in accordance with the recent increases in human life expectancy and income , the medicalhealthcare paradigm is gradually expanding to include post - treatment , prevention , and health management .
it has become a serious challenge to meet the rise in expectations regarding medical services , while there is a lack of professionals in the field of welfare among other problems . narrowly defined , ' remote medical service ' means the provision of limited medical services , such as diagnosis and treatment via communication tools as the medium without direct meeting between patient - doctor or doctor - doctor
. however , the range of medical services delivered remotely has steadily expanded , and currently , the concept has expanded to include all types of health management service .
remote medical services can largely be classified into the following three categories : ' telemedicine ' , which allows for initial diagnosis by the doctor viewing the condition of the patient via a device that supports video imagery ; ' remote monitoring ' , which allows for constant checking of information for an extended period of time and personalized diagnosis for treatment of chronic illness ; and lastly , ' remote con trol ' of remote diagnosisremote treatment , etc . , which utilize new information and communications technology .
central to acquiring data for medical use is data acquisition and utilization technology in remote medical technologies .
such technology can utilize sensing technology and internet of things ( iot ) technology , which include wearable technology , making more concrete realization possible , and studies in the healthcare field utilizing these applied technologies are actively being conducted nowadays .
however , in the iot environment where a variety of data should be continually transmitted and processed , taking only partial security issues into consideration has led to seemingly small security threats can , in fact , be a threat to human lives .
furthermore , to support remote medical services in the iot environment , previous studies have attempted to change services in accordance with sub - elements , and there is a constraint in that the entire structure should be restructured when security elements are added or a new service is created . accordingly , there is a need for a method and structure that can satisfy the security demands of existing remote medical services and can dynamically support security demands regarding newly created ser vices . in short , there is a need for studies regarding a new method and structure for remote medical services in the iot environment .
this study aimed to provide flexibility regarding new services and security elements through a service - oriented structure .
the proposed framework supports dynamic security elements for each service by including security elements throughout the entire process from the creation to the destruction of data .
here , we describe various types of remote medical services and define common elements and structures that serve as a basis for remote medical services in the iot environment . in addition , the structural and functional limitations of the remote medical environment based on the defined elements are extracted . first
, ' remote treatment ' is one type of medical service that is being developed that strives to overcome geographic and time - related obstacles .
remote treatment service was introduced for prisoners of the full sutton prison located in a suburb of the city of york by airedale nhs foundation trust of the united kingdom in 2006 .
the kiosk - type unmanned telemedicine system ' healthspot station ' , which was introduced on consumer electronics show ( ces ) in 2013 , is an installation - type clinic where various types of physical examination in addition to video treatment by a doctor are possible within the designated space .
this includes many services , such as welldoc bluestar , which is a remote diabetes management mobile software approved by the us food and drug administration , and phonedoctorx , which allows a professional medical team in a remote location to view the abnormal conditions that occur during regular nursing care of a facility resident via video phone to assist in decision - making . next , ' remote monitoring ' started with technology introduced in the aerospace program of the former soviet union to detected the signals of living organisms for remote communication .
this technology also made it possible for nasa to collect biometric data and check predictable physical funct ions in advance to allow for remote response while astronauts conducted their work . according to the frost & sullivan survey ,
the growth rate of the remote monitoring market has maintained double digits in the past 10 years , and it is currently expected to achieve remarkable advances in the development of wearable devices and data sensing technology centering on iot . ultimately , this research will enable medical consumers , such as cancer patients and patients with chronic illnesses , to have their health condition constantly monitored by medical staff and to have a ' designated doctor ' who can provide them with medical services regardless of time and place .
finally , remote ' diagnosistreatmentcontrol ' management are being attempted along with various technological developments .
sunnyvale , ca , usa ) , which is famous for application in robot - assisted surgical procedures , has proven the effect by attempting an operation from a remote location focusing on many large domestic hospitals .
in addition , ibm watson analyzes big data within 3 seconds , focusing on 600,000 clinical data and 42 medically related db , in providing a practical advice service to medical staff .
furthermore , asklepios hospital , located in hamburg , germany , has attempted to utilize augmented reality by overlapping an actual photograph based on a pre - operation clinical image of the patient in operation .
various efforts are being made around the world to provide diverse remote medical services , including changi general hospital in singapore , which uses qr codes to manage personalized administration for each patient via robot .
the technology that serves as the basis for the remote medical services mentioned above is presented in figure 1 .
the structure makes data collection from sensors and devices , pro cessing , transmission , execution , analysis , and other actions possible to support remote medical services . for remote medical services in such a structure , change in service
is inevitable in accordance with sub - elements , including network technology , protocol , sensor , device , etc . also , there is a constraint in that the structure should be restructured whenever a new service is created .
the same problem occurs when a security service and technology is applied to a remote medical environment . when the required factors of iot , human , object , and service are applied to the remote medical environment , ' human '
is subdivided into classifications of patient , medical personnel , and non - patient . '
object ' refers to all objects and infrastructure on the internet located around the ' human ' element , in other words patients , medical personnel , and non - patients .
lastly , ' service ' is media that expresses and supports medical communication between human - object - infrastructure .
accordingly , remote medical services with an iot architecture can be classified into the following three layers : 1 ) the perception layer , which receives health signal entries from various sensors ; 2 ) the network layer , which takes on the role of transmitting the health data from the perception layer to the application layer ; and 3 ) the application layer , which provides various services and interfaces via the health data received from the network layer .
consequently , the security elements of the remote medical architecture should be included at the initial design level because simple cyber - attacks can be directly connected to threats against patients ' lives .
a service - oriented architecture is flexible and can support a combination of applications depending on telemedicine environmental changes .
therefore , this study was focused on designing a service - oriented architecture and security for remote medical services .
if remote medical services are carried out in the iot environment , security vulnerability in the general remote medical setting and security vulnerability in the iot environment will both be present .
therefore , in this section , the remote medical security threats in the iot environment that take both conditions into consideration are extracted , and then security demands regarding these threats are described .
we describe the threats that can occur if certain elements are not considered during the provision of remote medical services in the iot environment .
