1 Introduction

The existence of life on this planet depends on a few factors among them are air, food, medication, etc. Medication or health care has its inception since the primitive ages and was one of the most critical elements, which have been taken care of. There implies plenty of improvements in the way medication is delivered since the time of its inception. The recent improvement and current age of modernization have revolutionized many fields ranging from defense, communication, services, etc. and each improvement setting its own benchmark. Every service which we avail has tried to make the life of human as easy as possible. Health care is also a stream, which has seen a drastic change in the way it was earlier and how it is now. Now, an attempt is made to provide each of these services available remotely and provide the same experience with many additional benefits. It comes bundled together in the name of TMIS (Telecare Medical Information System).

TMIS consists the services such as remote diagnosis, electronic medical records, etc. Remote diagnosis is the latest service, which is extremely useful for carrying out the diagnosis from a distant location. It becomes very useful in emergencies situation and providing instant medication and support. Another milestone is EMR (an electronic medical record), which supports the remote diagnosis. The only requirement for the services is the connection with the network and authorization to access the same. TMIS architecture described in Fig. 1. Generally, the user getting authorized via biometric check, if its success then it makes access the service otherwise it is denied. The subsequent medical data capture been made via the sensors embedded in the device and update with the device, which is then encrypted and propagated across the channel and finally to the central storage. The records as per request are availed at the hospital’s end, and the details are accessed after decryption and then after that, the same is decrypted again and resent across the channel and the same is reflected in the central storage and the process goes on as a service.

Fig. 1
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TMIS workflow

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Each of these services addressed comprises handling of sensitive data for each individual, which needs to be kept secure from that of adversary. There are numerous other reasons to keep the records secure. To address the security, there should be a proper message hiding and encryption technique, which should be used such as ECC (Elliptic Curve Cryptography), RSA (Ron Rivest, Adi Shamir, and Len Adleman), biometrics embedding, etc. to ensure that the system remains secure. Every technique have their own pros and cons, which makes it vulnerable to attacks various kinds. The new technique, which enables security for the services should be capable enough to deal with the shortcomings of various probable attacks and make the system robust enough to combat the consequences of attack if the adversary managed to intercept the channel. At the same time, the techniques should be efficient on the front of computation and communication standards to make it feasible enough to keeping other constraints into consideration (Fig. 1).

1.1 Threat Model

For the sake of security, the scheme is proposed which would enable the secure transmission of information. However, the adversary always seeks an opportunity to make the attack and disrupt the smooth flow. There are few assumptions which are made before. There is no chance to seek or snoop information transmission in the reliable channel. Attempt to break one-way hash function always leads to failure. Adversary has the freedom to access monitor the data over the unreliable channel on which there would be an attempt to access transmission details. So, the protocol should be in a form that no adversary should be entertained and the transmission should be attack resistant.

1.2 Bio-hash Function

A hash function is a one-way transformation function. The hash function accepts an arbitrary length input and produces a fixed length string, which is called a hash value or a message digest.

Due to uniqueness characteristic and ability of biometric, various systems use biometric as an adopted method to solve authentication and verification problems. However, a small change in biometric data may result in a massive change in the hash value. In other words, the result of the hash function will be changed due to the slight differences in the input and recognition errors will occur from slight biometric changes. To address this problem, a bio-function system is designed and studied [1, 2]. The bio-hash function has the following properties:

  • Similar hash values are produced by the similar biometric information.

  • Similar hash values are not produced by the different biometric information.

  • Translation and rotation of the original biometric template should not have a substantial impact on hash values.

  • Partial biometric information should be matched if sufficient detailed matters are present.

The hash function’s certain class can be formulated to be everlasting to the order in which the input pattern is presented to the hash function, and such hash functions are referred to as the bio-hash function. So, the bio-hash function can solve the recognition error of general hash function and can authenticate a legitimate user even if the user’s biometric information slightly change.

1.3 Contribution

In 2015, Mishra et al. [3] proposed an improved user authentication protocol for TMIS. They claimed that their scheme has the following merits: (i) efficient login phase and password change phase, (ii) Achieve user anonymity, (iii) Provide mutual authentication and Session key agreement, and (iv) Performance comparison with other similar schemes. We have pointed out several security weaknesses in Mishra et al.’s scheme such as Designing Imperfection in login phase, Designing Imperfection in authentication phase, Designing Imperfection in password change phase, Lack of biometric update or change phase, Strong replay attack, and Clock synchronization problem. The performance comparison of the other schemes is also made with which other protocols provide the overview about the respective protocol’s feasibility. We even propose the future scope, which the field of security.

