Patent Publication Number: US-2021195413-A1

Title: Two factor authentication using molecular communication - a system and method

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The instant application is a continuation in part of U.S. application Ser. No. 16/720,908 filed on 19 Dec. 2019. The pending U.S. application Ser. No. 16/720,908 is hereby incorporated by reference in its entireties for all of its teachings. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to implanted electronic medical devices (IEMDs), and more specifically, to securing the wireless communication link with an implanted electronic medical device. In addition, the invention relates to using molecular communication in the human body. 
     BACKGORUND 
     Implanted electronic medical devices (IEMDs) are electronic devices that are installed inside the body for medical purposes and used for treatment or diagnostic purposes. They are designed to stay in the body for long periods of times. Heart pacemakers, insulin pumps, and neurostimulators are some examples of IEMDs. Many IEMDs are equipped with communication and networking functionalities that allow them to provide sophisticated features such as reporting measurements or alarms in real time or changing their settings or configuration without removing them from the body. 
     The use of electromagnetic waves to communicate wirelessly with an IEMD makes them vulnerable to many cyber-attacks. The Department of Homeland Security in the United States characterized three vulnerabilities in pacemakers which allowed an attacker to hijack the wireless link and send commands that could harm patients such as performing a shock that is not needed, send streams of wake-up commands to deplete the battery, or eavesdrop on sensory data sent to external Wireless Programmer and Reader (WPR). Any implanted electronic medical device (IEMD) utilizing electromagnetic waves for wireless functionalities is subject to the same vulnerabilities. There is a need for more secure system and method for operating these devices. 
     SUMMARY 
     This disclosure generally relates to a Two Factor Authentication using Molecular Communication (TFAMoCo) system and method to prevent hacking the wireless link of an IEMD. A two factor authentication system is provided comprising a transmitter which is configured to release signaling molecules in the body in a controlled manner to modulate information, and a receiver such as an IEMD with molecular communication (MC) module for receiving data by measuring the concentration of molecules in the body to infer the encoded information in addition to an electromagnetic module (EM) to make wireless link with WPR, and a WPR used to reprogram, read logged data, or enable or disable the IEMD, and signaling molecules, and a communication channel which is a human body. 
     In another aspect of the invention, a Two Factor Authentication using Molecular Communication (TFAMoCo) method is provided, comprising the steps (a) A Personal Identification Number (PIN)is generated either manually or randomly and input into the molecular communication transmitter, (b) The transmitter is connected to the body, (c) The transmitter sends PIN number using molecules by controlling the amount and release time of signaling molecules (d) The IEMD changes to wake up mode after detecting a change in the concentration of signaling molecules and process the transmitted signal and extract the PIN number, (e) The IEMD enables the EM module, (f) The IEMD requests the PIN number via the wireless link from the WPR, (g) The WPR operator input the same PIN generated in step (a), (h) The IEMD compares the PIN values received through the MC module and the one received from the EM module, (i) If the PIN received from MC module equals PIN received from the EM module, the IEMD moves to step (j) otherwise it moves to step (k), (j) The IEMD keeps EM module active and WPR access is granted to the IEMD resources from the wireless link, (k) The IEMD disables the EM module and returns to sleep mode. 
     Other features will be apparent from the accompanying drawings and from the detailed description that follows. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Example embodiments are illustrated by way of example only and not limitation, with reference to the figures of the accompanying drawings, in which like references indicate similar elements and in which: 
         FIG. 1  is a diagram showing one configuration of a system using Two Factor Authentication with Molecular Communication (TFAMoCo) according to an embodiment of the present invention. 
         FIG. 2  is a process flow chart illustrating steps of TFAMoCo method according to an embodiment of the present invention. 
         FIG. 3  is a process flow chart illustrating steps of an example implementation of transmitting a PIN number using molecular communication signaling used by a transmitter according to an embodiment of the present invention. 
         FIG. 4  is a diagram showing an example of an input signal modulating an example PIN number  1001  according to an embodiment of the present invention. 
         FIG. 5  is a process flow chart illustrating steps of an example implementation of TFAMoCo at an IEMD according to an embodiment of the present invention. 
         FIG. 6  is a diagram showing an example of sampled molecular signal captured by a MC module in an IEMD according to an embodiment of the present invention. 
