Method for continuously controlling access to a resource and associated devices
Patent Information
- Application Number
- EP2023786583
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-12
- Filing Date
- 2023-10-11
- Publication Date
- 2025-08-20
AI Technical Summary
Existing access control methods, such as fingerprint authentication, are vulnerable to stealthy detection and forced access, necessitating a more secure yet easy-to-implement solution for continuous authentication.
A method utilizing brain activity biomarkers acquired through electroencephalography sensors for initial authentication and continuous validation, including criteria checks for signal quality and mental state, to ensure authorized access and prevent unauthorized access.
Provides high-security continuous authentication that is difficult to bypass, as brain signals are unique and cannot be detected or generated artificially, ensuring only authorized individuals maintain access while reducing cognitive workload and preventing forced access.
Smart Images
Figure 1.1
Abstract
Description
[0001] Method for continuously controlling access to a resource and associated devices
[0002] The present invention relates to a method for continuously authenticating access to a resource. It also relates to an authentication system, a computer program product and a readable information medium involved in the implementation of such an authentication method.
[0003] In the context of a site or equipment with controlled access, it is necessary to be able to ensure as securely as possible that the individual requesting entry to the site or use of the equipment is indeed an individual authorized to carry out this action.
[0004] To do this, it is known to grant access by controlling a biometric characteristic such as a fingerprint. It is necessary and sufficient for the individual requesting access to place his finger on a fingerprint acquisition sensor and for the access control device to verify that this fingerprint matches the fingerprint of an authorized personnel.
[0005] However, malicious individuals can surreptitiously detect fingerprints or force authorized personnel to place their finger on the sensor to gain access to the site or equipment.
[0006] There is therefore a need for a method of controlling access to a resource that is more secure while remaining easy to implement.
[0007] For this purpose, the description describes a method for continuously controlling access to a resource, the method comprising:
[0008] - an initial authentication phase, the initial phase comprising a step of:
[0009] - acquisition of a signal relating to the activity of at least one region of the brain of an individual requesting access to the resource, to obtain an acquired signal, the acquisition step being implemented by a device (16) for acquiring brain activity,
[0010] - extraction of the acquired signal from a predefined biomarker of the individual's identity, to obtain an extracted biomarker,
[0011] - comparison between the extracted biomarker and at least one authentication biomarker, the authentication biomarkers being the biomarkers of at least one individual having authorization to access the resource, to obtain a comparison result,
[0012] - provision of access when the comparison result corresponds to an authentication of the individual requesting access as an individual having authorization to access the resource, - a phase of checking the validity of the initial authentication of the individual requesting access, the control phase comprising a step of:
[0013] - measurement of a signal by the acquisition device, to obtain a measured signal,
[0014] - application of at least one criterion to the measured signal to determine whether each criterion is met or not, each criterion being different from the comparison made during the initial phase,
[0015] - implementation of a series of predefined actions, the series of actions including:
[0016] - when each criterion is met, maintaining access and re-implementing the steps of the control phase, and
[0017] - when at least one criterion is not met, stopping access to the resource.
[0018] According to particular embodiments, the continuous control method has one or more of the following characteristics, taken in isolation or in all technically possible combinations:
[0019] - a criterion used at the application stage is a criterion of capacity of the acquisition device to acquire said signal relating to the activity of at least one region of the brain of the individual requesting access to the resource.
[0020] - the acquisition device is an electroencephalograph comprising electroencephalography sensors and in which:
[0021] - during the measurement step, the measured signal is a signal relating to the activity of at least one region of the brain of the individual requesting access to the resource, and
[0022] - during the application step, the capacity criterion corresponds to a comparison between the quality value of the measured signal and a predetermined quality threshold.
[0023] - the acquisition device is an electroencephalograph comprising electroencephalography sensors and in which:
[0024] - during the measurement step, the measured signal is a signal relating to the activity of at least one region of the brain of the individual requesting access to the resource, and
[0025] - during the application step, the capacity criterion corresponds to a comparison between the amplitude of the measured signal and a predetermined amplitude threshold for a plurality of predefined frequencies.