1 ) if device authentication is not taken into consideration : in other words , if access to all devices is indiscreetly permitted without certifying the device ( or sensor ) in the remote medical services in iot environment , the credibility of the collected medical data can not be guaranteed .
2 ) if role and situation - based access control is not taken into consideration : accurate decision and control regarding various conditional device ( or sensor ) accesses , which can occur during the provision of remote medical services in the iot environment , will be difficult .
3 ) if user authentication is not taken into consideration : if authentication regarding patients and medical staff , who are the main agents of telemedicine , is not considered , remote monitoring , and control , are unclear . in such a case , preventing medical practice of unauthorized person , misuse of remote medical services , and accountability of medical practice will be impossible .
in addition , security threats that can be caused by iot , as well as the structure and characteristics of remote medical services also exist , as seen in table 1 .
accordingly , we extracted threats from this case and table 1 to prevent security threats against remote medical services in the iot environment and to protect the privacy of patients . a method that can overcome the challenges regarding confidentiality , integrity , and availability is needed .
collection of various types of data from devices ( or sensors ) should be secure .
therefore , the following security requirements should be satisfied for the entire process from acquisition to destruction .  confidentiality : personal health information should not be disclosed to unauthorized access during transmission .
therefore , only authorized devices , networks , and users should be able to use the information after the authentication process between the perception layer , network layer , and application layer .
furthermore , a function that allows confidentiality selection should be provided regarding items related to invasion of privacy in which individual specifics exist .
 integrity : the data transmitted by the sender and the data received by the receiver should be consistent .
measures including authentication , encryption , security channel , and others are requested for the protection of integrity during data transmission .
an integrity protection measure is also necessary to prevent unauthorized data modification regarding previously stored data . 
availability : delays , bottlenecks and other problems that degrade availability should not occur in data processing , even when it includes security measures with confidentiality , integrity , authentication , non - repudiation , and so on . in particular , sensitive devices and services that can be directly related to a patient 's life , require 2 - 3 layers of guarantee measure for availability . 
authentication : authentication is the process to determine whether or not someone is an actual user , and it is required before data access
. in particular , access control of remote medical services considering a variety of factors should meet the demands for mobility and timeliness .
 non - repudiation : non - repudiation is required to ensure accountability regarding specific acts . in the remote medical environment
specifically , certification of authentication technology based on a public - key is required to secure reliability between medical activities .
 privacy : privacy means that personal secrets can not be disclosed without consent . in remote medical services with iot
, security measures should be provided for handling sensitive information ( e.g. , name , address , health history , disease information , etc . )
related to individuals . the proposed framework is composed of a total of five layers , including the application service layer , service support layer , network layer , perception support layer , and perception layer .
the application service layer offer a convenient user interface to patients , medical staff , and non - patients .
it is supplied with data and resources from the service support layer based on requests by the service . in each of the service applications , independent service with reinforced security exists .
the service support layer manages data and resources which serve as the basis for the efficient performance of the application service layer .
it takes the data transmitted by the perception support layer and stores it in an integrated database through the second access controller .
the service mgr ( service management ) , data mgr ( data management ) , resource mgr ( resource management ) , and system clock manage and supply service , data , resource , and time data regarding the application service . the a_en / decryptor encrypts ( or decrypts ) the data received from the a_communicator .
the a_communicator receives the data from the p_communicator , and then the data is forwarded to the second access controller ( or a_en / decryptor ) .
it handles direct and indirect data communication between the service support layer and perception support layer .
the perception support layer collects the data received from the perception layer and controls bad data and unauthorized access .
after that , it performs pretreatment to ensure that the data collected from different types of devices and sensors can be used appropriately .
the p_encryptor encrypts the data received from the classifier , and the p_communicator sends the data that was received from the p_encryptor and classifier .
the perception layer is the domain in which the device ( or sensor ) that creates data exists .
various types of data created in this layer are transmitted to the perception support layer . in the next section ,
we focus on the perception side layer and application side layers , which are the core territories of remote medical services with iot , in adding each network elements to propose framework , which will be separated into two sections , namely , the a - n section and n - p section , in the explanation .
the n - p section refers to the perception support layer , perception layer , and network layer , while the a - n section refers to the application service layer , service support layer , and network layer .
the a - n section of the proposed framework includes parts that perform important functions , including management of the application service layer and supplying data and resource , and thorough access control should be conducted regarding this .
access control is handled by the contextual - based access control ( cbac ) technique , which is based on time and spatial data and takes timely and migratory characteristics of the subject of control into consideration , as well as role - based access control ( rbac ) , which allows flexible control in accordance with a complex environment and group .
next , we explain the access control process utilizing cbac and rbac . the terms and constraints used in cbac are presented in table 2 .  authentication by cbac : uses cbac , which is a technique that controls access through contextual information .
it verifies whether the confirmed timely - spatial information and system standard time value are within the permitted range ( min : minimum value , max : maximum value ) . if the result is true , access validity is decided after verification that the scanned access location is within the permitted location range .
authentication by rbac : in this stage , rbac is used , which controls access via role information .
limited to access with first round of authentication complete , the access profile of the service access attempter and previously registered access profile stored into db , are checked for consistency .
if the result is true , the role is verified to check whether the requested role is an authorized role in deciding the second round of authentication .
the n - p section is the part that handles device and sensor access as well as preprocessing , classification , and processing of the data received from it , and security measures during data processing should be available .
security during data processing uses data authentication , encryption , and security channel of reliable device .
