Abstract:
Various embodiments of the invention achieve optimal data security by adding a security layer to data at the point of generation. Some embodiments add a security feature to data that controls or configures a device at a physical interface.

Description:
BACKGROUND 
     A. Technical Field 
     The present invention relates to secure data transmission, and more particularly, to systems, devices, and methods of securing devices that are remotely controlled over a network. 
     B. Background of the Invention 
     A rapidly increasing number of communication systems rely on transferring data over networks in order to remotely control devices, such as sensors and actuators that are connected to cloud-based computing architectures. Often large amounts of data is aggregated and transferred to servers or data centers that monitor incoming data and respond accordingly. For example, a distributed network of smoke detectors and temperature sensors may collect temperature data inside a building and transmit the data to a remotely located server that monitors one or more environmental conditions. The remote server continuously analyzes the data, and based on the results takes some action via one or more interfacing actuators, such as adjusting the temperature setting on an air-conditioning system or activating a sprinkler system in case of detecting a fire. 
     One major concern associated with data communication over networks that facilitate operation of automated equipment with no human interaction or oversight is the exposure to unauthorized or accidental data manipulation. Where data transfer and decision making are practically unsupervised, potential intruders can relatively easily intercept the data stream to carry out attacks on networked devices while remaining entirely undetected. Data interruption or partial data loss can render devices inoperative, as each device typically expects a predetermined sequence of data (e.g., a data protocol) to establish communication and transfer information. Data security is particularly important in certain applications, such as remotely operated medical devices, where a security breach may result in detrimental or even life threatening scenarios. Therefore, steps must be taken to ensure that data is transferred correctly and securely. 
     While some electronic devices afford limited protection by employing secure microcontrollers that add encryption to data prior to upstream transmission over a digital network, unsecured data at the device level and the microcontroller itself remain vulnerable to attack. Existing approaches leave the communication system still at significant risk of intentional data manipulation by potential intruders that seek out opportunities to interfere with networked devices that transmit or receive data. Data integrity of existing electronic devices is relatively easily compromised as no security measures are applied to the data prior to being secured by the microcontroller. Additionally, devices in which data is converted from digital to analog format or vice versa are oftentimes not equipped to verify the validity of the source of the data to ensure that transmitted data is sufficiently trustworthy to provide a desired level of protection. 
     What is need are tools to overcome the above-described limitations. 
     SUMMARY OF THE INVENTION 
     Various embodiments provide for optimized data security at a physical interface prior to sending the data upstream. In certain embodiments, data is digitized and secured at the point of information generation before being transmitted so as to ensure full chain of custody of the data. 
     Some embodiments provide for a security layer that is applied to the data within an electronic device that facilitates data conversion, such that the data remains safe from being compromised upstream later. Other data security operations include two-way authentication that requires validation of control commands prior to permitting modifications to a device coupled to a physical interface point. This ensures that data the device receives at the physical interface is valid and authorized and, thus, decisions based on that data are trustworthy. 
     Certain features and advantages of the present invention have been generally described here; however, additional features, advantages, and embodiments are presented herein will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims hereof. Accordingly, it should be understood that the scope of the invention is not limited by the particular embodiments disclosed in this summary section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments. 
       Figure (“FIG.”)  1  shows a prior art system for securely transferring data. 
         FIG. 2  shows an exemplary system that implements secure data processing according to various embodiments of the invention. 
         FIG. 3  is an exemplary functional block diagram of a sensor to securely process data according to various embodiments of the invention. 
         FIG. 4  is an exemplary functional block diagram of an actuator to securely process data according to various embodiments of the invention. 
         FIG. 5  is a flowchart of an exemplary process for securely processing data according to various embodiments of the invention. 
         FIG. 6  is a flowchart of another exemplary process for securely processing data according to various embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the invention. It will be apparent, however, to one skilled in the art that the invention can be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, described below, may be performed in a variety of ways and using a variety of means. Those skilled in the art will also recognize that additional modifications, applications, and embodiments are within the scope thereof, as are additional fields in which the invention may provide utility. Accordingly, the embodiments described below are illustrative of specific embodiments of the invention and are meant to avoid obscuring the invention. 
     Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearance of the phrase “in one embodiment,” “in an embodiment,” or the like in various places in the specification are not necessarily referring to the same embodiment. 
     Furthermore, connections between components or between method steps in the figures are not restricted to connections that are affected directly. Instead, connections illustrated in the figures between components or method steps may be modified or otherwise changed through the addition thereto of intermediary components or method steps, without departing from the teachings of the present invention. 