[0026] - a criterion used in the application step is a mental state criterion of the individual requesting access to the resource to access the resource. - during the measurement step, the measured signal is a signal relating to the activity of the at least one brain region of the individual requesting access to the resource, and during the application step, biomarkers are extracted from the measured signal and the mental state criterion corresponds to a comparison between the biomarkers extracted from the individual requesting access to the resource and threshold values.
[0027] - the initial phase also includes a step of testing the individual's alertness by measuring the brain's response to predefined stimuli, to determine whether the individual requesting access is actually present, and, during the provision step, access is only provided if the individual requesting access is determined to be present.
[0028] The description also describes a system for continuously monitoring access to a resource, the monitoring system comprising:
[0029] - a device for acquiring brain activity, the acquisition device being suitable for:
[0030] - acquire, during an initial authentication phase, a signal relating to the activity of at least one region of the brain of an individual requesting access to the resource, to obtain an acquired signal,
[0031] - measure a signal, during a phase of checking the validity of the initial authentication of the individual requesting access, to obtain a measured signal,
[0032] - a controller specific to:
[0033] - during the initial authentication phase:
[0034] - extract from the acquired signal a predefined biomarker of the individual's identity, to obtain an extracted biomarker,
[0035] - comparing the extracted biomarker and at least one authentication biomarker, the authentication biomarkers being the biomarkers of at least one individual having authorization to access the resource, to obtain a comparison result,
[0036] - provide access when the comparison result corresponds to an authentication of the individual requesting access as an individual having authorization to access the resource,
[0037] - during the control phase:
[0038] - apply at least one criterion to the measured signal to determine whether each criterion is met or not, each criterion being different from the comparison made during the initial phase, - implement a series of predefined actions, the series of actions including:
[0039] - when each criterion is met, maintaining access and re-implementing the steps of the control phase, and
[0040] - when at least one criterion is not met, stopping access to the resource.
[0041] The description also relates to a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of extraction, comparison, provision, application and implementation according to a control method as previously described.
[0042] The description also describes a computer-readable medium, on which the computer program as previously described is recorded.
[0043] In this description, the expression "suitable for" means indifferently "adapted for", "adapted to" or "configured for".
[0044] Characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings, in which:
[0045] - Figure 1 is a schematic representation of an example of a system for continuously monitoring access to a resource by an individual, and
[0046] - Figure 2 is a schematic representation of part of the control system.
[0047] A system 10 for continuously monitoring access to a resource 12 is shown in FIG. 1.
[0048] The control system 10 is capable of controlling access to the resource 12 by an individual 14.
[0049] The control system 10 is thus able to verify that the individual 14 has authorization to access the resource 12.
[0050] Such monitoring is carried out here on a continuous basis.
[0051] By "continuous" in this context, it is meant that access is not permanent. Access is checked multiple times and preferably constantly.
[0052] For example, after an initial access check, real-time sensor disconnection detection is implemented to detect any variation (change of identity or movement of the authenticated individual). In such a case, the check is considered continuous.
[0053] Resource 12 is any type of restricted-access item. For example, a computer, files, machine, or room may be subject to controlled access, meaning that only certain individuals have access permission. Other individuals are not allowed to access these controlled-access items.
[0054] According to the example of Figure 1, resource 12 is a computer.
[0055] The control system 10 comprises a device 16 for acquiring brain activity, a controller 18 and a human-machine interface 20.
[0056] The acquisition device 16 is a device for measuring brain activity, that is to say the activity of at least one region (or zone) of the brain.
[0057] Such an acquisition device 16 may be an electroencephalograph or a functional imaging device, such as an ultrasound imager or an imager suitable for implementing a magnetic resonance imaging technique (this technique being more often designated by the corresponding acronym MRI).
[0058] In the following and in accordance with the example of figure 1, it is assumed without loss of generality that the acquisition device 16 is an electroencephalograph 16.
[0059] The electroencephalograph 16 is a device for obtaining electroencephalography signals. Such signals are often referred to as EEG signals by reference to the corresponding abbreviation.
[0060] As seen in Figure 1, the electroencephalograph 16 comprises a headset 22 and electroencephalography sensors 24.
[0061] The helmet 22 is intended to be positioned on the head of the individual 14.
[0062] The sensors 24 are suitable for measuring the electrical activity of a region of the brain of the individual 14.
[0063] The sensors 24 are, for example, electrodes.
[0064] The sensors 24 are positioned at several different locations on the head of the individual 14.
