scholarly journals Novel Quantum Encryption Algorithm Based on Multiqubit Quantum Shift Register and Hill Cipher

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rifaat Zaidan Khalaf ◽  
Alharith Abdulkareem Abdullah

Based on a quantum shift register, a novel quantum block cryptographic algorithm that can be used to encrypt classical messages is proposed. The message is encoded and decoded by using a code generated by the quantum shift register. The security of this algorithm is analysed in detail. It is shown that, in the quantum block cryptographic algorithm, two keys can be used. One of them is the classical key that is used in the Hill cipher algorithm where Alice and Bob use the authenticated Diffie Hellman key exchange algorithm using the concept of digital signature for the authentication of the two communicating parties and so eliminate the man-in-the-middle attack. The other key is generated by the quantum shift register and used for the coding of the encryption message, where Alice and Bob share the key by using theBB84 protocol. The novel algorithm can prevent a quantum attack strategy as well as a classical attack strategy. The problem of key management is discussed and circuits for the encryption and the decryption are suggested.

Author(s):  
Matthias Wenzl ◽  
Daniel Kluka

Authenticating persons using fingerprints is a widely accepted method in the field of access control, border control, prosecution and many others. Today, fingerprint modules with customizable firmware can be bought commercially off the shelf by hobbyists and small companies to be used in their applications and are usually locally separated from a controller implementing the feature extraction and comparison algorithms. As a matter of fact, the communication channel between the sensor and the controller module is susceptible to eavesdropping and man in the middle attacks. Nevertheless, adding communication channel security to such a system has a direct negative impact on the system’s response time, thus directly affecting user acceptance. The aim of this paper is to provide a comprehensive investigation on measures to counter run-time degredation when adding communication channel security on behalf of an existing fingerprint verification chain. We show that a combination of the elliptic curve Diffie-Hellman key exchange together with AES-256 and the use of parallelization using OpenMP on a controller node leads to an acceptable run time making key creation and exchange upon every fingerprint read request a suitable undertaking.


2018 ◽  
Author(s):  
Andysah Putera Utama Siahaan

Computer security aims to help users prevent fraud or detect fraud in an information-based system. The information must be secured to be free from threats. Cryptographic techniques can prevent data theft. One cryptographic algorithm is Hill Cipher. This algorithm is one symmetric cryptography algorithm. The Hill Cipher algorithm uses an m x m sized matrix as the key to encryption and decryption. The fundamental matrix theory used in Hill Cipher is multiplication between matrices and inverses the matrix. Hill Cipher has two types of matrices in general, 2 x 2 and 3 x 3. This study discusses the order 2 x 2. The application of Hill Cipher in text-shaped media is highly recommended because it has fast encryption and decryption speeds. This method is very good at securing data that will be transmitted on an open network.


Author(s):  
Chuan-Kun Wu

In secure communications, key management is not as simple as metal key management which is supposed to be in a key ring or simply put in a pocket. Suppose Alice wants to transmit some confidential information to Bob over the public networks such as the Internet, Alice could simply encrypt the message using a known cipher such as AES, and then transmit the ciphertext to Bob. However, in order to enable Bob to decrypt the ciphertext to get the original message, in traditional cipher system, Bob needs to have the encryption key. How to let Alice securely and efficiently transmit the encryption key to Bob is a problem of key management. An intuitive approach would be to use a secure channel for the key transmission; this worked in earlier years, but is not a desirable solution in today’s electronic world. Since the invention of public key cryptography, the key management problem with respect to secret key transmission has been solved, which can either employ the Diffie-Hellman key agreement scheme or to use a public key cryptographic algorithm to encrypt the encryption key (which is often known as a session key). This approach is secure against passive attacks, but is vulnerable against active attacks (more precisely the man-in-the-middle attacks). So there must be a way to authenticate the identity of the communication entities. This leads to public key management where the public key infrastructure (PKI) is a typical set of practical protocols, and there is also a set of international standards about PKI. With respect to private key management, it is to prevent keys to be lost or stolen. To prevent a key from being lost, one way is to use the secret sharing, and another is to use the key escrow technique. Both aspects have many research outcomes and practical solutions. With respect to keys being stolen, another practical solution is to use a password to encrypt the key. Hence, there are many password-based security protocols in different applications. This chapter presents a comprehensive description about how each aspect of the key management works. Topics on key management covered by this chapter include key agreement, group-based key agreement and key distribution, the PKI mechanisms, secret sharing, key escrow, password associated key management, and key management in PGP and UMTS systems.


Author(s):  
Mirosław Kutyłowski ◽  
Piotr Syga ◽  
Moti Yung

AbstractIn this chapter we focus on two important security challenges that naturally emerge for large scale systems composed of cheap devices implementing only symmetric cryptographic algorithms. First, we consider threats due to poor or malicious implementations of protocols, which enable data to be leaked from the devices to an adversary. We present solutions based on a watchdog concept—a man-in-the-middle device that does not know the secrets of the communicating parties, but aims to destroy covert channels leaking secret information. Second, we deal with the problem of tracing devices by means of information exchanged while establishing a communication session. As solutions such as Diffie-Hellman key exchange are unavailable for such devices, implicit identity information might be transmitted in clear and thereby provide a perfect means for privacy violations. We show how to reduce such risks without retreating to asymmetric algorithms.


Author(s):  
Suresh Koduru ◽  
PVGD Prasad Reddy ◽  
Padala Preethi

<p>Today Internet of things (IoT) interconnects any object possessing sensing and computing capabilities to the internet. In this era, increasing number of electronic devices and applications in Internet of Things (IoT) requires secured communication with low power consumption capabilities. As security is a major challenge in internet of things, it is important to design a key management solution that considers resource constrained nodes and hence key management in public key cryptography is a crucial issue. In this paper, a novel key exchange algorithm was developed and implemented on a low powered “Raspberry pi machine” to realize the overall impact it creates on the device. The performance of the proposed algorithm had shown a great improvement over the popular Diffie Hellman key exchange algorithm and a two-level security for data exchange between the parties is implemented.</p>


2018 ◽  
Vol 10 (1) ◽  
pp. 147-160
Author(s):  
Amine Khaldi

Purpose – In a private key system, the major problem is the exchange of the key between the two parties. Diffie and Hellman have set up a way to share the key. However, this technique is not protected against a man-in-the-middle attack as the settings are not authenticated. The Diffie-Hellman key exchange requires the use of digital signature or creating a secure channel for data exchanging to avoid the man-in-the-middle attack. Methodology/approach/design – We present a Diffie-Hellman key exchange implementation using steganographied images. Using steganography made invisible the data exchange to a potential attacker. So, we will not need a digital signature or creating a secure channel to do our key exchange since only the two concerned parts are aware of this exchange. Findings – We generate a symmetric 128-bit key between two users without use of digital signature or secure channel. However, it works only on bitmap images, heavy images and sensitive to compression.


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