       FIG. 1  shows a prior art system for securely transferring data. System  100  includes remote sensor  102 , analog-to-digital converter (ADC)  104 , microcontroller  106 , transceiver  108 , signal  110 , network  112 , service provider  114 , actuator  120 . System  100  receives analog data from remotely located sensor  102 , converts the data into digital format via ADC  104 , and then employs microcontroller  106  to encrypt the digital data. The encrypted data is then forwarded to transceiver  108 , which transmits it to service provider  114  via network  112 . Service provider  114  then decrypts the encrypted data and processes the decrypted data, as needed. 
     Remote sensor  102  is commonly a device that detects or measures a physical property for subsequent transmission to service provider  114 . Remote sensor  102  may be a motion sensor, such as an occupancy sensor; an acoustic sensor, such as a microphone; a magnetic sensor, such as a Hall sensor; a chemical sensor, such as a smoke detector; or a blood pressure sensor that is remotely located and collects data that is then transmitted to service provider  114 . Service provider  114  can be a hospital server that receives the data, decrypts it, and prepares it for a reading by a physician. Remote sensor  102  typically generates an analog output signal that is received by ADC  104  and converted into a digital signal. The digital output signal of ADC  104  is input to microcontroller  106  for encryption. 
     Microcontroller  106  typically is a device that includes a processor that is capable of dynamic processing and storing data in a memory. Microcontroller  106  communicates with any number of devices. Primarily, it receives the digital data from ADC  104  and applies an encryption algorithm that encodes and secures the digital data. Microcontroller  106  then sends the data to service provider  114  via transceiver  108 . Transceiver  108  is a device used to transmit and/or receive information, such as signal  110 , over network  112  and is often implemented as a single device. Network  112  represents any medium over which information can be communicated, such as a local network, a wide area network, a satellite network, etc. Network  112  is used to communicate the physical information that is collected by remote sensor  102  to service provider  114 . 
     Network  112  is also used to transmit commands from service provider  114  to remote sensor  102  or actuator  120 , for example, to effectuate physical action. In that case, encrypted data sent by service provider  114  is first received by transceiver  108  via network  112 . The data is then decrypted by microcontroller  106  prior to being converted to a control command suitable to operate actuator  120 . 
     Actuator  120  may be used to control a physical environment, for example, by adjusting temperature settings or ambient light conditions of the surroundings. Actuator  120  is typically an electromagnetically activated device, such as a switch assembly, that monitors an external circuit and responds to a control command received from service provider  114  and verified by microcontroller  106 , which deciphers the encryption digital data command received from service provider  114 . In some applications, actuator  120  converts digital data representing actions to be taken into analog data and acts upon a secured digital data command or instructions received from microcontroller  106 . 
     However, neither remote sensor  102  nor actuator  120  are usually designed to verify the validity of the data these devices exchange with microcontroller  106 . This leaves system  100  vulnerable to attack and re-programming by potential hackers; especially, when system  100  operates in an automated or semi-automated manner. Therefore, it would be desirable to have a system that ensures that all data within the communication system is transmitted securely and, thus, provides a high level of protection. 
       FIG. 2  shows an exemplary system that implements secure data processing according to various embodiments of the invention. System  200  includes physical data interface  202 , data converter  204 , which further comprises security block  206 , communication channel  208 , and host  210 . Physical data interface  202  is configured to interact with a user or a device. Interface  202  may be coupled to a remote sensor (not shown) that generates, for example, analog data representing measured data taken at physical data interface  202 . The sensor is any type of sensor, such as a temperature sensor, a blood pressure sensor, or a pulse oximetry sensor that is remotely located to collect data and generate a signal, such as a voltage, that can then be converted into a data signal. The data signal is representative of a physical property (e.g., temperature, illumination level, noise level, etc.) measured by the sensor. One skilled in the art will appreciate that physical data interface  202  may communicate with any number of devices, including actuators and transducers that may be configured to receive from host  210  commands representing instructions to effectuate an action or execute instructions. 
     Data converter  204  is configured to convert the format of data transmitted between physical data interface  202  and host  210 . Data converter  204  comprises an ADC or digital-to-analog converter to convert analog data to digital data or vice versa. For example, analog measurement data taken by a remote sensor may be converted into digital data. In one embodiment, data converter  204  is implemented as a Programmable  10  (PIO). 
