Category: CSE Project Reports

Cryptography:

Encryption is also referred as the cipher text; it is nothing but the process of converting some information into unreadable format to get protected from the unauthorized users. The text that is encrypted can be decrypted into readable format using a secret key. This process can also be referred as enciphering when the information is converted into unintelligible format using the translation tables and algorithms. The process of converting the information is also called as reversible translation. This cipher text which is converted into unreadable format is again re-converted into plain text to make it readable and this process is called as decryption or deciphering. Cryptographic systems are divided into symmetric key systems, in other words it is described as “the systems of cryptography are broadly classified into symmetric key systems”.

In a system if information is to be shared between the sender and the receiver then the process of encryption and decryption of the information is done by using a single key that known to both the sender and the receiver. The sender of the message uses the private key and the public key whereas the receiver uses the private key alone.

The process of encryption and decryption is done based on the algorithms and so appropriate algorithms are required for these processes.  The sender uses a key to encrypt a plain text into unreadable format or chipper text. Then the receiver should use the same key used by the sender to decrypt the encrypted text to convert into plain text again.

This process of encrypting and decrypting is done using an algorithm called “symmetric key crypto graphic algorithm”. The best examples for symmetric key encryption are blowfish and data encryption standard (DES). The encrypted public key algorithm in the conversion of plain text, in this process the sender uses the public key to encrypt the plain text into cipher text and that text when received by the receiver then a private key owned particularly is used to decrypt the cipher text into plain text. There are some examples for the public key encryption algorithms and they are Elliptic Curve Cryptograph (ECC) and RSA. Cryptography plays a major role in security issues of multicasting.

This Paper is written & submitted by Vamshidhar A.

QKD Design:

The following design is considered to implement the specific Quantum key distribution protocol.

Particularly this case study is classified in to three modules and the modules are as follows:

1. Sender:

1. Authentication of secret Key: A trusted center is trusted by the sender and that trusted center is given a secret key. Then the TC which is related to the sender will check the authentication of the secret key and the TC will not permit the user transmission unless the session key will be received from the TC.
2. Encryption: the session key received from the TC will encrypt the message and this encrypted message is also appended with the qubit. The transmission of data is completely done to the particular receiver.
3. Secret key verification: verification of the secret key should be done particular for the secret key received from the user, the particular and appropriate user must be authenticated for enabling the secure transmission of data.
4. Session key generation: Distribution of secret key is indicated as session key generation. The encryption and decryption process of a message utilizes the secret key distribution. These processes will be carried out by the session key using an 8 bit size. The random number with some exponential value and the random pseudo prime number produces a session key.
5. Qubit generation: At first the secret key must be converted into a hex-code and then it must be converted that hex-code into a binary to make it a random string. The quantum bits are taken as two binary values which are least bits and considered as 0 and 1. The combination of qubit and the session key is used to produce the quantum key, and the combination of qubits used are as follows:
   1.                                                   i.    If value = 1 and 1, then p[1].
   2.                                                  ii.    If value = 0 and 1, then p[0].
   3.                                                 iii.    If value = 1 and 0, then 1/√2(p[0]  – p[1]).
   4.                                                iv.    If value = 0 and 0, then 1/√2(p[0]  + p[1]).

2. Trusted Center:

              Hashing: The session key can be encrypted using a technique by utilizing the help of master key and that technique is called as Hashing. The TC storage stores the values of hashing.

1. Key distribution: If a sender needs to encrypt a message, then the qubit and the unique session key is shared by the sender. And when the receiver receives the encrypted message from the sender then the same session key and the qubit are shared by the particular receiver to decrypt the message.

3. Receiver Module:

             Secret key authentication: The receiver receives the encrypted message along with the hashed session key and qubit, and that qubit is verified and master key is obtained with the help of TC. The sender will hash the session key and that is reversed by the receiver for the authentication of that key.

1. Decryption: The receiver can read the encrypted message by decrypting the message which is made possible by utilizing a session key. 

This Paper is written & submitted by Vamshidhar A.

Analysis of the system and Design:

The Existing System of Quantum Key Distribution:

• Mechanisms and time stamps are necessary for escaping from the attacks. So to provide protecting from the attacks these time stamp or mechanisms are applicable to the key distribution protocol where three parties are involved.
• At least two communication rounds are necessary when the participants are connected with the challenge response mechanism along with the TC. The time stamp approach is sufficient in absorbing the assumptions of synchronization of clocks whereas it is not enough in distributed systems as the potential hostile networks and normal networks has a impulsive behavior which interrupts the distribution of keys.
• The existence of passive attacks cannot be identified by the Classical cryptography. The common passive attacks are such as the eavesdropping.