.  authentication of device : valid devices are identified by comparing the initially verified device i d and device i d with authorized access . in the case of a valid device , the device i d and the current time from the device ( sensor ) and collection gateway are put through exclusive - or .
then , based on the created value , each of the created otp values is compared in completion of the final first authentication . the device authentication process is shown in table 5 . in the proposed framework , for secure and prompt processing of various types of health data obtained from sensors and devices ,
the data is processed separately in classification stages , including preprocessing in a secure mode that processes it into an appropriate form for processing and an actual processing stage .
preprocessing : this stage divides the data into efficient data processing units and removes mixed in data that exceeds the range or is not permitted , prior to processing . in this stage ,
 classification : security mode application usage is determined regarding data that has had unnecessary raw data and error values removed and separated into efficient processing units .
the units are distributed into secure mode and normal mode with applied security processing in accordance with the mode value for each hardware i d defined in preprocessing .  processing : if general data without security application is processed , it is classified into normal mode , which applies the general processing method , and secure mode , which selectively applies security measures , including authentication , encryption , security channel , etc . , in situations requiring security .
next , we describe how the data classified into secure mode for the purposes of secure processing of data are processed .
table 6 shows an example that defines whether or not the security elements are applied to authentication , secure channel , data encryption regarding received data from applicable devices and sensors after the security mode has been determined for each device and sensor .
as shown in figure 4 , secure mode applies the security element in accordance with security level ( 1 - 3 ) .
then , data encryption / decryption and secure channel are selectively applied , following the user definition .
the applied method uses each hardware i d and application mode , encryption and security channel application execution of hardware i d and secure mode table as reference in processing .
 authentication ( essential ) : authentication , which is the process of verifying the validity of a user , blocks unauthorized access regarding important data or personal data that should kept confidential through authentication of data classified as secure mode .
 data encryption / decryption ( optional ) : by encrypting the data with a mathematically verified symmetric key encryption and algorithm , it prevents plaintext exposure of transmitted sensitive data . if the encrypted data was modulated during transmission , data integrity can also be verified because decoding is not possible .  secure channel ( optional ) : during network transmission between two points , an asymmetric key encryption algorithm and electronic signature should be used to prevent exposure of transmission status and transmission data by composing a security channel ( virtual network ) during the connection of a separate sender and receiver in cases of data requiring stronger security . here
, we present a medical service scenario in which a secure remote medical service is provided in the iot environment with proposed framework application .
table 7 defines the medical service - oriented terms and figure 5 displays a diagram based on the proposed framework .
whether security technology is applied to each of stages - is explained in relation to the process .
 transfer of perception data : verify through da between device ( or sensor)-device ( or sensor ) , device ( or sensor)-collection gateway , and transmit data securely through sc , ded during data transmission .
 the collected data transferring and preprocessing from device ( or sensor ) : after completing da on the collection gateway , cbac and rbac should be applied to transmit the collected data .
if additional security is required , ded and sc should be used because they make it possible to provide strong security service .
, transferred data update and access to electronic medical records : the ua used when accessing the electronic medical records of the medical staff and others , including ded , sc , cbac , and rbac are shown in . , providing the services to users : da is used when device and sensor transmit data from the user ( non - patient , patient ) . on the other hand , when the user wishes to access a service , the ua is used .
the application of cbac and rbac is required during data transmission between user - service ; sc and ded are selectively provided for stronger security .
here , we describe various types of remote medical services and define common elements and structures that serve as a basis for remote medical services in the iot environment . in addition , the structural and functional limitations of the remote medical environment based on the defined elements are extracted . first
, ' remote treatment ' is one type of medical service that is being developed that strives to overcome geographic and time - related obstacles .
remote treatment service was introduced for prisoners of the full sutton prison located in a suburb of the city of york by airedale nhs foundation trust of the united kingdom in 2006 .
the kiosk - type unmanned telemedicine system ' healthspot station ' , which was introduced on consumer electronics show ( ces ) in 2013 , is an installation - type clinic where various types of physical examination in addition to video treatment by a doctor are possible within the designated space .
this includes many services , such as welldoc bluestar , which is a remote diabetes management mobile software approved by the us food and drug administration , and phonedoctorx , which allows a professional medical team in a remote location to view the abnormal conditions that occur during regular nursing care of a facility resident via video phone to assist in decision - making . next , ' remote monitoring ' started with technology introduced in the aerospace program of the former soviet union to detected the signals of living organisms for remote communication .
this technology also made it possible for nasa to collect biometric data and check predictable physical funct ions in advance to allow for remote response while astronauts conducted their work . according to the frost & sullivan survey ,
the growth rate of the remote monitoring market has maintained double digits in the past 10 years , and it is currently expected to achieve remarkable advances in the development of wearable devices and data sensing technology centering on iot . ultimately , this research will enable medical consumers , such as cancer patients and patients with chronic illnesses , to have their health condition constantly monitored by medical staff and to have a ' designated doctor ' who can provide them with medical services regardless of time and place .
finally , remote ' diagnosistreatmentcontrol ' management are being attempted along with various technological developments .
sunnyvale , ca , usa ) , which is famous for application in robot - assisted surgical procedures , has proven the effect by attempting an operation from a remote location focusing on many large domestic hospitals .
in addition , ibm watson analyzes big data within 3 seconds , focusing on 600,000 clinical data and 42 medically related db , in providing a practical advice service to medical staff .
furthermore , asklepios hospital , located in hamburg , germany , has attempted to utilize augmented reality by overlapping an actual photograph based on a pre - operation clinical image of the patient in operation .
various efforts are being made around the world to provide diverse remote medical services , including changi general hospital in singapore , which uses qr codes to manage personalized administration for each patient via robot .
the technology that serves as the basis for the remote medical services mentioned above is presented in figure 1 .
the structure makes data collection from sensors and devices , pro cessing , transmission , execution , analysis , and other actions possible to support remote medical services . for remote medical services in such a structure , change in service
is inevitable in accordance with sub - elements , including network technology , protocol , sensor , device , etc . also , there is a constraint in that the structure should be restructured whenever a new service is created .
the same problem occurs when a security service and technology is applied to a remote medical environment . when the required factors of iot , human , object , and service are applied to the remote medical environment , ' human '
is subdivided into classifications of patient , medical personnel , and non - patient . '
object ' refers to all objects and infrastructure on the internet located around the ' human ' element , in other words patients , medical personnel , and non - patients .
lastly , ' service ' is media that expresses and supports medical communication between human - object - infrastructure .
accordingly , remote medical services with an iot architecture can be classified into the following three layers : 1 ) the perception layer , which receives health signal entries from various sensors ; 2 ) the network layer , which takes on the role of transmitting the health data from the perception layer to the application layer ; and 3 ) the application layer , which provides various services and interfaces via the health data received from the network layer .
consequently , the security elements of the remote medical architecture should be included at the initial design level because simple cyber - attacks can be directly connected to threats against patients ' lives .
a service - oriented architecture is flexible and can support a combination of applications depending on telemedicine environmental changes .
therefore , this study was focused on designing a service - oriented architecture and security for remote medical services .
if remote medical services are carried out in the iot environment , security vulnerability in the general remote medical setting and security vulnerability in the iot environment will both be present .
therefore , in this section , the remote medical security threats in the iot environment that take both conditions into consideration are extracted , and then security demands regarding these threats are described .
we describe the threats that can occur if certain elements are not considered during the provision of remote medical services in the iot environment .
