A Contemporary Study on Quantum-Computing Security Mechanisms in 5G Networks

5G communication technology works with the integration of several technologies viz. Cloud Computing, network partitioning and software based networks. This integration allows the communication between thousands of device across the world which have enormous issues related to data protection, data authenticity, and data confidentiality. So, there is an immense need of secure protocols to face or resolve security related issues related to design and operation of 5G network. Moreover, some structured cryptography protocols required to develop and accomplish data security in 5G communication. The study focussing on the comprehensive consequences of quantum computing on security implementations of 5G mobile communications. The study discussing about the cryptographic algorithm used in 5G, and what are the various consequences of involvement of quantum computing.

appear similar to that of input bits. Once the message is encrypted with the key, it will send to the receiver onto the public channel which might be vulnerable to eavesdropping attack. It is advisable to share the secret key information only over the very secure communication channel. The generated key firstly sent over the channel followed by the message. The major drawback of DES is it does not guarantee the complete security of the message.

Public Key Encryption
The previous encryption method involve in generation of separate key for every user which is a difficult task as number of keys increases with the increase in number of users. This is so because k users require k×(k-1)/2 number of keys and need to track the specific key of the specific user to whom he wants to communicate. Public key encryption method resolve this issue of generation multiple keys. Public key encryption also termed as asymmetric way to encrypt message as in this case user have to maintain only two keys i.e. a private key or a public key to encrypt or decrypt the message. The private key used by the sender of the message to encrypt it. The sender is free to announce public key as it partially involves in the process of encryption and decryption [48]. The receiver decrypt the message by combination of public and private key. Sender sends the message after encrypting with the public key and receiver decrypts the message with private key. This process also restricts sender to decrypt his own message. These methodologies are proved to be some mathematical operations are simpler to solve at one end not the other. As an example if someone wants to multiply two large prime numbers it proves easy as compared to finding the factors of the obtained results if sufficient resources are not available. First PKC i.e. RSA obtained the security mechanism from the fact that factorizing large numbers is very difficult to obtain. The major drawback of the conventional cryptographic techniques is the unavailability of the technique to detect eavesdropping.

One Time Pad Cryptosystem
This technique was evolved by Gilbert Vernam in 1917 and offers simple and effective solution to security. It is considered as the good cipher technique which ensures the accurate secrecy of the message. This cryptographic technique is based on sporadic keys set which can be written on paper sheets integrated to a pad. At receiving end receiver needs the pad similar to the sender end available for encryption and decryption purpose. The security mechanism implemented by OTP is inappropriate. The participants of the communication have to share the encoded message alongwith the secret key of same length. The key used to encrypt or decrypt the message can be utilized only once. This can be possible with the proper synchronized communication between sender and the receiver.

Quantum Cryptography:
The communication channel which implements quantum computing needs a pair of polarizing filter at both ends of the communication. For instance, the photographs at sender end can send by specific polarization so that it can be compared at the receiving end. Polarization filters can be implemented in rectilinear (vertical or horizontal orientation) or diagonal (45 and 135 degree orientation) of photons. Calcite crystal or two photomultiplier detectors capable to detect these two directions. In the event that the photon is on a level plane captivated it will be coordinated to upper channel and to vertical finder in the event that it is vertically energized. In the event that comparative contraption is turned at 45 it will record inclining bearings. Accordingly the turned contraption is futile for rectilinear bearing and vertical device for askew heading .henceforth we cannot quantify both at the same time consequently confirming Heisenberg vulnerability principle.BB84 Protocol was created by Charles H, Bennett of the IBM Thomas J. Watson Research Center and Gilles Brassard of the University of Montreal, quantum cryptography depends on the way that estimating a quantum framework, for example, a photon irreversibly changes its state and clears out data about the angles before estimation [1].