1.4 Organization of This Article

The chapter has been in the organized in the following manner. In Sect. 2, the details about the related literature work is discussed, which describes about the similar works and their respective contribution in the domain. The next Sect. 3 details about the Mishra et al.’s [3] scheme and summary of each phase involved in the scheme. Section 4 details about the cryptanalysis of the scheme and pointed out the flaws present in the scheme. Section 5 brings the performance comparison of scheme with the latest protocols based on the parameter as storage cost, communication, and computation costs. We also address the future scope in Sect. 6 comprising of what the sector might hold. Finally, we arrive at the conclusion in Sect. 7.

2 Literature Review

The area of security is an active area of research and there has been numerous works in this area. After the first-ever authentication-based protocol was proposed in 1981 by Lamport [4] for which password was used for authentication. Many recent works have done in succession [3, 5,6,7,8,9,10,11,12,13] and few recent ones have been discussed here.

In 2015, Arshad et al. [5] brought an improvement to Bin Muhaya’s [14] scheme, which was found to be prone to offline password guessing attack and which even fails in providing the perfect forward secrecy. Improvement provided led to an improvement in computation time by 2.73 times. In 2016, Wazid et al. [15] brought a complete analysis of the security requirements keeping the services into consideration. The analysis provides the mathematical review of methods used along with their future scope of improvement that should be addressed in the near future. Also, Aslam et al. [16] in 2016 proposed a complete summary of the related scheme proposed based on one, two, and three factors with their respective pros and cons. It also points the probable attacks and mathematical requirements to implement these security measures. The analysis enables complete comparison based on features and respective drawbacks wrt to each proposed scheme is made.

Again in 2016, Jiang et al. [17] brought an enhancement to Wu et al. [18] proposed a protocol, which relies on 3-factor remote authentication and which found a vulnerability in offline password guessing, and at the same time prone to user impersonation attack. Additionally, it failed to provide a recovery mechanism if the smart card is lost or stolen. Another proposal was by Wazid et al. [19] which was again an improvement to Amin and Biswas [20] scheme of 2015 who proposed a 3-factor authentication scheme and which was found to be vulnerable to many potholes as privileged-insider attack, replay attack, along with user and server impersonation attack and even stolen smart card attack. Improvement addressed drawbacks and ensured that the scheme is shielded to attack as stated.

In 2017, Jiang et al. [21] brought an improvement to Lu et al. [22] scheme, which relies on 3-factor authentication scheme and claims to be secure from attacks but fails in identity guessing, tracking attack, identity revelation, offline password guessing, and impersonation attack with both user and server. The scheme makes improvements in the drawbacks addressed earlier at the same time making it a balance between security and efficiency. In 2017, again, Wu et al. [23] brought before RFID-based scheme, which enables both forward and backward untraceability. Also, it enables keeping the details of tag and reader anonymous. The scheme meets all the required security milestones and at the same time is applicable for usage across the services.

In 2017, authentication scheme which was based on human biometrics was brought by Jung et al. [24], which was an improvement to Liu et al.’s [25] proposed scheme in 2016, which used a biometric-based encryption scheme for health care but suffers numerous vulnerabilities as improper identification based on biometrics, spoofing attack and also fails to provide session key verification. The improvement provided by the protocol ensures that the system is secure with these loopholes mentioned in Liu et al. [25] scheme with security being enhanced. In 2017 again, Chatterjee et al. [26] provided an approach to carry out the authentication by setting the access control to the particular users as per requirement. It enables making group-based authentication scheme, which resists attacks and ensures data secrecy.

Another addition was by Mohit et al. [27] in 2017, which was an improvement to cloud-based Chiou et al.’s [28] scheme, which enables the patient and hospital to upload the data to the server which hereby could be used by the doctor for treatment and after further changes could be pushed to the server. It has its own flaw in the name of failing to preserve anonymity and safety against the stolen attack. The contribution of Mohit et al. [27] removes the drawback and improves communication and computation overheads.

In 2018, Kumar et al. [29] found that proposed Mohit et al.’s [27] protocol is a cloud-based system for mutual authentication in the domain of health care. It was found that the scheme has the drawbacks as stolen verifier attack, and many logged into the patient attack, impersonation attack, and failure for session key protection. These attacks are eradicated by Kumar et al. [29] and also improvement in computation and communication overheads. Again in 2018, Li et al. [30] brought before a cloud-based medical service where patients could securely use the service keeping privacy maintained. The scheme is even compared with protocols proposed earlier in a similar direction and proves that the scheme is shielded against the attack and provides a better computation, which makes the scheme practical for usage in cloud-based systems.