     In one embodiment, data converter  204  converts command data received from host  210  from a digital format to a corresponding analog format to enable a sensor or actuator coupled to physical data interface  202  to take a desired action. In addition to converting data, data converter  204  is configured to provide increased data security via security block  206 . Security block  206  is configured to apply a security algorithm to data received from at least one of physical data interface  202  and host  210 . Data converter  204  may also be configured to determine whether received data is secure. Details and examples of securing data by using various security protocols that can be employed by security block  206  are described below. 
     Depending on the type of data to be transferred, data may be secured prior, simultaneously with, or after conversion from one format to another. In one embodiment, data to be transmitted from physical data interface  202  to host  210  may be converted from analog to digital within data converter  204  prior to being secured by security block  206 . In another example, when data is transmitted from host  210  to physical data interface  202 , data may be secured and/or authenticated by security block  206  prior to being converted from digital to analog format. 
     Security block  206  is a device configured to secure or validate data, and execute any number of security protocols. Security block  206  may be implemented as a standalone hardware module or embedded into data converter  204 . In one embodiment, security block  206  is a Security Algorithm Hardware Accelerator (SAHA) that is configured to manage the security of data to be transferred. In one embodiment, security block  206  is configured to apply a security protocol to the transmitted data to ensure data security. The security protocol, which may be pre-programmed, may add a security layer to the data or remove security-related information from the data. Security block  206  performs at least one of numerous security methods, including encryption, decryption, and authentication of security protocols. 
     The security protocol may also be used to encrypt and authenticate data. The security methods used by the security protocols comprise, for example, symmetric key hash functions, Public Key/Private Key Digital Signatures (PKDS), and/or full encryption. Authorization methods of data comprises, for example, encryption, authentication, validation, and decryption. Symmetric key hash functions are programmable modules that authenticate data to be transferred. Examples of symmetric key hash functions are Secure Hash Algorithm 1 (SHA-1) or Secure Hash Algorithm 2 (SHA-2). Public Key/PKDS are programmable modules that authenticate data to be transferred. Examples of PKDS functions include, for example, Elliptic Curve Digital Signature Algorithm (ECDSA). Full encryption functions are programmable modules that authenticate data to be transferred. Examples of full encryption methods include, for example, the Data Encryption Standard (DES), Triple Data Encryption Standard (3-DES), and the Rivest-Shamir-Adleman method (RSA). The security protocols of security block  206  may also determine the validity of the data to be transferred. In one embodiment, system  200  determines that the data received is incomplete or has been tampered with based on inconsistencies in the data. 
     Communication channel  208  is coupled between data converter  204  and host  210  to establish communication from host  210  to a data converter  204  and vice versa. Communication channel  208  is used to communicate over any wired or wireless protocol known in the art, including, Wi-Fi, Wi-Max, 4G LTE, UMTS, infrared, and Zigbee. In one embodiment, communication channel  208  is a cellular data network that establishes communication between a cellular device and host  210 . 
     Host  210  is any upstream device, such as a remote server. Host  210  may comprise a non-transitory logic circuit capable of processing data and communicating with data converter  204  via communication channel  208  to exchange information. For example, host  210  may be a service provider that sends and receives information in order to provide a particular service. The services provided may include monitoring of health information via remote sensors that are coupled to physical data interface  202 , and sending commands to the sensors to change the setting of a health monitor, adjust a medical device, or adjust a room temperature. 
     System  200  may communicate with any other element of the system using protocols, such as 1-Wire®, universal asynchronous receiver/transceiver (UART), inter-integrated circuit (I 2 C), serial peripheral interface (SPI), radio frequency (RF), wireless (Wi-Fi, Wi-Max), Ethernet, universal serial bus (USB), or any other suitable protocol. 
     In one embodiment, system  200  comprises a sensor and an actuator (not shown) coupled to physical data interface  202 . The sensor is configured to securely transfer data to host  210  and receive a command response from host  210 . Based on the data, system  200  then takes action based on the command response using the actuator. In one embodiment, system  200  is entirely automated, such that in operation no human interaction is required. In this example, system  200  comprises an insulin level sensor coupled to physical interface  202  to detect insulin level data and transmit the information to host  210 . An insulin pump coupled to physical interface  202  serves as an actuator that receives instructions from host  210  and responds to a command by adjusting the insulin dispense rate of a patient to an appropriate, predetermined value. The bi-directional data transmitted between sensor and host  210  are, thus, secured by system  200 . 