[0065] The controller 18 is a physical entity, such as a computer.
[0066] According to a first example, the controller 18 comprises a processor 26, a memory 28 and an information medium reader 30.
[0067] The controller 18 is intended to interact with a computer program product comprising an information medium readable by the reader 30 of the controller 18.
[0068] The readable information carrier of the computer program product is, for example, a medium suitable for storing electronic instructions and capable of being coupled to a bus of a computer system.
[0069] For example, the readable information medium is a USB key, a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, a ROM memory, a RAM memory, any type of non-volatile memory (for example, EPROM, EEPROM, FLASH, NVRAM), a magnetic card or an optical card.
[0070] A computer program comprising program instructions is stored on the readable information carrier.
[0071] The computer program is loadable onto the processor 26 and is adapted to cause the implementation of steps which will be described in the remainder of the description.
[0072] In a second example, the controller is of the hardware type (literally translated into French as "material"), such as a programmable logic circuit (abbreviated as FPGA, which means "Field Programmable Gate Array" in English), or a dedicated integrated circuit, such as an ASIC (from the English "Application-Specific Integrated Circuit").
[0073] In the case of Figure 1, the controller 18 is integrated into the headset 22.
[0074] Alternatively, the controller 18 is remote from the headset 22 and communicates with the headset 22 via a wired connection or a wireless connection of the Bluetooth or Wifi type.
[0075] According to the example, the human-machine interface 20 is a screen capable of transmitting visual messages to the individual 14.
[0076] Alternatively or additionally, the human-machine interface 20 comprises a sound reproduction device and the message is an audible signal.
[0077] The human-machine interface 20 is, for example, integrated into a portable device 32 (illustrated in FIG. 1), such as a smartphone 32. For example, an application is installed on the smartphone 32 which allows interaction between the controller 18 and the human-machine interface 20.
[0078] In one example, the controller 18 and the human-machine interface 20 are integrated into a single device, for example, a portable device, such as a smartphone.
[0079] The operation of the control system 10 is now described with reference to an example of implementation of a method for continuously controlling access to the resource 12.
[0080] The control process aims to control the access of individual 14 to resource 12.
[0081] In other words, it is a matter of verifying that the individual 14 requesting access to the resource 12 is an individual benefiting from access authorization.
[0082] The control process seeks to carry out this verification continuously.
[0083] To do this, the process involves two phases: an initial authentication phase and a phase for checking the validity of the initial authentication.
[0084] The initial authentication phase comprises, according to the example described, an acquisition step, an extraction step, a comparison step and a provision step. During the acquisition step, the electroencephalograph 16 records at the scalp a signal relating to the activity of at least one region of the brain of the individual 14 requesting access to the resource.
[0085] The brain activity signal corresponds to the electromagnetic oscillations generated by the human brain.
[0086] All regions of the brain are subject to these oscillations with variations depending on the region considered.
[0087] Also, the regions chosen may vary depending on the nature of the control to be carried out.
[0088] For example, one could choose to place the electrodes in the frontal region of the head to detect the activity of the frontal cortex.
[0089] At the end of the acquisition step, the control system 10 thus has an acquired signal.
[0090] The controller 18 then extracts, during the extraction step, at least one predefined biomarker of the identity of the individual.
[0091] By definition, a predefined biomarker of the individual's identity is a distinctive characteristic of the acquired signal, which here is an electroencephalogram.
[0092] An example of a predefined biomarker is a spectral characteristic such as the representative rhythm of a brain wave, such as the alpha rhythm or the beta rhythm.
[0093] Alpha rhythm is a rhythm characterizing oscillatory brain electrical activity in a frequency band typically ranging from 7.5 Hertz (Hz) to 14 Hz.
[0094] Similarly, the beta rhythm characterizes oscillatory brain electrical activity in a frequency band typically ranging from frequencies above 15 Hz to generally below 30 Hz.
[0095] The ratio between different rhythms, the central frequency of each rhythm, the power of alpha waves, the power of beta waves, the spectral power over a specific frequency band, the value of the amplitude of electrical activity at several frequencies are other examples of predefined biomarkers of the individual's identity.
[0096] A biomarker is therefore a brain fingerprint specific to an individual. Its uniqueness guarantees proper authentication of the individual.