1 ) if device authentication is not taken into consideration : in other words , if access to all devices is indiscreetly permitted without certifying the device ( or sensor ) in the remote medical services in iot environment , the credibility of the collected medical data can not be guaranteed .
2 ) if role and situation - based access control is not taken into consideration : accurate decision and control regarding various conditional device ( or sensor ) accesses , which can occur during the provision of remote medical services in the iot environment , will be difficult .
3 ) if user authentication is not taken into consideration : if authentication regarding patients and medical staff , who are the main agents of telemedicine , is not considered , remote monitoring , and control , are unclear . in such a case , preventing medical practice of unauthorized person , misuse of remote medical services , and accountability of medical practice will be impossible .
in addition , security threats that can be caused by iot , as well as the structure and characteristics of remote medical services also exist , as seen in table 1 .
accordingly , we extracted threats from this case and table 1 to prevent security threats against remote medical services in the iot environment and to protect the privacy of patients . a method that can overcome the challenges regarding confidentiality , integrity , and availability is needed .
collection of various types of data from devices ( or sensors ) should be secure .
therefore , the following security requirements should be satisfied for the entire process from acquisition to destruction .  confidentiality : personal health information should not be disclosed to unauthorized access during transmission .
therefore , only authorized devices , networks , and users should be able to use the information after the authentication process between the perception layer , network layer , and application layer .
furthermore , a function that allows confidentiality selection should be provided regarding items related to invasion of privacy in which individual specifics exist .
 integrity : the data transmitted by the sender and the data received by the receiver should be consistent .
measures including authentication , encryption , security channel , and others are requested for the protection of integrity during data transmission .
an integrity protection measure is also necessary to prevent unauthorized data modification regarding previously stored data . 
availability : delays , bottlenecks and other problems that degrade availability should not occur in data processing , even when it includes security measures with confidentiality , integrity , authentication , non - repudiation , and so on . in particular , sensitive devices and services that can be directly related to a patient 's life , require 2 - 3 layers of guarantee measure for availability .
 authentication : authentication is the process to determine whether or not someone is an actual user , and it is required before data access
. in particular , access control of remote medical services considering a variety of factors should meet the demands for mobility and timeliness .
 non - repudiation : non - repudiation is required to ensure accountability regarding specific acts . in the remote medical environment
specifically , certification of authentication technology based on a public - key is required to secure reliability between medical activities . 
privacy : privacy means that personal secrets can not be disclosed without consent . in remote medical services with iot
, security measures should be provided for handling sensitive information ( e.g. , name , address , health history , disease information , etc . )
we describe the threats that can occur if certain elements are not considered during the provision of remote medical services in the iot environment .
1 ) if device authentication is not taken into consideration : in other words , if access to all devices is indiscreetly permitted without certifying the device ( or sensor ) in the remote medical services in iot environment , the credibility of the collected medical data can not be guaranteed .
2 ) if role and situation - based access control is not taken into consideration : accurate decision and control regarding various conditional device ( or sensor ) accesses , which can occur during the provision of remote medical services in the iot environment , will be difficult .
3 ) if user authentication is not taken into consideration : if authentication regarding patients and medical staff , who are the main agents of telemedicine , is not considered , remote monitoring , and control , are unclear . in such a case , preventing medical practice of unauthorized person , misuse of remote medical services , and accountability of medical practice will be impossible .
in addition , security threats that can be caused by iot , as well as the structure and characteristics of remote medical services also exist , as seen in table 1 .
accordingly , we extracted threats from this case and table 1 to prevent security threats against remote medical services in the iot environment and to protect the privacy of patients . a method that can overcome the challenges regarding confidentiality , integrity , and availability is needed .
collection of various types of data from devices ( or sensors ) should be secure . also remote medical services should not be modified or wiretapped during transmission .
therefore , the following security requirements should be satisfied for the entire process from acquisition to destruction .  confidentiality : personal health information should not be disclosed to unauthorized access during transmission .
therefore , only authorized devices , networks , and users should be able to use the information after the authentication process between the perception layer , network layer , and application layer .
furthermore , a function that allows confidentiality selection should be provided regarding items related to invasion of privacy in which individual specifics exist .
 integrity : the data transmitted by the sender and the data received by the receiver should be consistent .
measures including authentication , encryption , security channel , and others are requested for the protection of integrity during data transmission .
an integrity protection measure is also necessary to prevent unauthorized data modification regarding previously stored data . 
availability : delays , bottlenecks and other problems that degrade availability should not occur in data processing , even when it includes security measures with confidentiality , integrity , authentication , non - repudiation , and so on . in particular , sensitive devices and services that can be directly related to a patient 's life , require 2 - 3 layers of guarantee measure for availability . 
authentication : authentication is the process to determine whether or not someone is an actual user , and it is required before data access
. in particular , access control of remote medical services considering a variety of factors should meet the demands for mobility and timeliness .
 non - repudiation : non - repudiation is required to ensure accountability regarding specific acts . in the remote medical environment
specifically , certification of authentication technology based on a public - key is required to secure reliability between medical activities . 
privacy : privacy means that personal secrets can not be disclosed without consent . in remote medical services with iot
, security measures should be provided for handling sensitive information ( e.g. , name , address , health history , disease information , etc . )
the proposed framework is composed of a total of five layers , including the application service layer , service support layer , network layer , perception support layer , and perception layer .
the application service layer offer a convenient user interface to patients , medical staff , and non - patients .
it is supplied with data and resources from the service support layer based on requests by the service . in each of the service applications , independent service with reinforced security exists .
the service support layer manages data and resources which serve as the basis for the efficient performance of the application service layer .