Table 1 Meaning of symbols and notations of this manuscript
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Table 2 Comparison of related works with cryptographic method, their highlights, and year of work
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3 Overview of Mishra et al. [3] Protocol

We have summarized Mishra et al.’s [3] scheme. It has phases as registration, login, verification, password change, and smart card revocation phase, respectively. The used notations here are addressed in Table 1.

For initializing the system, first, the server S makes a choice for two prime numbers i and j of length 1024 bits, it then calculates n = ij. Then select a prime p and integer X in the form that \(pX \equiv 1\bmod (i - 1)(j - 1)\). Where i, j, and X are kept as secret while n and p published as public.

3.1 Registration Phase

Here, whenever a new user makes registration. He/she performs the below mentioned steps (Table 2).

Step1::

The new user U makes a choice for identity ID and password PW with full liberty. Then, submit the request for registration to the medical server with ID.

Step2::

On receiving the request for registration by user U, S checks the uniqueness of ID. If it fails, then the session is aborted. Otherwise, allocates unique SC, it then calculates \(J = h(X\parallel ID\parallel N\parallel SC)\), where SC is the unique serial number of smart card and take N = 0 if user is new, else set N to N + 1.

Step3::

The S stores values as \(\{ J,n,e,h(.)\} \) in the smart card and sends smart card to user U. In addition, S keeps record of patient which is stored in the database and the new entry (ID, RID) is added in the database, where \(RID = (N\parallel SC\parallel {T_r})\) and \({T_r}\) is the time of registration.

Step4::

After the smart card is received, the user U gives biometrics B and calculates \(L = J \oplus h(ID\parallel PW)\) & \(V = h(ID\parallel H(B)\parallel PW)\), where H is a function which performs bio-hash. Then, swap the parameter L with J and then store the value V in the smart card. At the end, the smart card holds values as \(\{ V,L,n,e,h(.)\} \).

3.2 Login Phase

Here, whenever the user requires to avail the service, it logs into server, then insertion of smart card into a smart card reader and then the identity ID, password PW, and imprints biometric B as input.

Step1::

Check for \(V == h(ID\parallel H(B)\parallel PW)\). If this condition evaluates to false, the session is then aborted. Else, find \(J = L \oplus h(ID\parallel PW)\).

Step2::

Choose a random number \({r_u}\) and find \(A = {J^{{r_u}}}\bmod n\) & \({C_u} = h(ID\parallel A\parallel J\parallel {T_u})\), then put forwards the login message AID to the S, here and \(T_{u}\) is latest timestamp.

3.3 Verification Phase

Here, both server and user checks the legitimacy of one another and a session key is created for safe transmission of information. Following are the steps involved in verification phase.

Step1::

After receiving the message AID, the S calculates \(AI{D^X}\bmod n\) and gets \((ID\parallel {T_u}\parallel A\parallel {C_u})\). It takes out the entry \(RID = (N\parallel SC\parallel {T_r})\) which is equivalent to ID in the recorded table. Next, S checks if \({T_u} > {T_r}\). The S then calculates \(J = h(X\parallel ID\parallel N\parallel SC)\) and checks if \({C_u} =? h(ID\parallel A\parallel J\parallel {T_u})\). If it fails, the session is terminated. Else, U is identified by S. Furthermore, replacement of RID with \(RI{D^*} = (N\parallel SC\parallel {T_u})\) is made by S.

Step2::

The S makes a choice for random number \({r_s}\) and computes \(D = {J^{{r_s}}}\bmod n\), \({K_{us}} = {A^{{r_s}}}\bmod n = {J^{{r_u}{r_s}}}\bmod n\). It then calculates the session key \(s{k_{us}} = h(ID\parallel {K_{us}}\parallel J\parallel {T_u})\) and \({C_s} = h(ID\parallel s{k_{us}}\parallel D\parallel {T_u})\). At last, S assumes \(s{k_{us}}\) as session key and shares the message as \( < D,{C_s} > \) with user U.