[0097] The biomarkers are predefined in the sense that their determination must allow the comparison step to be carried out.
[0098] The controller 18 thus has an extracted biomarker, that is to say a value for the predefined biomarker for the individual 14 requesting access.
[0099] During the comparison step, the controller 18 then performs a comparison between the extracted biomarker and at least one authentication biomarker. The authentication biomarkers are the biomarkers of at least one individual having authorization to access the resource. These authentication biomarkers are stored in a memory 28 of the controller 18.
[0100] The comparison here is to ensure that the authentication biomarker and the extracted biomarker are identical within a margin.
[0101] The margin generally corresponds to the measurement error in the determination of the extracted biomarker.
[0102] According to a variant, the individual 14 can declare his identity prior to the comparison step and the comparison is carried out only with the authentication biomarker corresponding to the declared identity.
[0103] At the end of the comparison step, the controller 18 thus has a result of the comparison.
[0104] Controller 18 then provides access or not to the resource.
[0105] This supply is made based on the result of the comparison
[0106] The controller 18 provides access to the resource only when the comparison result corresponds to an authentication of the individual 14 requesting access as an individual having authorization to access the resource.
[0107] At each of the aforementioned steps, the human-machine interface 20 can display indications towards the individual 14 seeking to identify himself.
[0108] For example, the human-machine interface 20 may indicate that the comparison is in progress or whether the authentication was successful or not.
[0109] The control system 10 then implements the phase of checking the validity of the initial authentication.
[0110] This involves verifying that it is always the same individual 14 who uses the resource.
[0111] According to the example described, the control phase includes a measurement step, an application step and an implementation step.
[0112] In the measurement step, the electroencephalograph 16 measures a signal.
[0113] In the application step, the controller 18 applies a criterion to the measured signal to determine whether or not the criterion is met.
[0114] According to a first example, the criterion is a criterion of capacity of the electroencephalograph 16 to acquire said signal relating to the activity of at least one region of the brain of the individual 14 requesting access to the resource 12.
[0115] In such an example, the measured signal is a signal representative of the activity of at least one region of the brain of the individual 14 requesting access.
[0116] The controller 18 then evaluates the capacity criterion by comparing the quality of the acquired signal with a predetermined quality threshold. Typically, if the measured signal quality falls below a predetermined value, this is a sign that the contact between the sensors 24 and the head of the individual 14 is very poor.
[0117] Signal quality is, for example, assessed by determining the variation in the signal-to-noise ratio.
[0118] Alternatively or additionally, the controller 18 may use as a capacity criterion a comparison between the amplitude of the signal and a predetermined amplitude threshold for a plurality of predefined frequencies.
[0119] Typically, if at all predefined frequencies the amplitude of the measured signal is too high, this also means that the contact between the sensors 24 and the head of the individual 14 is very poor.
[0120] According to a second example, the criterion is a mental state criterion of individual 14 requesting access to resource 12.
[0121] Typically, an individual does not have the mental capacity to access a resource 12 if they are stressed, lack vigilance, or show signs of fatigue that alter their mental state. This can come either from the individual themselves or from changes in the environment. Mental state is therefore a criterion here assessing whether the individual 14 is in the same conditions as when the initial authentication phase was implemented.
[0122] To determine this mental state of the individual 14, the measured signal is, for example, a signal relating to the activity of at least one region of the brain of the individual requesting access to the resource 12.
[0123] The measured signal is thus the same signal as the acquired signal but at a later time.
[0124] Alternatively, if relevant, the measured signal could be a signal from other regions.
[0125] In the application step, the controller 18 extracts mental state biomarkers from the measured signal and the controller 18 compares the extracted biomarkers with threshold values.
[0126] The threshold values are predefined and determined beforehand and are stored in the memory 28 of the controller 18.
[0127] According to a third example, the criterion to be respected is a set of at least two sub-criteria.
[0128] According to a particular case of the third example, the two sub-criteria are the criterion of capacity of the electroencephalogram 16 and the criterion of mental state of the individual 14.
[0129] At the end of the application step, the control system 10 thus knows whether the chosen criterion is met or not. In each case, the criterion is different from the authentication requested during the initial phase. This makes verification simpler than obtaining access.
[0130] The control system 10 then implements a series of predefined actions which depends on the outcome of the application step.