it takes the data transmitted by the perception support layer and stores it in an integrated database through the second access controller .
the service mgr ( service management ) , data mgr ( data management ) , resource mgr ( resource management ) , and system clock manage and supply service , data , resource , and time data regarding the application service . the a_en / decryptor encrypts ( or decrypts ) the data received from the a_communicator .
the a_communicator receives the data from the p_communicator , and then the data is forwarded to the second access controller ( or a_en / decryptor ) .
it handles direct and indirect data communication between the service support layer and perception support layer .
the perception support layer collects the data received from the perception layer and controls bad data and unauthorized access .
after that , it performs pretreatment to ensure that the data collected from different types of devices and sensors can be used appropriately .
the p_encryptor encrypts the data received from the classifier , and the p_communicator sends the data that was received from the p_encryptor and classifier . the perception layer is the domain in which the device ( or sensor ) that creates data exists .
various types of data created in this layer are transmitted to the perception support layer . in the next section ,
we focus on the perception side layer and application side layers , which are the core territories of remote medical services with iot , in adding each network elements to propose framework , which will be separated into two sections , namely , the a - n section and n - p section , in the explanation .
the n - p section refers to the perception support layer , perception layer , and network layer , while the a - n section refers to the application service layer , service support layer , and network layer .
the a - n section of the proposed framework includes parts that perform important functions , including management of the application service layer and supplying data and resource , and thorough access control should be conducted regarding this .
access control is handled by the contextual - based access control ( cbac ) technique , which is based on time and spatial data and takes timely and migratory characteristics of the subject of control into consideration , as well as role - based access control ( rbac ) , which allows flexible control in accordance with a complex environment and group .
authentication by cbac : uses cbac , which is a technique that controls access through contextual information . it verifies whether the confirmed timely - spatial information and system standard time value are within the permitted range ( min : minimum value , max : maximum value ) .
if the result is true , access validity is decided after verification that the scanned access location is within the permitted location range .
 authentication by rbac : in this stage , rbac is used , which controls access via role information .
limited to access with first round of authentication complete , the access profile of the service access attempter and previously registered access profile stored into db , are checked for consistency .
if the result is true , the role is verified to check whether the requested role is an authorized role in deciding the second round of authentication .
the n - p section is the part that handles device and sensor access as well as preprocessing , classification , and processing of the data received from it , and security measures during data processing should be available .
security during data processing uses data authentication , encryption , and security channel of reliable device .
.  authentication of device : valid devices are identified by comparing the initially verified device i d and device i d with authorized access . in the case of a valid device , the device i d and the current time from the device ( sensor ) and collection gateway are put through exclusive - or .
then , based on the created value , each of the created otp values is compared in completion of the final first authentication .
in the proposed framework , for secure and prompt processing of various types of health data obtained from sensors and devices , the data is processed separately in classification stages , including preprocessing in a secure mode that processes it into an appropriate form for processing and an actual processing stage .
preprocessing : this stage divides the data into efficient data processing units and removes mixed in data that exceeds the range or is not permitted , prior to processing . in this stage ,
 classification : security mode application usage is determined regarding data that has had unnecessary raw data and error values removed and separated into efficient processing units . the units are distributed into secure mode and normal mode with applied security processing in accordance with the mode value for each hardware i d defined in preprocessing .  processing : if general data without security application is processed , it is classified into normal mode , which applies the general processing method , and secure mode , which selectively applies security measures , including authentication , encryption , security channel , etc . , in situations requiring security .
next , we describe how the data classified into secure mode for the purposes of secure processing of data are processed .
table 6 shows an example that defines whether or not the security elements are applied to authentication , secure channel , data encryption regarding received data from applicable devices and sensors after the security mode has been determined for each device and sensor . as shown in figure 4
, secure mode applies the security element in accordance with security level ( 1 - 3 ) .
then , data encryption / decryption and secure channel are selectively applied , following the user definition .
the applied method uses each hardware i d and application mode , encryption and security channel application execution of hardware i d and secure mode table as reference in processing . 
authentication ( essential ) : authentication , which is the process of verifying the validity of a user , blocks unauthorized access regarding important data or personal data that should kept confidential through authentication of data classified as secure mode .
 data encryption / decryption ( optional ) : by encrypting the data with a mathematically verified symmetric key encryption and algorithm , it prevents plaintext exposure of transmitted sensitive data .
if the encrypted data was modulated during transmission , data integrity can also be verified because decoding is not possible .
 secure channel ( optional ) : during network transmission between two points , an asymmetric key encryption algorithm and electronic signature should be used to prevent exposure of transmission status and transmission data by composing a security channel ( virtual network ) during the connection of a separate sender and receiver in cases of data requiring stronger security .
the a - n section of the proposed framework includes parts that perform important functions , including management of the application service layer and supplying data and resource , and thorough access control should be conducted regarding this .
access control is handled by the contextual - based access control ( cbac ) technique , which is based on time and spatial data and takes timely and migratory characteristics of the subject of control into consideration , as well as role - based access control ( rbac ) , which allows flexible control in accordance with a complex environment and group .
authentication by cbac : uses cbac , which is a technique that controls access through contextual information . it verifies whether the confirmed timely - spatial information and system standard time value are within the permitted range ( min : minimum value , max : maximum value ) .
if the result is true , access validity is decided after verification that the scanned access location is within the permitted location range .
authentication by rbac : in this stage , rbac is used , which controls access via role information .
limited to access with first round of authentication complete , the access profile of the service access attempter and previously registered access profile stored into db , are checked for consistency .
if the result is true , the role is verified to check whether the requested role is an authorized role in deciding the second round of authentication .
the n - p section is the part that handles device and sensor access as well as preprocessing , classification , and processing of the data received from it , and security measures during data processing should be available .
security during data processing uses data authentication , encryption , and security channel of reliable device .