Step3::

After the message is received, i.e., \( < D,{C_s} > \), the smart card calculates \({K_{su}} = D\bmod n = {J^{{r_s}{r_u}}}\bmod n\) and also the session key \(s{k_{su}} = h(ID\parallel {K_{su}}\parallel J\parallel {T_u})\) and also calculate \({C_{s}^{'}} = h(ID\parallel s{k_{su}}\parallel D\parallel {T_{u}})\). Now, check \({C_{s}^{'}} = ?{C_{s}}\). If this condition fails, then terminate the session. Else, S identified by U. Both U and S agree on session keys \(s{k_{us}}\) and \(s{k_{su}}\), i.e., \({K_{us}} = {J^{{r_s}{r_u}}}\bmod n = {J^{{r_u}{r_s}}}\bmod n\).

3.4 Password Change Phase

Here, the user is provided with facility to alter password without the aid of server.

Step1::

The user U now adds smart card in the reader and then gives biometric B. Again, input for ID, PW, and new password \(PW_{new}\) is made.

Step2::

The next smart card checks for \(V == h(ID\parallel H(B)\parallel PW)\). If this check fails then the session is terminated. Else, calculate \(J = L \oplus h(ID\parallel PW)\).

Step3::

Then, smart card calculates \({L_{new}} {=} J \oplus h(ID\parallel P{W_{new}})\) and \({V_{new}} {=} h(ID\parallel H(B)\parallel P{W_{new}})\). Replacement of L with \({L_{new}}\) and V with \({V_{new}}\) is made.

3.5 Smart Card Revocation Phase

Here, the revocation of smart card is made if the same is lost or damaged by any such reason. Then, the smart is provided by the seever when the request is made.

Step1::

The U makes a request to avail a new smart card to S along with an identity ID.

Step2::

The S checks for the identity of U. If the U is not genuine or if ID is invalid, the session is then aborted. Else, we head toward the very next step.

Step3::

The server S takes out \(RID = (N\parallel SC)\) which is similar to ID in stored database.

Step4::

S then frames the user specific smart card for U by storing the values \(\{ {J_{new}},n,e,h(.)\} \) in it, where \({J_{new}} = h(X\parallel ID\parallel N + 1\parallel S{C_{new}})\) and \(S{C_{new}}\) is new serial number of the smart card. Then, the smart card is sent to user U through a safe channel and replacement of RID with \(RI{D_{new}}\), where \(RI{D_{new}} = (N + 1\parallel S{C_{new}})\) is made.

Step5::

After gaining smart card, U performs Step4 of registration phase.

4 Cryptanalysis of Mishra et al. [3] Scheme

4.1 Designing Imperfection in Login Phase

In the phase of login, the verification of \(V == h(ID\parallel H(B)\parallel PW)\) will never be obtained because of the bio-hash function H(.) is not present in smart card’s memory. So, smart card reader cannot compute H(B). Therefore, without the correct value of H(B), the password verification, i.e., \(V = h(ID\parallel H(B)\parallel PW)\) always turns out to be false. Further, computation of \(J = L \oplus h(ID\parallel PW)\), \(A = {J^{{r_u}}}\bmod n\) & \({C_{u}} = h(ID\parallel A\parallel J\parallel {T_{u}})\) is done by smart card, which contains the value old identity and password. Therefore, the value of J, A, \(C_{u}\) is not correct without using proper value of identity and password. As a result, login message AID is incorrect. It is clear from the above explanation, Mishra et al.’s [3] scheme fails to verify identity, password, and biometric. This is a very severe drawback in Mishra et al. [3] scheme.

4.2 Designing Imperfection in Authentication Phase

In authentication, denial-of-service (DoS) attack can cause a permanent error on authentication by introducing unexpected data during the procedures of authentication. User U fails to login into the server using valid identity and password owing to the flaw in the authentication phase. This implies that inefficiency in the authentication phase would result in denial-of-service attack. An adversary may perform denial-of-service attack to cause the server to reject the login of a specific user. In Mishra et al.’s [3] protocol, the authentication phase has some design flaws, which is described as follows.

Step1::

Let’s suppose that user has lost smart card in some way. The user now wants to make the recovery of smart card then the user executes the smart card revocation phase.

Step2::

After successful execution of smart card revocation phase, \(RID = (N\parallel SC\parallel {T_{r}})\) is replaces with \(RI{D_{new}} = (N + 1\parallel S{C_{new}})\) and stores \(RI{D_{new}}\) into the database.

Step3::

In the next login session, the user shares the request for login via message \(AID = {(ID\parallel {T_u}\parallel A\parallel {C_u})^e}\bmod n\) to the server, where \({T_{u}}\) is the current login time stamp.