[0131] In other words, when the criterion is met, the control system 10 implements a first series of actions whereas, when the criterion is not met, the control system 10 implements a second series of actions, the first series of actions being very different from the second series of actions.
[0132] The first set of actions involves maintaining access and re-implementing the steps of the control phase.
[0133] The time gap with the new implementation is preferably as small as possible, typically one second.
[0134] According to the described example, the second sequence of actions involves stopping access to the resource.
[0135] In such a case, individual 14 must go through the steps of the initial phase again if he wants to have access to resource 12 again.
[0136] In another example, the second sequence of actions also includes a warning to individual 14 that the criterion is not met.
[0137] Typically, the human-machine interface 20 displays a message indicating that the control system 10 will prohibit access within a few seconds if the contact between the sensors 24 and the head of the individual 14 is not improved in the meantime.
[0138] The control method just described has the advantage of a certain universality insofar as every living person generates unique brain signals.
[0139] The level of security provided by the control process is, moreover, high.
[0140] This is because electroencephalography data cannot be surreptitiously detected and cannot be artificially generated.
[0141] This limits the possibility of identity theft, unlike, for example, password-based or fingerprint-based authentication. Theft of electroencephalography data is not possible.
[0142] Furthermore, brain signals cannot be extracted without the cooperation of the individual wishing to access the resource 12.
[0143] This prevents individual 14 from being able to access resource 12 under threat, and thus a forced extraction of access.
[0144] In addition, the method makes it possible to continuously ensure that the individual 14 accessing the resource 12 is always the same person who authenticated previously. This guarantee is obtained with a good level of security and is easier to implement than a periodic verification of identity by repeating the steps of the initial phase.
[0145] Indeed, the continuous extraction of the brain imprint of the individual 14 to be identified requires the execution of a task, increases the workload and thus generates stress in the individual and therefore reduces his productivity.
[0146] Furthermore, the method does not involve the explicit execution of a task following the first authentication, so the method is considered silent.
[0147] The method thus makes it possible to carry out continuous authentication of the identity of the individual 14 under operational conditions while avoiding a cognitive impact on the workload of the individual 14 since the complete authentication is only carried out once.
[0148] As a result, the process remains quick to implement since only the initial authentication takes more than a few seconds (typically 3 seconds), the rest of the actions carried out being completely transparent to the individual 14 requesting access.
[0149] The method further allows for the determination of potentially dangerous alterations, such as the exertion of a threat on the individual 14 or the deterioration of the mental state of the individual 14, in a reliable and silent manner.
[0150] If necessary, the security level of the control process can be reinforced.
[0151] In particular, an embodiment may be envisaged in which the method further comprises a procedure known as liveness detection, more commonly called “liveness detection” with reference to the corresponding English term.
[0152] For this, according to one example, the initial phase also includes a step of testing the liveliness of the individual 14 by measuring the cerebral response to predefined excitations, to determine whether the individual 14 requesting access is awake.
[0153] The predefined excitations are random and can correspond to any type of excitation. For example, it can be visual or audio excitation.
[0154] Such excitations are often referred to as "pings."
[0155] In the presence of such stimuli, the individual's brain response 14 exhibits reproducible patterns. The term "time-locked" (in reference to the corresponding English term which literally translates as "stuck in time") is often used to describe such a brain reaction.
[0156] The absence of these reproducible patterns in response to stimuli is evidence of a lack of alertness in the individual 14. For example, this may be a sign of the use of a previously recorded or synthetically generated signal.
[0157] When liveness is tested, during the provision step, access is only provided if the individual 14 requesting access is determined to be actually physically present, i.e. present in front of the control system 10, in particular by being equipped with the headset 22.
[0158] Access to the resource 12 is therefore only given if, on the one hand, the individual 14 is identified as having authorization to access the resource 12 and, on the other hand, the individual 14 requesting access is determined to be present in front of the control system 10.
[0159] The use of this double criterion during the initial authentication phase reinforces the security provided by the implementation of the continuous control process.
[0160] Those skilled in the art will understand that the invention is not limited to the examples described in the description and that the embodiments described above are likely to be combined when such a combination is technically possible.