         FIG. 7  is a diagram showing an example of a recovered input signal at the IEMD according to an embodiment of the present invention. 
     
    
    
     Other features of the present disclosure will be apparent from the detailed description of embodiments that follows. 
     DETAILED DESCRIPTION 
     In this disclosure, we propose a two factor authentication method using molecular communication (TFAMoCo) in conjunction with electromagnetic communication to circumvent the connectivity shortcomings of IEMDs. Molecular communication (MC) uses molecules for conveying information by modulating it using the properties of molecules such as number, type or time of release. The motivation behind using MC in the body mainly lies in the fact that MC links provides privacy and security. The signaling molecules are released in, and confined to, the body fluids which provide high robustness against eavesdropping, particularly when compared to electromagnetic waves. In addition, hijacking the communication link cannot take place without noticeable physical contact with the body which the patient would be aware of in most cases and thus be capable of preventing it. The present invention is described in enabling detail in the following examples, which may represent more than one embodiment of the present invention. 
       FIG. 1  is a diagram showing one configuration of a system using Two Factor Authentication with Molecular Communication (TFAMoCo) according to an embodiment of the present invention. The TFAMoCo system  100  comprises a transmitter or a set of transmitters ( 110 , 120 , 130 ), signaling molecules  102 , an IEMD  140  such as a pacemaker, a wireless programmer and reader (WPR)  150 , a human body  101  as a communication channel. 
     The human body  101  has an IEMD  140  such as a pacemaker in this example but other IEMDs are possible in other embodiments of this invention. The IEMD  140  is implanted to perform specific therapeutic tasks and ideally is equipped with an electromagnetic EM module  142  that has a wireless interface that enables wireless connection  160  with a WPR  150 . The WPR  150  can be used to reprogram, read logged data, enable or disable the IEMD  140  without removing it from the patient. In this invention, we propose adding a new MC module  141  that has a molecular interface  143  that can detect the presence or absence of a specific signaling molecules  102  and has a method and mechanism known in the art to estimate their count or concentration in its vicinity. 
     The signaling molecules  120  can be any substance that can be absorbed, distributed, metabolized, and excreted safely by the human body. In addition, it must be detectable and measurable by the IEMD&#39;s MC module  141 . The transmitters ( 110 , 120 , 130 ) release signaling molecules in the human body to communicate with the IEMD&#39;s MC module  141 . They encode information by controlling the amount and release time of signaling molecules. 
     There are many routes of administering signaling molecules into the body, such as but not limited to, oral, dermal, intravenous, or inhaling. The route of administration determines the transmitter form. For example, in oral administration the transmitter components can be enclosed in a pill shaped container so that they can be taken orally and work from inside the body such as  110  and  120 . Alternatively, the transmitter could be designed to work externally by attaching it to the body from outside such as the transmitter  130 . 
       FIG. 1  ( 120 ) shows an example of a passive multi compartment smart pill that can modulate multiple symbols that can be taken orally. Each compartment may contain a solid or liquid form of signaling molecules or combination of both. The compartments may be made from membranes or materials that has different biodegradability or made from the same material with different thickness so that the dissolution time of one compartment is different than the other. By setting different amounts of signaling molecules and changing the dissolution time of each compartment, the pill can control the amount and release time of signaling molecules to encode different symbols. 
       FIG. 1  ( 110 ) shows an active transmitter in the form of a pill that can be taken orally and work from inside the body. The transmitter may comprise a microcontroller  111 , power source  112 , signaling molecules reservoir  113 , a releasing mechanism  114 , and an aperture  115 . The microcontroller  111  is powered by the power source  112  and is programmed to perform all the functions of a traditional transmitter except that it has a mechanism to control the signaling molecules amount and release time based on the information to be modulated. In this example, the release mechanism could be controlled using a pump  114  that is powered to administer molecules through the aperture  115  and switched off to stop. 