Quantum Computing effect on cryptography 2.1 Cryptanalysis
Yanofsky & Mannucci[2], suggest there will be a consequential impact on cryptography with the development of general-purpose highly-scalable quantum computer. Specifically, quantum algorithms are designed that affect both symmetric and asymmetric key cryptography algorithms. Shor [3], proposed an algorithm which affect asymmetric algorithm which is widely used even till now to maintain security. Alternatively Grover [4], proposed an algorithm which create lesser impact on security implementation of symmetric algorithm. Following are some points discussing the consequences of these algorithms on quantum computer which implemented them.
As per the contemporary key length, the problem of large calculations or computation of discrete logarithms is found to be insecure in the case of asymmetric cryptography techniques. Accordingly, the asymmetric techniques conceivably partitioned with the help of huge general-purpose quantum systems. Besides this, the increment in length of the key leads to secure current utilized techniques and will prove as good instead of using the algorithm infeasible to implement in many cases.
The key length of symmetric cryptography algorithms is apparently diminished. In case of quantum computer n-bits in a key of symmetric algorithm offers 2n/2 calculations where as in case of tradition computer systems the order was 2k. Moreover, in the case of quantum computing the calculations might be complex. Additionally, quantum attacks behave differently as compared with the traditional computer's attack like brute force. As per the traditional practices, it is unpredictable to find the quantum attacks complexity. As in the case of quantum computer 128-bit key provide same security level as that of 64-bit key which is quite low.

Security Consequences
It is intriguing to predict the future effect insecurity of cryptographic algorithms as in current use are rendered uncertain sooner or later. The algorithms that verifies the data integration and is valid for long-term, no consequential problems possible to identify until some new more secure algorithm developed till that time period. It is unsecure to store encrypted text(cyphertext) as when the some intruder crack encryption algorithm, the text can easily be decrypted to the original text(plaintext). Quantum computers has the capability to break the encryption algorithms, as its use made the existing encryption algorithms vulnerable. For instance if some data is encrypted using a key establishment technique and then the data travelled via unsecure communication channel, puts the data and key into risk by the availability of quantum computer.

Replacement Algorithms
As per the increase demand of security now a days, several organizations working together to design cryptographic standards which are better than previous. The security improvement in cryptographic field is possible only with the increase in key bits. Currently in symmetric key encryption 256-bit key is allowed used to encrypt data and is considered as powerful key. Although in case of asymmetric key encryption most of the algorithms are considered as insecure. Numerous organizations including ETSI, NIST, ISO/IEC working on the development of asymmetric key cryptography to secure data in the post-quantum era. Currently NIST organization built the effective Post-Quantum cryptography standard to secure data with asymmetric key cryptography [23].
In 2017, November, NIST commenced a procedure to engage, estimate and regulate different quantum-resistant asymmetric-key cryptography. In this procedure the primary stage requested public suggestions on minimum applicable requirements, submission specification, and estimation criteria for candidate algorithms. NIST revert back to these suggestions with the summary of the changes made to the algorithm standard. NIST received huge proposals for new algorithms, which it adopted according to the series of rounds as per the public suggestions and cryptanalysis.

Introduction to 5G Security
As compared with the growth of 4G networks, it was expected that 5G network will offer high QoS(Quality of Serives) [24]. It is visualized that 5G communication technology will offer high network bandwidth with reliable and fault tolerance capabilities to the users. IoT(Internet of Things) comes with the integration of 5G technology [25][26][27][28][29][30][31][32][33][34][35], with the connection capability of anything, anyplace, anytime, any communication technology or any services.
The use of Internet of Things (IoT) is growing rapidly and offers several solutions to every field. Some reports discussed that approximate to year 2020 there will be 75 billion IoT devices utilize among the humans across the world [11]. This gigantic growth needs some standard protocols and device architecture for service provisioning to IoT based devices. IoT device usually operates on battery and has limited computational capabilities with lesser storage capability. So, these devices are mainly responsible to capture real-time data and the processing as well as storage of the data is done possibly at some cloud server or fog server. As the data processing and storage is done on servers instead of IoT devices there is a need to implement security mechanisms onto the data so as to maintain security and relatability of obtained data. Some of the techniques to implement security on IoT devices includes, asymmetric cryptography (public key cryptography), symmetric cryptography (private key cryptography), and hash functions. Among these, public key cryptography is widely used in Internet based communication as it offers huge security mechanisms to email clients [12], websites [13], E-signature documents [14], E-Transactions [15], medical data [16], Enterprise Communication [17] and so on. Some of the algorithms of public key cryptography like ECC [19] [20], RSA [18], DH [21] gain more popularity and even are the part of Internet standard such as Transport Layer Security(TLS).
IoT networks includes the capability to interconnect with sensors, service providers, applications with the help of its integration with 5G networks. Mainly the 5G networks allows the integration of several networking technologies like, SDN, NFV, network slicing, cloud computing and so forth. These sort of integration leads to the development of security and privacy concerns to the 5G network. So, there is an intensive need to design secure network architectures for 5G networks to reduce security and privacy issues of the network [36][37][38][39]. The security mechanisms in 5G networks can be easily implemented with the use of quantum walks hash functions.

