optically readable security element 20 to return to the first state 20a from the second state 20b after the preset time. In other words, the method may comprise actively driving (e.g., using the further stimulus 24 described above) the optically readable security element 20 back to the first state 20a after a preset time or passively letting the optically readable security element 20 return to the first state 20a. In the latter case, examples include allowing the optically readable security element 20 to return to ambient temperature after having heated it. Similarly, in the case of the (first) stimulus 22 being optical, passive return of the optically readable security element 20 to the first state 20a may result from exposure to natural/ambient light (i.e., an initial or default lighting condition). Advantageously, compared with driving the optically readable security element 20 back to the first state 20a after a preset time, passively allowing the optically readable security element 20 to return to the first state 20a is more energy efficient. Both methods of returning the optically readable security element 20 to the first state 20a after a preset time are advantageous, because, for example, if the first identity is provided by the first state 20a and the second state 20b does not provide an identity, after the first identity has been extracted it is no longer possible to extract the first identity until after the preset time. Such time-limits on extracting an identity from the optically readable security element 20 may hinder or frustrate attempts at spoofing, for instance.

Relatedly, switching S1 from the first state may be permanent and/or the second state may be substantially stable over time. For example, once switching S1 from the first state has taken place, it may never be possible for the optically readable security element 20 to be in the first state 20a, and for example to provide any identity that was initially associated with that state 20a. Advantageously, therefore, reading S2 of the optically readable security element 20 in the first state (e.g., extracting the first identity) may be a one-off event, meaning that, following a legitimate reading and switching S1, further readings (including, for example, spoofing attempts) are not possible.

Advantageously, to facilitate a one-off reading of the optically readable security element in a given state, for example, the stimulus 22 that causes switching S1 of the optically readable security element 20 from the first state 20a to the second state 20b may be initiated (e.g., applied or triggered) by the image capturing device 10 (e.g., by sending a signal to the optically readable security element 20 or a control or stimulus device connected or proximal thereto). That is, after reading S2 by the image capturing device has taken place, the image capturing device 10 may (e.g., automatically) apply the stimulus 22 to switch the optically readable security element 20 to a state with no identity. In another example, the image capturing device 10 may apply the stimulus 22 before the reading S2 to switch the optically readable security element 20 to a desired state (e.g., to a readable state). In effect, the image capturing device 10 may apply a stimulus to "lock" the optically readable security element 20 after reading S2 or to "unlock" the optically readable security element 20 before reading S2.

In another example, the stimulus may be applied or triggered more remotely. A user or administrator could selectively switch one or more optically readable security elements 20 remotely (e.g., via a control or stimulus device connected or proximal to the optically readable security element 20), for example, changing the related identities or turning on/off the identities. This functionality could be to improve security and change or refresh the identities. Alternatively, in another example, this functionality could allow for the identities to be completely enabled or disabled after a period of time (e.g., across a batch or suite of time-sensitive products or related services).

The method may comprise determining a time taken for the optically readable security element 20 to switch from the first state 20a to the second state 20b and verifying the optically readable security element 20 as authentic based on the time taken. The time taken may be indicative of materials used to make the optically readable security element 20, or the environment in which the optically readable security element 20 is or was located (e.g., ambient conditions such as humidity and temperature, chemical environment including immersion in water, or local electric or magnetic fields), each of which may be associated with authenticity of the optically readable security element 20. In general, "environment" may refer to any factor that might influence the switching speed of molecules, and could be ambient (e.g. a passive condition), or the or a stimulus described elsewhere.

For example, the method may comprise retrieving a known time taken for the optically readable security element 20 to switch, comparing the determined time taken with the known time taken and verifying the optically readable security element 20 as authentic only if the determined time is within a preset time range of the known time.

Advantageously, use of a preset time range avoids false negatives. Compared with other methods of authentication of security elements, this method of authentication is especially powerful, because an external observer cannot readily discern the property of the security element relevant to the authentication step, meaning that spoofing is more difficult, and providing an additional hurdle to nefarious activity.

The known time taken may be retrieved from a data store in electronic communication with the image capturing device 10. For example, the known time taken may be stored on the image capturing device 10, an external device or in an engineered component of the optically readable security element (see below description of the optically readable security element), for instance.

The optically readable security element 20 may comprise a hologram, bar code, QR code or similar engineered component, encoding the first and/or second identity. Preferably, the optically readable security element 20 comprises a unique (e.g., randomised) component (e.g., a random deterministic feature), encoding the first and/or second identity. The randomised component encoding the identity, compared with the engineered component encoding the identity, advantageously, engenders a more robust barrier to fraudulent reading of the optically readable security element 20.

In a related example, the engineered component may include information related to the first state 20a or the second state 20b, for example an identity that is expected from a switched-to second state 20b or instructions of how to switch the states 20a, 20b (e.g., what stimulus 22 to apply).