     One skilled in the art will appreciate that system  200  may comprise additional components necessary for converting, processing, and securing data, such as logic devices, interface devices, power sources, and memory. 
       FIG. 3  is an exemplary functional block diagram of a sensor to securely process data according to various embodiments of the invention. Secure sensor  300  comprises signal converter  310 , SAHA  308 , which may comprise a digital certificate and/or embedded secret, dedicated state logic  306 , and protocol interface  304 . Secure sensor  300  may communicate with a host or any other computing system known to one of skill in the art via communication channel  302 . 
     Signal converter  310  is, for example, an ADC that receives input signal  312  in the form of an unsecured analog or digital signal. Input signal  312  is an application stimulus that comprises information, such as data representative of an environmental condition or event, an input level, etc. In one embodiment, signal converter  310  converts unsecured signal  312  into a digital data signal that is subsequently secured by SAHA  308 . 
     SAHA  308  is any device configured to process and secure the unsecured digital data received from signal converter  310 . SAHA  308  accomplishes this by numerous security methods, including the use of symmetric key hash functions, electronic signatures using public or private keys, encryption, and other security protocols. In one embodiment, SAHA  308  comprises a digital certificate and/or embedded secret and combines those elements with the unsecured data to generate secured data. 
     Dedicated state logic  306  is any logic circuit configured to interpret digital commands received from an external device, such as a host. In one embodiment, dedicated state logic  306  determines the validity of data that protocol interface  304  receives via communication channel  302  before sending request signal  314  to signal converter  310 . Request signal  314  enables signal converter  310  to convert input signal  312  and to forward the converted signal to SAHA  308 . 
     In one embodiment, if dedicated state logic  306  determines that the digital data it received from protocol interface  304  or any portion of that data (e.g., a digital command) is invalid or unauthorized, then state logic  306  refuses to send request signal  314  to signal converter  310  and/or to forward the processed and secured data to the host via protocol interface  304 . On the other hand, if dedicated state logic  306  determines that the digital data received from protocol interface  304  comprises a valid digital data command issued by the host, state logic  306  initiates a signal conversion by signal converter  310  via request signal  314 . 
     Signal converter  310  monitors input signal  312 , which, as discussed, may be an analog stimulus that is converted by signal converter  310 . In one embodiment, data resulting from the signal conversion, along with an embedded secret that is known to the host, are loaded into SAHA  308 . The converted signal, together with a hash resulting from the security algorithm (i.e., a Message Authentication Code or MAC), are passed back to the host via protocol interface  304 . Based on the hash the host may then verify the authenticity of the received data. 
     In one embodiment, state logic  306  receives digital data from protocol interface  304 , interprets the data, and initiates a signal conversion by signal converter  310 . The converted data generated by signal converter  310  is loaded into SAHA  308 . SAHA  308  uses an embedded secret, such as a previously installed Private Key, to generate a digital signature. The digital signature, a digital certificate that is pre-installed into SAHA  308 , and the resulting data from the signal conversion are passed to the host via protocol interface  304 . The host may then verify the digital certificate and use a corresponding Public Key to verify the authenticity of the digital signature. 
     In one embodiment, the converted data is loaded into SAHA  308  along with an embedded secret with which SAHA  308  performs an encryption on the converted data. The encrypted data is passed to a host that shares the same secret with SAHA  308  and uses the secret to decrypt the converted data to ensure that the data was transferred correctly and securely. 
       FIG. 4  is an exemplary functional block diagram of an actuator to securely process data according to various embodiments of the invention. Similar to  FIG. 3 , secure actuator  400  comprises protocol interface  404 , SAHA  406 , state logic  408 , and signal converter  410 . Protocol interface  404  is coupled to a communication channel  402  to receive data transmitted to actuator  400  from an upstream device, typically a host or any other computing system. The data may comprise digital data, including a control command, such as a an input message and a MAC, to control an application via signal  412  that is generated by actuator  400 . Control signal  412  may be a digital-to-analog voltage signal, a PIO, a transducer input, etc. 
     Protocol interface  404  receives data via communication channel  402  and forwards it to SAHA  406 . SAHA  406  applies a security protocol to the data. Security protocols include symmetric key hash functions, PKSD, or full encryption, which may alter the data with a Public Key and/or a secret embedded in SAHA  406 . 
     In one embodiment, dedicated state logic  408  receives a secured digital data command processed by SAHA  406  and determines whether the command is valid. If so, dedicated state logic  408  initiates signal conversion by signal converter  410 . Signal converter  410  may be a data converting device, such as a DAC, that converts the command into an analog data format. Analog signal  412  may be then transmitted to a device, such as an actuator or a transducer, that is designed to effectuate a received command. 