Limitations of Existing System:

There are limitations in using these explicit and implicit Quantum key distribution protocols 3AQKDP and 3AQKDPMA separately. And those limitations are:

• Identification of security threads in session key is not possible.
•  Identification of security threads in message is possible.
• Authentication is provided for the message. 

Proposed System of Secure Chat Program:

                         Quantum cryptography uses the Quantum mechanisms to take in the public discussions and sessions keys. Quantum key distribution protocols are also provided by the quantum cryptography. Quantum cryptography also enables verification of accuracy in session keys and also identifies the eavesdroppers in the communications. In public discussions in quantum cryptography, there is a necessity of qubits and additional communication rounds between the sender and receiver of the information. Quantum cryptography offers techniques that are capable of efficient key verification and suitable for authenticating the user. These techniques are also presented by the classical cryptography.

Quantum key Distribution Protocol there are of two types and they are:

• Proposed 3AQKDP
• The Proposed 3QKDPMA
  • Proposed 3AQKDP:

           The information of the 3AQKDP is represented by defining the notations and also with the help of the previous section. In the communication using this protocol TC must be distributed to all the participants as the secret key is imagined besides the TC.

• The Proposed 3QKDPMA

 3QKDPMA has two phases and they are:

• Setup phase
• Distribution phase
• Setup Phase

              In setup phase the secret key is shared previously by the users along with the TC. And in this phase the qubits are divided based on the secret key distribution that is done previously.

• Distribution Phase

               In the distribution phase the details how “A” and “B” use the help of TC to share the session key is known. This phase also explains the user authentication explicitly.

This Paper is written & submitted by Vamshidhar A.

In quantum key distribution systems there are three phases to establish a communication most securely. The three steps are as follows in this Paper Presentation:

• Key Agreement: In this phase the two parties that participate in the communication concurs a distributed private key which is secure.
• Authentication: In this phase few authentication forms are used to avoid the attacks on key agreements mainly the “main-in-the-middle” attacks. For this a message is sent from the specific explicit party.
• Key Usage: In this phase a secure key having the additional primitives or authentication is established using a cipher or a one-time pad for attaining encryption.

                               Quantum key distribution is just a part of the entire data security infrastructure which depends on the private key, this private key is concurred by the two parties that participates in the communication which is not based on the input of the protocol and also there are no computational assumptions for the security of private key to depend on. The authentication for the key agreement and the security in the infrastructure of public key for a long-term is achieved by using the public key cryptography and Quantum key distribution together as a combination.

A private channel is required by the QKD for establishing authentication for the key. For example public key cryptography is not employed securely any longer by using the trusted courier of the key that is traditional over a private channel. Comparing the quantum key distribution outputs the sessions keys are more than the required amount of communication that is private.  As the keys are distributed by the QKD over a private channel and the keys that are distributed are not dependent on each other, and this can be consider as an advantage in quantum cryptography. The compromised keying stuff can be affected by the future sessions when provided with security. The public key cryptography systems are retooled with freshly designed algorithms in the coming technology and these tools offers the basic security factors for the quantum key distribution. 

This Paper is written & submitted by Vamshidhar A.

A fiber optic QKD system is developed by using the optical fiber as a standard telecommunications and that QKD system is a short wavelength gigahertz clocked system which is useful for the quantum key distribution along a short distance metropolitan scale networks or metropolitan campus networks. Z.L.Yuan has achieved a quantum key distribution across a constant telecom fiber network of 122km distance. The photon that is entangled is directly distributed to the 7.8 km distanced receiver’s station particularly at night. In the year 2007, a QKD system was executed across an optic fiber network of 25km, this QKD system is a “reverse re-conciliated coherent-state continuous variable system.

A free space system or a QKD system based on entanglement is established over 144km network. Later in the year 2008, an entangled QKD system is established over a links of two free space optical fibers, nearly 1,575 m is separated completely by these links. T. Honjo et al has experimented on the QKD system based on primary entanglement across a 100 km distanced optical fiber network in the year 2008 itself. These White Paper experiments of various researchers have continued for the year 2009 also and in the year 2009, a QKD system based on the entangled state is established between the source and the destination over a network of a distance of 300 km and even in if in a more distanced networks.