       FIG. 1  ( 130 ) shows an active transmitter that could be placed inside a small box  135  with an infusion set  136  that has a cannula  138 . The cannula  138  can be inserted through the skin into the body and fixed in place with a patch  137  while delivering the signaling molecules to the body. The transmitter may comprise a microcontroller  131 , power source  132 , signaling molecules reservoir  133  and a releasing mechanism  134 . The microcontroller  131  is powered by the power source  132  and is programmed to perform all the functions of a traditional transmitter except that it has a mechanism to control the signaling molecules amount and release time based on the information to be modulated. In this example, the release mechanism could be controlled using a pump  134  that is powered to administer molecules and switched off to stop. 
       FIG. 2  is a process flow chart illustrating steps  200  of TFAMoCo method according to an embodiment of the present invention. Ideally, the IEMD  140  is in sleep mode and its EM module  142  is turned off to prevent hacking the device. However, the molecular communication interface  141  is on and measures the concertation of the signaling molecules  102 . The TFAMoCo method comprises a set of steps to wake up the IEMD  140  and activate its EM module  142  utilizing the IEMD&#39;s MC module  141  for detecting a molecular signal that carries a valid PIN number. The PIN number can be composed of a string of digits, letters, symbols, or combination of them. A PIN can be numeric or alpha-numeric of fixed length. For example, the code  9102  is a 4-digit numeric PIN. At step  201 , a PIN MC  number is generated either manually or randomly and input into the molecular communication transmitter. In the case of an active transmitter, the PIN MC  may be keyed using but not limited to a keypad or any alternative input method known in the art. In the case of a passive transmitter, the PIN MC  may be encoded using combinations of signaling molecules and dissolution time of the compartments holding the signaling molecules. After that, the transmitter is connected to the body. In one embodiment, the connection may be realized suing a transmitter such as the one shown in  FIG. 1  ( 130 ) by connecting the transmitter needle  138  to the body. In another embodiment, the transmitter may be connected by taking it orally such as pill shaped transmitter shown in  FIG. 1  ( 110 , 120 ). At step  202 , the transmitter starts sending PIN MC  number using molecules by controlling the amount and release time of signaling molecules as explained in  FIG. 3 . At step  203 , the IEMD wakes up after detecting the signaling molecules and process the transmitted signal to extract the PIN MC  number. At step  204 , the IEMD enables the EM module  142  and request the PIN number via the wireless link from the WPR  150  at step  205 . At step  206 , the WPR  150  operator input the same PINT MC  generated in step  201  which is denoted as PIN WR  and send it to the EM module  142 . At step  207 , in one embodiment, the EM module  142  forwards PIN WR  to the MC module  141 . At step  208 , the IEMD MC module  141  compares the PIN values received through the MC module (PINT MC ) and the one received from the EM module (PIN WR ). If the PIN MC  equals PIN WR , the IEMD moves to step  209  and keeps EM module active and grant WPR  150  access to the IEMD resources from the wireless link in step  210 . Otherwise, the IEMD moves to step  211  and then disable the EM module at step  212  to prevent an authorized access. 
     In another embodiment, the comparison between PIN MC  equals PIN WR  may be done by software or hardware or both or any other method known in the art. In addition, it may be in any module or part of IEMD known in the art such as but not limited to an IEMD&#39;s microprocessor. 
       FIG. 3  is a process flow chart illustrating steps  300  of an example implementation of transmitting a PIN number using molecular communication signaling used by a transmitter according to an embodiment of the present invention. The user starts the transmitter at step  301 . Then, the user enters a PIN number in the transmitter manually or let the transmitter generate a random pin and start transmission at step  302 . In this example, the PIN is composed of four bits such as  1001  but can be longer or shorter. Then, at step  303 , the transmitter sends a wake up signal by releasing signaling molecules into the body in this example by running a pump for T 1  seconds that will elevate the concentration of the signaling molecules to a level that can be triggered by the MD module in the IEMD. At step  304 , the transmitter stops releasing the signaling molecules for τ 2  seconds in this example by stopping the pump to allow the body to absorb, distribute, metabolize, and excrete the signals molecules such their concentration level stays the same or start to decline. Then, the transmitter uses a modulation scheme such as, but not limited to, the on off keying ( 00 K) to create a molecular signal. The OOK is done by reading a bit at a time at steps  305  and  306 . If the bit is one go to step  309  and inject signaling molecules into the body by running a pump for τ 1  seconds. At step  310 , the transmitter stops injecting signaling molecules, in this example, by means of stopping the pump for τ 2  seconds then moves to step  305 . On the other hand, if the bit is zero at step  307 , the transmitter does not inject signaling molecules to the body, in this example, by keeping the pump off and waits for τ 4  seconds before it proceeds to step  305 . The process continues till all bits are transmitted where the transmitter moves from step  305  to  311  and ends the transmission. The values for τ 1 , τ 2 , τ 3 , and τ 4  are selected based on the ADME process rates so that the receiver can detect molecular signal and infer the sent message. An example of a modulated input signal sent using the OOK is shown in  FIG. 4 . 