.  authentication of device : valid devices are identified by comparing the initially verified device i d and device i d with authorized access . in the case of a valid device , the device i d and the current time from the device ( sensor ) and collection gateway are put through exclusive - or .
then , based on the created value , each of the created otp values is compared in completion of the final first authentication . the device authentication process is shown in table 5 . in the proposed framework , for secure and prompt processing of various types of health data obtained from sensors and devices ,
the data is processed separately in classification stages , including preprocessing in a secure mode that processes it into an appropriate form for processing and an actual processing stage .
preprocessing : this stage divides the data into efficient data processing units and removes mixed in data that exceeds the range or is not permitted , prior to processing . in this stage ,
 classification : security mode application usage is determined regarding data that has had unnecessary raw data and error values removed and separated into efficient processing units . the units are distributed into secure mode and normal mode with applied security processing in accordance with the mode value for each hardware i d defined in preprocessing .
 processing : if general data without security application is processed , it is classified into normal mode , which applies the general processing method , and secure mode , which selectively applies security measures , including authentication , encryption , security channel , etc . , in situations requiring security .
next , we describe how the data classified into secure mode for the purposes of secure processing of data are processed .
table 6 shows an example that defines whether or not the security elements are applied to authentication , secure channel , data encryption regarding received data from applicable devices and sensors after the security mode has been determined for each device and sensor . as shown in figure 4
, secure mode applies the security element in accordance with security level ( 1 - 3 ) .
then , data encryption / decryption and secure channel are selectively applied , following the user definition .
the applied method uses each hardware i d and application mode , encryption and security channel application execution of hardware i d and secure mode table as reference in processing .  authentication ( essential ) : authentication , which is the process of verifying the validity of a user , blocks unauthorized access regarding important data or personal data that should kept confidential through authentication of data classified as secure mode .
 data encryption / decryption ( optional ) : by encrypting the data with a mathematically verified symmetric key encryption and algorithm , it prevents plaintext exposure of transmitted sensitive data .
if the encrypted data was modulated during transmission , data integrity can also be verified because decoding is not possible .  secure channel ( optional ) : during network transmission between two points , an asymmetric key encryption algorithm and electronic signature should be used to prevent exposure of transmission status and transmission data by composing a security channel ( virtual network ) during the connection of a separate sender and receiver in cases of data requiring stronger security .
here , we present a medical service scenario in which a secure remote medical service is provided in the iot environment with proposed framework application .
table 7 defines the medical service - oriented terms and figure 5 displays a diagram based on the proposed framework .
whether security technology is applied to each of stages - is explained in relation to the process .
 transfer of perception data : verify through da between device ( or sensor)-device ( or sensor ) , device ( or sensor)-collection gateway , and transmit data securely through sc , ded during data transmission .
 the collected data transferring and preprocessing from device ( or sensor ) : after completing da on the collection gateway , cbac and rbac should be applied to transmit the collected data . if additional security is required , ded and sc should be used because they make it possible to provide strong security service . , transferred data update and access to electronic medical records : the ua used when accessing the electronic medical records of the medical staff and others , including ded , sc , cbac , and rbac are shown in . , providing the services to users : da is used when device and sensor transmit data from the user ( non - patient , patient ) . on the other hand , when the user wishes to access a service , the ua is used .
the application of cbac and rbac is required during data transmission between user - service ; sc and ded are selectively provided for stronger security .
excluding survey - type theses from the previous research considered , four studies that took confidentiality , integrity , availability , and privacy into consideration were used in conducting a comparative analysis against the proposed framework .
the comparative analysis of the proposed framework was conducted with the security element as the standard , which was the selection standard of the previous research and previous studies .
 confidentiality : the proposed framework provides confidentiality via device- and user - based authentication and status- and role - based access control and security channel , encryption , etc . , for the purpose of confidentiality between device ( or sensor ) , device ( or sensor)-collection gateway , service and user .
mentioned the network structure and secure transmission regarding health information exchange via verified encryption and hash algorithm .
li et al .   mainly focused on secure patient - oriented personal health record access and efficient key management .
suggested maintaining confidentiality via an adaptive management model and focused on the role of security metrics .
tested authentication and authorization in the iot healthcare environment through a certificate - based dtls handshake protocol - based structure and proposed a technology for ip confidentiality in the iot environment .
 integrity : if an integrity verification measure is not available during data transmission and reception , there is a concern about too much data modulation ; this is particularly important in the case of medical data .
accordingly , to guarantee integrity , it should be possible to check for data modulation in each section . in the proposed structure
, the integrity of transmitted and received data in each section is guaranteed through the first and second authentication .
proposed an encryption and hash algorithm for network - focused health information exchange ; verification is not performed in each section .
in addition , as there is no mention of non - repudiation , it is difficult to ensure accountability regarding medical care .
li et al .   attempted to prevent access to unauthorized self - health information and to ensure accountability regarding data access . in savola et al .
, role metrics on access control exists ; however , there is no specific mention about that method of access control .
 availability : the framework proposed in this paper makes it possible to selectively apply encryption and a security channel that excludes authentication in each section , in providing confidentiality and integrity ; thus , flexibly securing availability is possible . the framework proposed by zaidan et al .   was designed only taking confidentiality and integrity into consideration .
the method proposed by li et al .   raises a concern because it can decrease availability in an environment where large amounts of data are obtained from various types of devices and sensors .
proposed availability metrics that include various elements , such as qos , resilience , scalability , etc . , but there is no specific mention about details .
is structurally dispersed in key management and is comparatively more secure than the state of the art centralized delegation - based structure ; therefore , it is more secure from availability attack . 
privacy : the proposed framework decreases the exposure of sensitive information compared to other studies by applying a security channel and encryption during the transmission of sensitive information between network sections .
also , privacy is made more secure by only allowing personnel with authorized roles to access data within the permitted time regarding specific medical staff and by applying ua , cbac , rbac during emr access by the medical staff .
discussed privacy protection through privacy metrics , but they did not suggest a specific method .
excluding survey - type theses from the previous research considered , four studies that took confidentiality , integrity , availability , and privacy into consideration were used in conducting a comparative analysis against the proposed framework .
the comparative analysis of the proposed framework was conducted with the security element as the standard , which was the selection standard of the previous research and previous studies .
 confidentiality : the proposed framework provides confidentiality via device- and user - based authentication and status- and role - based access control and security channel , encryption , etc . , for the purpose of confidentiality between device ( or sensor ) , device ( or sensor)-collection gateway , service and user .
