A Practical Quantum Public-Key Encryption Model Name: MuhammadAzeem Iqbal AwanClass: CS-7 (M)Roll no: BCS–F14-13 Submitted to:Ma’am Nadia Mumtaz Abstract:In this paper Quantum Public Key Encryption(QPKE) model is proposedby studying the related recent techniques of QPKE. This model is proposed suchthat changing in one module does not affect the whole model. Each module ofmodel is independent. The proposed model explicit stipulation on thegeneration, authentication, distribution and usage of secrets key.

Moreover, itencapsulates the process of encryption and decryption for users. Introduction:Practical model of quantum public key encryption (QPKE) issuggested by visualizing older QPKE schemes. The QPKE model consists of;1.Black box-D/E adapter2.

QPKDC-quantum publication key distribution center3. CA-certification authoritiesMethods:1.Quantum trapdoor one-way function (OWF):Consider a setZ which includes numbers and a set Q which includes quantum states of aphysical system.

Quantum OWF is a map i.e Z–›Q. It is easy to perform but itsinversion is difficult. If inversion of Z–›Q is possible with the help of sometrapdoor information than it is quantum trapdoor OWF.

2. The Holevo bound:Assume a party(Alice) prepares a domain px where x= 0,1, 2…, nAnd its probabilities are (p0, p1, p2,…, pn) respectively. Another party (Bob)Carry out a computation explained by POVM elements i.e{E4} ? {E0, E1, … En}on that states with their calculations their result is Y. The holevo boundmethod explains for such calculations that bob do; H (X: Y) ? S (?) – ?x px S(?x)Where P = ? px?x and S (?) ? -tr (? log ?)Represented by Von Neuman entropy of quantum state. This is veryuseful method to access information which plays important role in numerousprosecutions of quantum information theory.3.

Information theoretic security:It is a QPKEplan (E, G) for quantum memo. For every positive polynomial (P) and a large (n)any of two quantum memos ?, ? ? Hm satisfyD (?kpk?k(?), ?kpk?k(??))? 1/p(n)Where pk(?) and pk(??)are quantum ciphers of ? using QE algorithm and Pk is QPK and we take it as possibility of publickey pk generation fromquantum algorithm G and ? k=k pk =1. Left side of aboveequation is 1/p(n) in this p(n) is a random polynomial, we are unable to distinguishciphers by quantum orbit of any magnitude.Description of QPKE model:Symmetriccryptosystem i.e (one time pad) provides more introvert and arbitrary key whichis distributed between two groups.Recently, thisis done by quantum key distribution method. It offers solution to keyallocation issues in the phantom of congent opponents.

But key organization isthe main downside of symmetric encryption plan. A solution to this issue is theuse of uttered trusted third part or carol so that it behaves as a PKDC butdisadvantage of this is that PKDC becomes a striking objective.In this model PKDCis concerned only with public keys and private keys are under the control ofauthorized employs.

A more better solution to key allocation and handling issueis by the use of quantum public key asymmetric cryptosystem which has one way property.This one way feature is based on the basic rules of quantum mechanics. In QPKE authorizedusers uses arbitrary key to make public key which is related to private key. Inthis way multiple private keys are manufactured and are in the access of senderin the legal way i.e PKDC. 1.

Alice and Bob communicators get their verification from CA andobtain a data block of quartet (ID, CAID,skca,GenAlgsk).2. Customer shows GenAlgsk algorithm provided by CA with their own identity and get a rangeof private key pair (n,si) and n, si are unique arbitrarynumbers.3.

Customer selects any type of quantum one way trapdoor function F(.)And express it by si or (n.si) to get respective quantumpublic key.

4. Customer is registered with KDC for all the quantum public keysrelated to private key pair (n,si). Then PKDC connects to CA forverification and in case of verification register the customer.

5. For Alice to send data to Bob, Alice question for Bob’s ID to CAand if Bob’s ID is recovered and verified from CA (chip value ? holevo x) PKDC send quantum public keystate to Alice.6.

Alice code his data on his D/E adapter by quantum public key staterecommended by PKDC.Actual data is not in the form of simple memos but in theform of quantum domains.Ø After Bobreceive data from Alice,he enquire to CA center for Alice verification.Ø QUADRUPLEDESCRIPTION:1.(a) ID-user’s identification no.(b)CAID- user’s certificate(c) GenAlgsk- generator of private key(d) skCA- user’s private key.2.

Every D/E adapter can accomplish quantum state encryption anddecryption process and can also exhibit GenAlgsk for private keygeneration.3. For execution of authorized use of quantum public key thecustomer’s adapter will compute its Holevo bound as the total no.Of copiesissued by PKDC.4. To verify the validity of encrypted data received by receiver,both customer and PKDC have a buffet of beginning value of holevo x.whenPKDC sends a public key its buffet is decreased by one.

5. Thismodel can be used for point to point communication. DISCUSSION:The mainpurpose of an opponent wire tapper is to redeem the plain text from ciphertext. Opponent can only get information from public key when its multiplecopies are produced. So QPKE should analyze security issue related to size of publicand private keys.

Recently, it is shown that QPKE should have randomness for securecommunication. QPKE is also used as a black box to make new arbitrarybit-encryption plan.Focus of this model is;· Private key pair created by GenAlgsk should be random.· Quantum public key must be 1 to 1 or 1 to many.· CA is related to authentication and PKDC to control andpreservation of public keys.

· User can replace quantum trapdoor OWF and encryption/decryption atalgorithms at any interval.· CA and PKDC perform major role in this model. CONCLUSION: We purposed QPKE model by the integration of recent QPKEplans and older PKE theory.

Major part of model are CA,PKDC and customer’sencryption/decryption process(black box).private key creation occurs by meansof CA/customer. Quantum public key is generated by trapdoor OWF which iseffective and easy to measure. Recent work is on Blockchain technology whichcan replace CA and PKDC and solve decentralization issue but this is not nubileyet.