More preferably, the optically readable security element 20 comprises at least one optical component (in this case, an emitter) arranged to be read via emission radiation emitted therefrom. Relatedly, the at least one optical emitter may be arranged to be excited by excitation radiation. The one or more emitters may serve as the component that provides or serves as the unique first and/or second identity. Advantageously, the optically readable security element 20 being read via emission emitted therefrom provides a more robust barrier to fraudulent reading, more readily preventing spoofing or copying by, for instance, simply replicating (e.g., by printing) a bar code, QR code or similar. This advantage is particularly true when one or more (e.g., hundreds, thousands or millions or more) of emitters are distributed randomly. For instance, this effect may be achieved using quantum dots, flakes of 2D materials, (e.g., small) molecules, atomic defects or vacancies, plasmonic structures or similar. In relation to the concept of switching, this use of excitation-emission relationships may be especially powerful, because such excitation-emission relationships are typically sensitive to changes. Therefore, switching S1 is easier to implement and detect or read. For example, the stimuli discussed above may more easily impact excitation-emission relationships or be detected/read by changes in such relationships, than, for instance, impacting and reading changes in spatial separation of optical components by heating or bending of the optically readable element. In other words, switching S1 the optically readable security element 20 via, or resulting in, changes in excitation-emission relationships may be more easily to implemented and/or detect (e.g., read) than changes in reflection, scattering, reflection, etc. The image capturing device 10 may be a terminal device, such as a smartphone. The image capturing device 10 may be configured to emit excitation radiation to excite the at least one optical emitter (e.g., from an electromagnetic radiation source, such as a flash or LED). By being configured to emit excitation radiation, the image capturing device 10, advantageously, facilitates the aforementioned robust security. Further, emitting the excitation radiation from the image capturing device 10, advantageously, allows convenient control of excitation of the at least one optical emitter.

In summary, the present disclosure has described a method that mitigates against the risk to security provided by the optically readable security element in the event that its identity becomes known and generally improves security provided by an optically readable security element by exploiting its switching capability. The described approach also generally improves the functionality provided by new, or perhaps even existing, optically readable security elements. For example, the present invention may be implemented using new (i.e., specifically designed and constructed) optically readable security elements. However, in some circumstances, the above concepts may be applicable to existing security elements. For example, existing optically readable security elements can be made to switch, as discussed above, yet nobody has yet realised or contemplated harnessing this functionality and the associated benefits.

Although preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention, as set out herein are also applicable to all other aspects or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each aspect or exemplary embodiment of the invention as interchangeable and combinable between different aspects and exemplary embodiments.

Claims (15)

1. CLAIMS1. A method of controlling a switchable optically readable security element, the method comprising: switching the optically readable security element from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element.
2. 2. The method of claim 1, wherein: in the first state, the optically readable security element provides the first identity; and in the second state, the optically readable security element provides a second identity.
3. 3. The method of claim 1, wherein: in one of the first state and second state, the optically readable security element provides the first identity; and in the other of the first state and second state, the optically readable security element provides no identity and/or is unreadable.
4. The method of any preceding claim, further comprising: switching the optically readable security element from the first state to the second state in response to a stimulus applied to the optically readable security element.
5. 5. The method of any preceding claim, further comprising: returning the optically readable security element to the first state from the second state in response to a further stimulus or, when dependent on claim 4, removal of the stimulus, optionally, wherein the further stimulus is different to the stimulus.
6. 6. The method of any preceding claim, further comprising: returning the optically readable security element to the first state from the second state after a preset time; or allowing the optically readable security element to return to the first state from the second state after the preset time.
7. 7. The method of any of claims 1 to 4, wherein: the switch from the first state is permanent; and/or wherein the second state is substantially stable over time.
8. 8. The method of any preceding claim, wherein a or the stimulus that causes switching of the optically readable security element from the first state to the second state comprises at least one of: electromagnetic radiation, an electric field, a magnetic field, 15 a temperature change, a mechanical change and a chemical change.
9. 9. The method of any preceding claim, wherein a or the stimulus that causes switching of the optically readable security element from the first state to the second state is initiated by the image capturing device.
10. 10. The method of any preceding claim, wherein the optically readable security element comprises one or more optical emitters arranged to be excited by excitation radiation to cause emission therefrom.
11. 11. The optically readable security element of claim 10, wherein the excitation radiation is emitted from the image capturing device.
12. 12. The method of any preceding claim, further comprising: determining a time taken for the optically readable security element to switch from the first state to the second state; and verifying the optically readable security element as authentic based on the time taken.
13. 13. The method of claim 12, wherein verifying the optically readable security element 5 as authentic comprises comparing the time taken to a time range, and the method further comprises: only verifying the optically readable security element as authentic if the time taken is within the time range.
14. 14. A switchable optically readable security element, wherein: the optically readable security element is arranged to be switched from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element.
15. 15. A system, comprising: a switchable optically readable security element, wherein the optically readable security element is arranged to be switched from a first state to a second state, such that reading of the optically readable security element, using an image capturing device, may be undertaken in the first state or the second state to extract a first identity from the optically readable security element; and the image capturing device, optionally, wherein a stimulus that causes switching of the optically readable security element from the first state to the second state the stimulus is initiated by the image capturing device.