mentioned the network structure and secure transmission regarding health information exchange via verified encryption and hash algorithm .
li et al .   mainly focused on secure patient - oriented personal health record access and efficient key management .
suggested maintaining confidentiality via an adaptive management model and focused on the role of security metrics .
tested authentication and authorization in the iot healthcare environment through a certificate - based dtls handshake protocol - based structure and proposed a technology for ip confidentiality in the iot environment .
 integrity : if an integrity verification measure is not available during data transmission and reception , there is a concern about too much data modulation ; this is particularly important in the case of medical data .
accordingly , to guarantee integrity , it should be possible to check for data modulation in each section . in the proposed structure
, the integrity of transmitted and received data in each section is guaranteed through the first and second authentication .
proposed an encryption and hash algorithm for network - focused health information exchange ; verification is not performed in each section .
in addition , as there is no mention of non - repudiation , it is difficult to ensure accountability regarding medical care .
li et al .   attempted to prevent access to unauthorized self - health information and to ensure accountability regarding data access . in savola et al .
, role metrics on access control exists ; however , there is no specific mention about that method of access control .
 availability : the framework proposed in this paper makes it possible to selectively apply encryption and a security channel that excludes authentication in each section , in providing confidentiality and integrity ; thus , flexibly securing availability is possible . the framework proposed by zaidan et al .   was designed only taking confidentiality and integrity into consideration .
the method proposed by li et al .   raises a concern because it can decrease availability in an environment where large amounts of data are obtained from various types of devices and sensors .
proposed availability metrics that include various elements , such as qos , resilience , scalability , etc . , but there is no specific mention about details .
is structurally dispersed in key management and is comparatively more secure than the state of the art centralized delegation - based structure ; therefore , it is more secure from availability attack . 
privacy : the proposed framework decreases the exposure of sensitive information compared to other studies by applying a security channel and encryption during the transmission of sensitive information between network sections .
also , privacy is made more secure by only allowing personnel with authorized roles to access data within the permitted time regarding specific medical staff and by applying ua , cbac , rbac during emr access by the medical staff .
discussed privacy protection through privacy metrics , but they did not suggest a specific method .
utilizing the databases of pubmed , springer , ieee , science - direct , bmc thesis , ' remote medical ' and ' iot ' were searched under the and condition , and ' telehealth ' , ' mobile health ' , ' telemedicine ' were each searched under a combination of or condition .
as a result , approximately 1,200 papers were searched , and among these , a total of 30 were extracted based on a standard of abstract containing security elements . as with the security threats classified in table 1 , the searched papers were classified into device ( or sensor ) , infrastructure , and service for discussion of the previous research in each category .
 device ( included sensor ) : doukas et al .   described digital certificates and pki data encryption based on a gateway for aggregation of health sensor data and to resolve security problems . hsu and pan   proposed agent - based telemedicine based on a p2p networking architecture .
explained the main security goals for the next generation of implantable medical devices and analyzed the most relevant protection mechanisms .
it focuses on protection of shared data 's collection and lost / stolen device 's data .  infrastructure : saleem et al .  
propose a framework for security based on ieee 802.15.4 . also , in , the security vulnerabilities and major attacks in the context of wireless body area network ( wban ) were identified .
zhang and zhang   introduced a secure and flexible platform based on iot and cloud computing that uses short - distant ambient communication protocols for medical purposes .
chen et al .   proposed an enhanced authentication scheme that overcomes the weaknesses inherent in khan et al .
's scheme , and they demonstrated that their scheme is more secure and robust for use in a telecare medical information system .
al ameen et al .   described security and privacy issues in wban , and they proposed measures for healthcare application in wban .
focused on a multiple data owner scenario and divided the users in the phr system into multiple security domains .
jiang et al .   proposed a secure and efficient authentication scheme with user privacy preservation which is practical for a telecare medical information system .
das and goswami   proposed a robust remote user authentication scheme for connected health care that preserves uniqueness and anonymity .
kim and lee   proposed cryptanalysis that discourages any use of the two schemes under investigation in practice , and they revealed some subtleties and challenges in designing this type of scheme .
das and goswami   proposed a novel and secure biometric - based remote user authentication scheme to withstand the security flaw found in awasthi - srivastava scheme and enhanced the features required for an idle user authentication scheme .
is more secure than a state - of - the - art centralized delegation - based architecture because it uses a more secure key management scheme between sensor nodes and the smart gateway .
proposed their secure framework for health information transmission within a central cloud - based model .  service for remote medical : savola et al .  
proposed adaptive security management mechanism based on security metrics . and they described protection methods of confidentiality , integrity , availability in ehealth iot application .
shin   introduced a framework for secure remote health - monitoring systems using a realistic risk model for sensor - data quality .
abie and balasingham   described a risk - based adaptive security framework for iots in ehealth that estimates and predicts risk damages and future benefits using game theory and context - awareness techniques .
the framework proposed by al - haj and amer   is implemented on a block - level of the partitioned - image for integrity , thus enabling the localized detection of tampered regions . in table 9 , the searched papers were first classified into device , infrastructure , and service .
then , they were sorted according to how they include the main security elements , such as confidentiality , integrity , availability , and privacy in understanding the characteristics and tendency of previous researches related to remote medical security . in the infrastructure field , it is evident that many studies took various security elements into consideration .
however , it is evident that there has been less research in this area than in the device and service fields .
accordingly , there is a need to reflect various security elements in all domains of service , infrastructure , and device .
as the demands and expectations regarding medical services are increasing , various new medical services are being introduced .
in particular , there is much interest regarding possible medical activities via remote medical services from long distance , and this is being combined with the new concept of the iot .
however , security element support has remained weak , with security being impossible in some cases or only partial security elements being provided regarding the modification of existing services and the creation of new service . accordingly
, remote medical security in the iot environment requires a new structure and method to prevent various threats directly connected to the safety of patients ' lives .
this paper proposed a service - oriented security framework for remote medical services in the iot environment .
the proposed framework is a service - oriented structure that can support dynamic security elements in accordance with demands regarding various types of new remote medical services that will be created in the iot environment , which will soon be realized .
it enables the provision of secure services that guarantee confidentiality , integrity , and availability for all , including patients , non - patients , and medical staff .