                       All the above experiments of various researchers have proved that the usage of quantum cryptography and quantum communication is precise in real life applications. The fact is that earlier commercial quantum cryptographic device is offered for the application in real time. And so the QKD protocol is presented in the year 2004 along with the analysis of QKA protocol and its efficiency. In Quantum cryptography, most important and technical support is achieved by the quantum key distribution. QKD can be considered as the advanced tool for the cryptographers for making a secure key agreement using an un-trusted channel, which means QKD permits an channel that is un-trusted to make a secure key agreement. In quantum cryptography White Paper Presentation, the out is dependent on the input in using QKD and this is not possible in traditional cryptography. QKD is used build the systems using the designed security properties and so the additional cryptographic primitives like authentication are also existed in the system.

                     The additional primitives that are existed in quantum cryptography are quantum money, blind quantum computation, quantum coin tossing and quantum public key encryption; these primitives are designed by using the medium-to-large quantum computer. Many research groups has researched on the QKD systems and the implementations are done and considered as complex economically and so the usage of QKD will be high in the future security infrastructures. 

This Paper is written & submitted by Vamshidhar A.

QKD Introduction:

                  Quantum key distribution is a technique that uses the fundamental laws of quantum mechanics in order to achieve security key and also to ensure security. This QKD Security Seminar Report is also called as QKA that is the Quantum key Agreement. Generating a private key in more number between the two parties or among a public channel that is not secure is the main aim of QKD protocols. The single condition for the QKD protocols is the error rate must be less than the actual threshold then the information of the quantum will be communicated over a public channel. In order to enable secure communication between the authorized parties a resultant key is utilized, this is to establish a “conventional private key cryptosystem”.

                                The Seminar Report of Quantum key distribution is developed first by Bennett and Brassard in the year 1984 and that protocol is called as BB84 protocol. The development of QKD has extended to the free space systems and optical fiber system. In the year 2000, G.L Morgan has reported the use of QKD in a 48 km distanced optical fiber network. This is developed in a better way in the year 2002 by theUniversityofGeneva; this development is usage of QKD in the 67 km distanced of optical fiber network. This attempt was done successfully. In the year 2003, Guo’s group has developed a QKD in the 14.8 km special network of optical fiber, and this distance was expanded in a great range for the year 2004. Later it is also reported that in a 50 km optical fiber network. QKD can stay constant for six years.

The Zeng’s group has demonstrated a quantum communication practically in a local area network using the TCP protocol.  Japanese researchers have done many advanced researches and accomplished a single photon interference experiment for the quantum cryptographic system along 100km distance. This experiment is done using a balanced “gated-mode photon detector”. N.Gisen has developed solutions for the problems of chromatic dispersion using the constant fiber quantum channel along 30km distance for using the energy based entanglement based on the quantum key distribution. 

This Paper is written & submitted by Vamshidhar A.

Advantages of Quantum key distribution protocol is: 

• The main advantage of QKDP is it allows the detection of eavesdropping because the error level will be comparatively more when the eavesdropper connects to the quantum channel than the error level that occurs naturally. Along with the detecting of eavesdropping, quantum mechanics laws will also allows the process of setting the error level between the intercepted data in dependence. Unrestricted security is provided by the QKD protocols and during this process isolation extension is permitted at the same time quantity of data is decreased considering the key that can be interrupted by the Eavesdroppers.
• The other advantage of this protocols is the utilization of supreme key which is permitted by the additional encryption with the help of the traditional algorithms that are symmetric and known in the “quantum key distribution’s information theoretic security”. Therefore entire data security is increased by this QKDP. 

Disadvantages of quantum key distribution protocol:  

• The considerable disadvantage of QKDP is very high price for business-oriented QKD systems.
• Complete solution for the distribution of keys is not provided by the network release in the systems supported by the Quantum key distribution protocols.
• Weak coherent pulses are used instead of the single photon pulses for decreasing the effectiveness of protocol. Conversely controlling this technology may be compressed in future if the usage of these coherent pulses is continued.
• The transfer rate will be decreased immediately with the rise of channel length.
• As the key rate decreases there will be a problem of photon registration results.
• An error may occur by the photon during the data transmission due to the photon depolarization in quantum channel.
• Practical realization is difficult particularly in quantum systems at d-level in QKD protocols.

 This Paper is written & submitted by Vamshidhar A.