Step4::

After the message is received from user, the server in the beginning checks for the novelty of timestamp \({T_u} > {T_r}\). After execution of the phase of revocation, the timestamp \({T_r}\) is not stored in the database. So, the server cannot retrieve the timestamp \({T_r}\). Therefore, the server fails to verify the uniqueness of the timestamp and the session is aborted.

4.3 Designing Imperfection in Password Change Phase

In Mishra et al.’s [3] protocol, the same signs of imperfection was found in password change phase as in that of login phase. In password change phase also, the verification is a failure because the bio-hash function is not present in the smart card. So, the reader always fails in verifying the password, identity, and biometrics as well. As a result, inefficient password change phase results in denial-of-service attack. Denial-of-service attack is a decisive attack, where the adversary can use some methods to work upon the server so that the legitimate user’s access requests will be denied by the server. An attacker can modify the false verification information of a valid user for the next login phase. Afterward, the valid user will not access the server anymore. So, any illegal person could make changes in the user’s password in the following manner.

Step 1::

If attacker gains the smart card of user by some method and attempts to change the password of user.

Step 2::

He/she then enters a random identity, password, and gives biometric B. After that, reader performs the verification but we know that this password verification always fails. So, a user U is re quested to give a new password \(P{W_{new}}\).

Step 3::

Attacker enters new password \(P{W_{new}}\) and smart card calculates \({L_{new}} = L \oplus h(ID\parallel PW) \oplus h(ID\parallel P{W_{new}})\) and \({V_{new}} = h(ID\parallel H(B)\parallel P{W_{new}})\). Then, replace its L with \(L_{new}\) and V with \(V_{new}\).

Step 4::

So, the attacker could change the legal user’s password and after that legitimate user would not able to access his/her own account. The above discussion shows that the Mishra et al.’s [3] scheme has an inefficient phase of password, which also leads to DoS attack.

4.4 Lack of Biometric Update or Change Phase

The biometrics update requires because the biometrics has the problem of the aged deterioration. The most prominent properties in a authentication scheme using biometrics is that a legitimate user should be provided with the opportunity to change or update old password along with biometrics. Mishra et al.’s [3] scheme fails to provide biometric update or change phase.

4.5 Strong Replay Attack

In this attack, an attacker tries to be a legal user by retransmitting the previous executed messages to the desire entity. In Mishra et al.’s [3] protocol, in log-in phase, message \(AID = {(ID\parallel {T_u}\parallel A\parallel {C_u})^e}\bmod n\) is calculated on the patient’s end and transmission of this message is made to the server across the public channel, where \(A = {J^{{r_u}}}\bmod n\) and \({C_u} = h(ID\parallel A\parallel J\parallel {T_u})\), where ID is patient’s identity and \({T_u}\) is current timestamp. It can be shown that Mishra et al. [3] protocol is susceptible to strong replay attack due to following reasons.

Step1::

Suppose that the login message AID has intercepted by the attacker and retransmits after a short duration of time.

Step2::

Upon obtaining the message from the attacker, the server first decrypts the message AID using the secret key d and retrieves \((ID\parallel {T_u}\parallel A\parallel {C_u})\). Subsequently, server checks the novelty of time interval, i.e., \({T_u} > {T_r}\). But \({T_r}\) does not exist in the database because in the previous user’s authentication session, \(T_{r}\) is replaced with \(T_{u}\). Therefore, the condition \({T_u} > {T_r}\) never obtained and server fails to check the originality of the timestamp.

Step3::

Afterward, server calculates \(J = h(X\parallel ID\parallel N\parallel SC)\) and checks if \({C_u} = h(ID\parallel A\parallel J\parallel {T_u})\) and this condition always holds because AID is a valid message given by the genuine user. Therefore, the adversary is successful to login into the remote server using the previously intercepted message AID.

4.6 Clock Synchronization Problem

Any mutual authentication scheme is avoided from attacks as replay and man in middle with the help of timestamps. Unfortunately, clock synchronization problem [24, 26] arises using timestamp in huge networks like wide area networks, mobile communication, and satellite communication networks. The number of schemes depend on timestamp can resist replay attack by means of systems’s timestamp provided the system clock must be synchronized; otherwise, the scheme will not work accurately. Through the network environments and transmission delay is not predictable, the possible replay attack is found in all the existing schemes those used timestamp.

According to the aforementioned explanation, Mishra et al. [3] scheme depends on timestamps. Definitely, it would face the clock synchronization problem.