       FIG. 4  is a diagram showing an example of an input signal modulating an example PIN number  1001  according to an embodiment of the present invention. In this example, the transmitter is using on off keying where it injects signaling molecules to modulate a one and stop injecting to modulate a zero. 
       FIG. 5  is a process flow chart illustrating steps  500  of an example implementation of TFAMoCo at an IEMD according to an embodiment of the present invention. At step  501 , the operator starts the IEMD. Once the IEMD is started and initialized  501 , it stays on and measures the concentration of the signaling molecules while switching between the sleep and wake up modes. The IEMD enters the sleep mode  502  after starting and measures the concentration of the signaling molecules (C). At step  503 , it checks if C is less than a predefined concentration level C H , it goes to step  504  and sleeps for τ 1  seconds before it returns to step  502  and takes another measurement. However, at step  503 , if C is not less than C H , it assumes that the transmitter is transmitting and moves to step  505  where it changes to wake up mode and measure the signaling molecules concertation. At step  506 , if C is greater than a predefined concentration level C L , it goes to step  507  and waits for τ 2  seconds. Then, it returns to step  505  again and take another measurement of C. Ideally, τ 2  should be much smaller than τ 1  to enable the MC module to measure more frequently and get more measurements. In this example, the measured concentration values are stored to be processed later to infer the information send by the transmitter. At step  506 , if C is not greater than C L , the IEMD assumes that the transmitter has finished transmitting and moves to step  508 . An example of the received sampled signal is shown in  FIG. 6 . 
     At step  508 , the IEMD stops measuring C and moves to step  509 . At step  509 , the IEMD process sampled signal to retrieve PIN sent by the transmitter. At step  510 , the IEMD turns the EM module on and starts pairing with a WPR at step  511 . At step  512 , the IEMD EM module requests the PWR to provide the PIN number the operator transmitted through the MC module. At step  513 , the IEMD compares the value of PIN received from MC module with the value provided by WPR through the EM module. If the WPR provides the correct PIN number, it moves to step  515  where the WPR is authenticated and its access to the IEMD resources is granted. Otherwise, it moves to step  514  and disables the EM module, then, it returns to sleep mode at step  502 . 
       FIG. 6  is a diagram showing an example of sampled molecular signal captured by a MC module in an IEMD according to an embodiment of the present invention. The diagram shows several concentration peaks. The first peak has a very sharp increase in the concentration level due to the first dose injected by the transmitter to signal for the duration of T 1  seconds to trigger the wake-up mode in the IEMD. After that, a constant decrease in concentration takes place as a result of eliminating the signaling molecules from the body while the transmitter stopped injecting molecules for τ 2  seconds. Then, we observe a second peak that results from modulating the first bit where the transmitter keeps injecting molecules for τ 3  seconds to modulate a one. Then, there is a decrease in the concentration for duration τ2+2*τ4 seconds which results from transmitters silence after sending a one and for modulating two consecutive zeros by stopping injecting molecules during this time. Finally, we see a third peak which corresponds to modulating the fourth bit which happens to be one. The concentration continues to decrease slowly over time afterwards because the transmitter is not injecting more molecules and the body continues eliminating the remaining molecules from the body. 
       FIG. 7  is a diagram showing an example of a recovered input signal at the IEMD according to an embodiment of the present invention. The figure shows 3 spikes. The first represents the wake-up signal. During the first bit duration after the wake-up signal, there is a spike. However, there are no spikes for duration the second and third bits. After that, there is a spike during the duration of the fourth bit. The presence and absence of spikes indicates the location where there are ones and zeros in the transmitted signal.