Quantum key distribution protocol (QKDP)

                                Quantum key distribution is a technology which depends on the quantum physics laws and this is used for the production and distribution of cipher keys that are secure into few unsecured channels. Here photon technology identifies the third parties or eavesdroppers who try for probable eavesdropping in the quantum channels, for this the technology uses quantum bit errors. If the information is encoded and sent randomly then the single photon produces the distributed keys that are secure and secret. The estimation of probabilistic character and state of photon are estimated by the help of these distributed secret keys. Quantum key distribution system has two channels called quantum channel and classical channel. Quantum channel is used in the quantum key distribution system for transmission of qubits or single photons along a transparent optical path. Whereas the classical channel is paired strongly with the quantum channel in order to gain timing requirements and this classical channel is also considered as the usual IP channel.

                            There is much variation between the quantum cryptography and traditional cryptography because of the reason that laws of physics are concentrated more in quantum cryptography.  Particularly the data transmission and data saving in the quantum cryptosystem are done by using the laws of physics. For example, in a electric optical fiber, when the transmission of polarized photon is done then a secret key is created with help of optical fiber which can be considered as an secure channel. This secret key is generated in the form of a bits string that is random. These bit strings that are random are used in quantum cryptography in the same way like the secret keys are used in traditional cryptography. At present, many protocols for quantum key distribution are implemented, and these protocols are known as the B92 protocol, EPR protocol and two states protocol etc. The first implemented QKDP (Quantum key distribution protocol is called as BB84 protocol, this is designed by Gilles Brassard and Charles Bennet, this protocol is the most used protocol even now a days.

                    If we consider an example with two communication parties A and B, let A be the sender and B be the receiver and let the third party or eavesdropper be E. In this case of Quantum key distribution, the unconditional secure key should be distributed between A and B by noticing the existence of E. The security of QKDP is ensured differently with the help of quantum mechanics principles when it is regarded with the comparison to usual distributed key techniques which relies on the estimation of calculations that are yet to be verified. In usual techniques while the information is transferring the third parties cannot gain the knowledge of the data transferred because they don’t posses required resource to perform computations.

This Paper is written & submitted by Vamshidhar A.

Advantages of Quantum Computing:

• The main advantage of quantum computing is it can execute any task very faster when compared to the classical computer, generally the atoms changes very faster in case of the traditional computing whereas in quantum computing it changes even more faster. But all the tasks can’t be done better by quantum computing when compared to traditional computer.
• In quantum computing qubit is the conventional superposition state and so there is an advantage of exponential speedup which is resulted by handle number of calculations. 
• The other advantage of quantum computing is even classical algorithm calculations are also performed easily which is similar to the classical computer. 

Disadvantages of Quantum Computing:

• The main disadvantage of computing is the technology required to implement a quantum computer is not available at present. The reason for this is the consistent electron is damaged as soon as it is affected by its environment and that electron is very much essential for the functioning of quantum computers.
• The research for this problem is still continuing the effort applied to identify a solution for this problem has no positive progress. 

This Paper is written & submitted by Vamshidhar A.

Quantum computing:

The Literature Review study area that concentrates on the implementation of quantum theory principles for developing the computer technology is called Quantum computing. The main focus here is given to clarify the nature and character of energy and matter on the level of quantum. There is a lot of development in the quantum computing from the last billion-fold area in increasing the capacity of quantum computer in the similar way how the development from abacus to today’s super computer.

                     Quantum computing can be understood by learning the quantum laws of physics by which so much of processing power is achieved and the capacity will be developed to several states and these will together helps in executing the tasks in terms of parallel attainable combinations. Generally quantum computing depends on quantum laws of physics because there are many advantages from the quantum physics atoms and nuclei properties which are definite, as the quantum physics laws and quantum computing are permitted by these properties to work mutually as quantum bits or simply as qubits, to be the processor or memory of a computer. The advantage of qubits is particular calculation are made faster exponentially when compared to the usual computers.

                      The computations on   usual binary characters is not the base for qubits always, because by using the usual computers the information is encoded using the binary characters particularly into bits is encoded into ‘1’ or ‘0’ and also the calculations for only one set of number can only done at a time. But in case of the quantum computers information is encoded into a series of quantum mechanical states like electrons in spin direction or arrangement of photon polarization which can also be represented with ‘0’ or ‘1’, or can also be represented as superposition of many numbers which are not similar and sometimes represented as a number that express the state of qubits represented among ‘1’ or ‘0’ anywhere or may also represented as orientation of both. 

This Paper is written & submitted by Vamshidhar A.