security elements are realized via role- and situation - based access control , user access control , data encryption , and the provision of a security channel . in future studies
, we will conduct an in - depth study regarding techniques that can satisfy demands in accordance with key generation and management .
in addition , we plan to enhance the efficiency and availability of the authentication method in the iot remote medical environment .
utilizing the databases of pubmed , springer , ieee , science - direct , bmc thesis , ' remote medical ' and ' iot ' were searched under the and condition , and ' telehealth ' , ' mobile health ' , ' telemedicine ' were each searched under a combination of or condition .
as a result , approximately 1,200 papers were searched , and among these , a total of 30 were extracted based on a standard of abstract containing security elements . as with the security threats classified in table 1 , the searched papers were classified into device ( or sensor ) , infrastructure , and service for discussion of the previous research in each category .
 device ( included sensor ) : doukas et al .   described digital certificates and pki data encryption based on a gateway for aggregation of health sensor data and to resolve security problems . hsu and pan   proposed agent - based telemedicine based on a p2p networking architecture .
explained the main security goals for the next generation of implantable medical devices and analyzed the most relevant protection mechanisms .
it focuses on protection of shared data 's collection and lost / stolen device 's data .  infrastructure : saleem et al .  
propose a framework for security based on ieee 802.15.4 . also , in , the security vulnerabilities and major attacks in the context of wireless body area network ( wban ) were identified .
zhang and zhang   introduced a secure and flexible platform based on iot and cloud computing that uses short - distant ambient communication protocols for medical purposes .
chen et al .   proposed an enhanced authentication scheme that overcomes the weaknesses inherent in khan et al .
's scheme , and they demonstrated that their scheme is more secure and robust for use in a telecare medical information system .
al ameen et al .   described security and privacy issues in wban , and they proposed measures for healthcare application in wban .
focused on a multiple data owner scenario and divided the users in the phr system into multiple security domains .
jiang et al .   proposed a secure and efficient authentication scheme with user privacy preservation which is practical for a telecare medical information system .
das and goswami   proposed a robust remote user authentication scheme for connected health care that preserves uniqueness and anonymity .
kim and lee   proposed cryptanalysis that discourages any use of the two schemes under investigation in practice , and they revealed some subtleties and challenges in designing this type of scheme .
das and goswami   proposed a novel and secure biometric - based remote user authentication scheme to withstand the security flaw found in awasthi - srivastava scheme and enhanced the features required for an idle user authentication scheme .
is more secure than a state - of - the - art centralized delegation - based architecture because it uses a more secure key management scheme between sensor nodes and the smart gateway .
proposed their secure framework for health information transmission within a central cloud - based model .  service for remote medical : savola et al .  
proposed adaptive security management mechanism based on security metrics . and they described protection methods of confidentiality , integrity , availability in ehealth iot application .
shin   introduced a framework for secure remote health - monitoring systems using a realistic risk model for sensor - data quality .
abie and balasingham   described a risk - based adaptive security framework for iots in ehealth that estimates and predicts risk damages and future benefits using game theory and context - awareness techniques .
the framework proposed by al - haj and amer   is implemented on a block - level of the partitioned - image for integrity , thus enabling the localized detection of tampered regions . in table 9 , the searched papers were first classified into device , infrastructure , and service .
then , they were sorted according to how they include the main security elements , such as confidentiality , integrity , availability , and privacy in understanding the characteristics and tendency of previous researches related to remote medical security . in the infrastructure field , it is evident that many studies took various security elements into consideration .
however , it is evident that there has been less research in this area than in the device and service fields .
accordingly , there is a need to reflect various security elements in all domains of service , infrastructure , and device .
as the demands and expectations regarding medical services are increasing , various new medical services are being introduced . in particular , there is much interest regarding possible medical activities via remote medical services from long distance , and this is being combined with the new concept of the iot .
however , security element support has remained weak , with security being impossible in some cases or only partial security elements being provided regarding the modification of existing services and the creation of new service .
accordingly , remote medical security in the iot environment requires a new structure and method to prevent various threats directly connected to the safety of patients ' lives .
this paper proposed a service - oriented security framework for remote medical services in the iot environment .
the proposed framework is a service - oriented structure that can support dynamic security elements in accordance with demands regarding various types of new remote medical services that will be created in the iot environment , which will soon be realized .
it enables the provision of secure services that guarantee confidentiality , integrity , and availability for all , including patients , non - patients , and medical staff .
security elements are realized via role- and situation - based access control , user access control , data encryption , and the provision of a security channel . in future studies
, we will conduct an in - depth study regarding techniques that can satisfy demands in accordance with key generation and management .
in addition , we plan to enhance the efficiency and availability of the authentication method in the iot remote medical environment .
 objectivesremote medical services have been expanding globally , and this is expansion is steadily increasing . 
 it has had many positive effects , including medical access convenience , timeliness of service , and cost reduction . the speed of research and development in remote medical technology has been gradually accelerating . 
 therefore , it is expected to expand to enable various high - tech information and communications technology ( ict)-based remote medical services . 
 however , the current state lacks an appropriate security framework that can resolve security issues centered on the internet of things ( iot ) environment that will be utilized significantly in telemedicine.methodsthis study developed a medical service - oriented frame work for secure remote medical services , possessing flexibility regarding new service and security elements through its service - oriented structure . 
 first , the common architecture of remote medical services is defined . 
 next medical - oriented secu rity threats and requirements within the iot environment are identified . 
 finally , we propose a " service - oriented security frame work for remote medical services " based on previous work and requirements for secure remote medical services in the iot.resultsthe proposed framework is a secure framework based on service - oriented cases in the medical environment . 
 a com parative analysis focusing on the security elements ( confidentiality , integrity , availability , privacy ) was conducted , and the analysis results demonstrate the security of the proposed framework for remote medical services with iot.conclusionsthe proposed framework is service - oriented structure . 
 it can support dynamic security elements in accordance with demands related to new remote medical services which will be diversely generated in the iot environment . 
 we anticipate that it will enable secure services to be provided that can guarantee confidentiality , integrity , and availability for all , including patients , non - patients , and medical staff . 