     In one embodiment, protocol interface  404  receives data comprising a command and a MAC sent by a host. Both are loaded into SAHA  406  and hash operation is performed on the command using a secret embedded in SAHA  406 . The hash data resulting from the operation is compared to the MAC. If the hash data and the MAC match, state logic  408  determines that the command is authentic and forwards the authenticated command to signal converter  410  to commence a signal conversion. Conversely, if protocol interface  404  fails to receive the correct MAC, such that the comparison fails to produce an appropriate match, state logic  408  determines that the data is invalid and rejects the command. A signal conversion does not occur. 
     In one embodiment, SAHA  406  receives from a host, via protocol interface  404 , data  402  comprising a digital certificate and a digital data command that is digitally signed by the host&#39;s Private Key. Both the digital signature and certificate are loaded into SAHA  406 . SAHA  406  verifies the authenticity of the certificate by using a secret embedded in SAHA  406 . The authenticity of the digital signature is verified using the host&#39;s Public Key. If both the digital signature and the certificate are deemed authentic and the command is valid, state logic  408  causes signal converter  410  to commence a signal conversion. However, if either the digital signature or the digital certificate are not authentic or the command is not valid, state logic  408  rejects the command and no signal conversion occurs. 
     In one embodiment, data  402  is an encrypted digital data command that is loaded into SAHA  406 , where it is decrypted using a secret embedded in SAHA  406 . If the decrypted command is valid, state logic  408  causes signal converter  410  to commence a signal conversion. Conversely, if the decrypted command is not valid, state logic  408  rejects the command and signal conversion does not occur. 
       FIG. 5  is a flowchart of an exemplary process for securely processing data according to various embodiments of the invention. The process to securely process and transmit data begins at step  502  by receiving a digital data command from a host, e.g., via a secure communication network or channel. The command comprises data representing, for example, a request to receive a sensor reading. 
     At step  504 , a signal is generated that comprises data representing, for example, a physical property measured at a physical interface. In one embodiment, a security device may determine whether the data or the source from which the data was transmitted is valid. 
     At step  506 , the signal generated in step  504  is converted into data. For example, the signal may be converted from an analog voltage signal into digital data. Signal conversion may take place automatically, in response to the digital data command, or in response to a request signal received by a signal converter. 
     At step  508 , the converted data is secured, for example, by using a security device that applies a security protocol to the data. The security protocol may include encryption, applying a secret to the data, such as a hash algorithm, appending a digital signature or a certificate, and the like. 
     Finally, at step  510 , the secured data is transmitted to a host via a suitable communication channel. 
       FIG. 6  is a flowchart of another exemplary process for securely processing data according to various embodiments of the invention. The process begins at step  602  when data, for example, in the form of a digital data command, is received from a host. The host may have already secured the digital data prior to transmission using a security protocol. The digital data command may comprise a request to initiate an action. 
     At step  604 , the digital data is loaded into a SAHA or any other secure device capable of determining the validity of data or the source thereof. 
     At step  606 , it is determined whether the data is valid. For this purpose, the SAHA may apply a security protocol (e.g., a symmetric key hash function, Public Key/PKDS, full encryption) in order to determine the validity of the data. If it is determined that the data is valid, then process  600  proceeds to step  608  where the data is converted, for example, from digital to analog format. On the other hand, if the data is deemed invalid or if the SAHA determines that the data is not verified at step  606 , then step  608  fails to occur and the process returns to step  602  and the host may retransmit the data. 
     Finally, at step  610  an action, including e.g., a system change or a system reconfiguration is initiated based on the verified and converted data. The action may be performed by an internal or external actuator, a PIO, a transducer, etc. 
     It will be appreciated by those skilled in the art that fewer or additional steps may be incorporated with the steps illustrated herein without departing from the scope of the invention. No particular order is implied by the arrangement of blocks within the flowchart or the description herein. 
     It will be further appreciated that the preceding examples and embodiments are exemplary and are for the purposes of clarity and understanding and not limiting to the scope of the present invention. It is intended that all permutations, enhancements, equivalents, combinations, and improvements thereto that are apparent to those skilled in the art, upon a reading of the specification and a study of the drawings, are included within the scope of the present invention. It is therefore intended that the claims include all such modifications, permutations, and equivalents as fall within the true spirit and scope of the present invention.