5 Performance Comparison

To measure the feasibility of the protocol, it is mandatory to analyze the performance in the form of required storage requirement, communication cost, and computation cost. For comparison, a series of protocols in the related domain is taken as represented in Table 3 below.

Table 3 Representation of protocols
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Table 4 Comparison of various cost with other protocols
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In Table 4 below, the comparison of the protocol with their respective costs are made. For memory requirement analysis, standards assumed are IDs and timestamps taking 32 bits, random nonce of 64 bits, one-way hash function requiring 256 bits, bio-hash function requiring 160 bits, elliptic curve point consumes 320-bits, and for encryption or decryption, it requires 512 bits. In the comparison of the storage requirements, the cost comprises of storage in database and smart card if protocol makes use of it. Taking protocol P1, the storage requirement in database is of {IDi, ni = 96 bits} and for smart card storage, it requires {Vi, Ki, xP, l, h(.), H(.) = 832 bits}. Again, in the similar fashion, the storage requirement for the protocols P2, P3, P4, P5, P6, and P7 are {704 = (256 * 2 + 32 + 160), 672 = (160 * 3 + 32), 1248 = (256 * 3 + 160 * 3), 1216 = (512 + 256 * 2 + 64 * 3), 1280 = (512 * 2 + 256), and 1440 = (256 * 4 + 160 + 512)} bits, respectively.

Again, on the communication front, the requirement is because of the messages shared across the channel to achieve mutual authentication among the participants. Taking protocol P1 messages shared are M1{dsP = 320 bits}, M2{AIDi, M1, M2} = 832 bits, and M3 {M3 = 256 bits}. Collectively comprising of 1408 bits. Similarly, for P2, P3, P4, P5, P6, and P7 requirement is of {1344, 1442, 1696, 2464, 2240, 2496} bits, respectively.

For calculation of computation cost, the timing requirement for each operation is considered. The operations as hash function, symmetric key encryption, point multiplication, point addition, fuzzy extraction, modular exponentiation, inverse, and bio hashing represented by {TH,TS,TPM,TPA,TFE, TME, TINV, TBH} whose operation time and corresponding values are (0.0005, 0.0087, 0.063075, 0.000262, 0.063075, 0.522, 0.003725, 0.02 s), respectively. Taking protocol P1, the operations being performed are 16TH,4TBH, 6TPM, and 1 TTINV which sums up the entire timing requirement to {16 * 0.0005 + 4 * 0.02 + 6 * 0.063075 + 0.003725 = 0.470175 s}. Similarly, for P2, P3, P4, P5, P6, and P7 requirement is of {0.2613, 0.338645, 0.38695, 0.35499, 0.5519, 0.351975} sec, respectively.

The graphical representation in Fig. 2 below shows the comparison of the protocol when their respective costs is made.

Fig. 2
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Storage cost, communication cost, and time comparison chart

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Now, in Table 5 below, the feature comparsion of the protocols is been made with the features which one protocol provides and the other fails to address. The properties such as Mutual authentication, Non-repudiation, User anonymity, Perfect forward secrecy, Biometrics protection, and attacks as Man in middle, Impersonation, Replay attack, Offline password guessing, and Denial of service are considered here.

Table 5 Feature comparison of protocols
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6 Future Scope

There has been a series of modifications in the protocol itself after the first protocol by Lamport [4] was proposed. The changes have come in the name of factors used ranging from passwords, smart card, and biometrics. They have been successful in providing the security from the numerous attacks but in the upcoming scenario, there have to be some added ways to tackle the security issues. In the future scope, there could be an increase in the biometrics being used for authentication say multiple biometrics. The next scope could be in the name of usage wearable devices which could provide the authentication thus eradicating the use of passwords and ID for authentication. The improvement could be even in the name of usage of hashing function and its implementation which could reduce the computation time as well as the number bits involved. The dependency on any such equipment as the smart card and its reader should be reduced taking into account the capacity of the system to be fault tolerant with smart card and even the server as well.

7 Conclusion

In this work, E-health care domain is addressed with its security implications and taking into account the protocol given by Mishra et al. The overview of the protocol is addressed and a lot of security loopholes in the protocol for respective phases and also prone to some attacks. The security comparison of the similar protocols has been made so that the analysis of the feasibility of the same could be made. There has been a discussion on the scope in the domain of security and with that of added feature and characteristics, which could be utilized to come up with the feasible yet dealing with all the loopholes which could erupt in the time to come.