Claims
CLAIMS 1. Method for continuously controlling access to a resource (12), the method comprising: - an initial authentication phase, the initial phase comprising a step of: - acquisition of a signal relating to the activity of at least one region of the brain of an individual (14) requesting access to the resource (12), to obtain an acquired signal, the acquisition step being implemented by a device (16) for acquiring brain activity, - extraction of the acquired signal from a predefined biomarker of the individual's identity, to obtain an extracted biomarker, - comparison between the extracted biomarker and at least one authentication biomarker, the authentication biomarkers being the biomarkers of at least one individual having authorization to access the resource, to obtain a comparison result, - providing access when the comparison result corresponds to an authentication of the individual (14) requesting access as an individual having authorization to access the resource (12), - a phase of checking the validity of the initial authentication of the individual (14) requesting access, the control phase comprising a step of: - measurement of a signal by the acquisition device (16), to obtain a measured signal, - application of at least one criterion to the measured signal to determine whether each criterion is met or not, each criterion being different from the comparison made during the initial phase, - implementation of a series of predefined actions, the series of actions including: - when each criterion is met, maintaining access and re-implementing the steps of the control phase, and - when at least one criterion is not met, stopping access to the resource (12).
2. Continuous monitoring method according to claim 1, in which a criterion used in the application step is a criterion of capacity of the acquisition device (16) to acquire said signal relating to the activity of at least one region of the brain of the individual (14) requesting access to the resource (12).
3. Continuous monitoring method according to claim 2, in which the acquisition device (16) is an electroencephalograph comprising electroencephalography sensors (24) and in which: - during the measurement step, the measured signal is a signal relating to the activity of at least one region of the individual's brain (14) requesting access to the resource, and - during the application step, the capacity criterion corresponds to a comparison between the quality value of the measured signal and a predetermined quality threshold.
4. Continuous monitoring method according to claim 2, in which: - during the measurement step, the measured signal is a signal relating to the activity of at least one region of the individual's brain (14) requesting access to the resource, and - during the application step, the capacity criterion corresponds to a comparison between the amplitude of the measured signal and a predetermined amplitude threshold for a plurality of predefined frequencies.
5. Continuous monitoring method according to any one of claims 1 to 4, wherein a criterion used in the application step is a mental state criterion of the individual (14) requesting access to the resource to access the resource (12).
6. Continuous monitoring method according to claim 5, in which: - during the measurement step, the measured signal is a signal relating to the activity of at least one region of the individual's brain (14) requesting access to the resource, and - during the application step, biomarkers are extracted from the measured signal and the mental state criterion corresponds to a comparison between the biomarkers extracted from the individual (14) requesting access to the resource (12) and threshold values.
7. Continuous monitoring method according to any one of claims 1 to 6, in which the initial phase also comprises a step of testing the liveliness of the individual (14) by measuring the cerebral response to predefined excitations, to determine whether the individual (14) requesting access is actually present, and, during the provision step, access is only provided if the individual (14) requesting access is determined to be present.
8. System (10) for continuously monitoring access to a resource (12), the monitoring system (10) comprising: - a device (16) for acquiring brain activity, the acquisition device (16) being suitable for: - acquiring, during an initial authentication phase, a signal relating to the activity of at least one region of the brain of an individual (14) requesting access to the resource (12), to obtain an acquired signal, - measure a signal, during a phase of checking the validity of the initial authentication of the individual (14) requesting access, to obtain a measured signal, - a controller specific to: - during the initial authentication phase: - extract from the acquired signal a predefined biomarker of the individual's identity, to obtain an extracted biomarker, - comparing the extracted biomarker and at least one authentication biomarker, the authentication biomarkers being the biomarkers of at least one individual having authorization to access the resource (12), to obtain a comparison result, - provide access when the comparison result corresponds to an authentication of the individual requesting access as an individual having authorization to access the resource, - during the control phase: - apply at least one criterion to the measured signal to determine whether each criterion is met or not, each criterion being different from the comparison made during the initial phase, - implement a series of predefined actions, the series of actions including: - when each criterion is met, maintaining access and re-implementing the steps of the control phase, and - when at least one criterion is not met, stopping access to the resource (12).
9. Computer program product computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of extracting, comparing, providing, applying and implementing a continuous monitoring method according to any one of claims 1 to 8.
10. Computer-readable medium on which the computer program according to claim 9 is recorded.