Post-Quantum Cryptography
This section is going to discuss various Post-Quantum Cryptography (PQC) and ciphers which increase the reliability of 5G communication network.

Quantum Impact on Cryptography
Shor [3], proposed an algorithm in 1994 which offers the efficient way to factor huge prime numbers on quantum computer reduces the security of RSA. Expansions discuss the trends to be utilized to beat discrete algorithms issues and subvert ECC ciphers. In 1996, Grover [8] proposed the symmetric key ciphers like AES can be exploited through quantum data structure.

Post-Quantum Ciphers (PQC)
PQC is having different components from the classical public key cryptography. In PQC no key agreement is available which works on the principle of Diffie-Hellman algorithm. So, there is no requirement of 1:1 correspondence of tradition ciphers to the PQC domain. This section discusses some of the PQC categories used to encrypt the data.

Lattice Cryptography:
Lattice is referred to the all integer set which is arranged as a linear group of basis vector set. The main problem in mathematics is the shortest vector problem which is used to observe non-zero vectors from the vector space which traverse with basis vector. Lattice cryptography is considered NP-hard type problem. NTRU(Nth Degree Truncated Polynomial Ring) is the most popular lattice based cryptography which is an open source and comes under the category of public key encryption techniques. NTRU have the features of encryption as well as signature formulation. Encryption task is performed using NTRUEncrypt algorithm while signature formulation is handled using NTRUSign algorithm. It performs the operation within the area of truncated polynomial ring. Moreover, its security not only based on the complexity of discrete log type problem solving, but also to cracking this technique is similar to solve shortest vector lattice problem. Although it is not completely implemented mathematically using lattice, but its security proof is similar as that of solution obtained from shorted vector problem. Hoffstein & Silverman [41], in their study proposed the technique NTRU in and this techniques undergoes several studies. All this way lots of issues identified in this and resolved over the years. There are several other techniques available which works on different principle and offers several benefits. The other techniques includes, GGH(Goldreich-Goldwasser-Halevi) [42], is based on closest vector problem while recent algorithm Bimodal lattice signature scheme(BLISS) is a message authenticity technique to identify the person who sent the data. Of these methodologies, a refreshed rendition of NTRU has been endorsed as IEEE Standard 1363.1 and ANSI standard X9.98.

Hash-Based Cryptography:
The ongoing danger of blockchain innovation has restored center around hash-based cryptography. In light of the Merkle has trees, this methodology can be utilized as an option in contrast to customary computerized marks. The eXtended Merkle Signature Scheme (XMSS) has been distributed as an instructive record by the IETF as RFC 8391.

Code-Based Cryptography.
Code-put together cryptography is based with respect to the trouble of interpreting a general straight code. The McEliece plot was presented in 1978 and depends on registering arbitrary straight changes of a mistake adjusting code's generator network, and just the private key holder knowing the variables of that framework [44]. The figure has been suggested for thought in a PQC domain, yet requires amazingly long key lengths [45]. There are a couple of other code-based plans, outstandingly Niederreiter's methodology that additionally bolsters computerized marks.

Supersingular Elliptic Curve Isogeny Cryptography.
While the figures examined so far offer reciprocals to encryption and mark conspires, a key understanding convention with forward mystery is prominently inadequate. In 2012, analysts demonstrated that supersingular elliptic bends and supersingular isogeny diagrams can be utilized to make a post-quantum Diffie-Hellman-type figure, yet these methodologies remain moderately beginning and unstudied in scholastic writing.

Conclusion
The primary component of 5G systems is that they will play a focal job in our day by day life. Besides, as they use many promising correspondence advancements and will bolster a colossal number of associated gadgets this will without a doubt bring huge difficulties for the trust, security and protection. In this manner, secure instruments also, conventions are required as the reason for 5G systems to address this issue and follow security-by-plan yet in addition security-by-activities rules. Enlivened by the confinements of the old style cryptosystems and the upsides of quantum strolls, in this paper we compares new developments of cryptosystems to accomplish secure data sharing and information assurance which are based on quantum advances. To begin with, two the study discussed post quantum cryptography and cryptographic ciphers instruments for 5G applications dependent on QWs, in particular. At that point, in view of the two hash work proposition, two productive security conventions for making sure about the information in 5G systems situation have been presented. Directed execution investigations and reenactment results demonstrated that the proposed approaches are portrayed with high security, proficiency, and heartiness against a few notable assaults which make them reasonable for use inside different 5G applications.