I n the field of symmetricstreamcipher RC4 is the most popular algorithm that is immune to attack . It used variable key size for ciphering with byte-oriented operation. A number of research activities have been done to analyze the RC4 algorithm [2-8]. Some of these papers mentioned the weaknesses present in the algorithm [2-4]. Recent trend is towards the designing of hardware architecture on RC4 [9-11]. Claude Shannon proved a necessary condition for a symmetric key ciphering scheme to be unconditionally secure is that H(K) ≥ H(M), where H() denotes the entropy function while random variables K and M respectively denoting the secrete key and plaintext message . In cryptography the one-time pad is an unconditionally secure algorithm, but it has a drawback that key should be as long as the message. The ciphering that uses pseudorandom algorithm does not offer unconditional security, but it may provide computational security. In the field of electronic communication, encryption of message is very necessary to hide the meaning of information from unauthorized user. And the objective of encryption process is to make the message randomized so that it would be difficult to find out the meaning of the message. In symmetricstream ciphers generally the exclusive XOR operation is performed between the plain text and a key generated stream. The strength of a cipher depends on how much random key stream is produced by the key scheduling algorithm. More random key stream would produce more random cipher by encryption. There is many Pseudo Random Bit Generator (PRBG) and Pseudo Random Number Generator (PRNG) in literatures. It is well known that Blum Blum Shub (BBS) generator is a cryptographically secured PRBG to provide pseudorandom bit stream [1,13]. But it is considered as a slower algorithm as it produce only single
employed similar key for the encryption and decryption of a message. Encryption and decryption keys are keeping secret and only known by authorized sender and recipient who want to communicate. The allocation of different keys to the different parties increases the overall message security. The strength of the symmetric key encryption is depending on the secrecy of encryption and decryption keys. The symmetric encryption algorithms can be classified into block and streamcipher on This paper was partly sponsored by the Centre for Graduate Studies UTHM (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 8, No. 11, 2017 334 | P a g e www.ijacsa.thesai.org the basis of the grouping of message bits , . In a block cipher, a group of messages characters of a fixed size (a block) is encrypted all at once and sent to the receiver. Moreover, the block cipher can be further divided into binary and non-binary block cipherbased on the final results of the message, keys and ciphertext. The message bit size for the binary block cipher is 64, 128, 192, and 256 and the non-binary block cipher has not defined the standard that depends on the cipher implementation.
Our approach is novel and simple in the sense it does not utilize any complex mathematical equations in deriving its cryptographic keys for multilevel access controls. We designed and implemented a new database encryption scheme based on the block cipher built by Tuan Sabri (2000), which is referred to as TS Block Cipher throughout this paper. Our database encryption scheme is highly suitable and easily implemented in any commercial relational DBMS such as Oracle" and SQL Server". The scheme guarantees the integrity of data in the database, and provides data confidentiality accessible only by authorized database users with appropriate cryptographic keys. This multilevel database encryption scheme is based on symmetric cryptography which means that the key used to decrypt is the same as the one used to encrypt it. All users' cryptographic keys are securely stored in smartcards external to the database management systems and are read- in during the encryption and decryption process. In this process, users' cryptographic keys are utilized to generate on-the-fly "session keys" which are finally used to encrypt or decrypt the database data. The session keys, though are actually used in the encryption-decryption process, are just temporary keys and are not stored anywhere in the system. They are created, used, and destroyed. Before we describe fully the entire database encryption scheme, we introduce the basic concept involved in using TS Block Cipher as the main building block in the whole scheme. TS Block Cipher is used extensively in the scheme's cryptographic key derivatives and achieved the multilevel security requirements in the system. Unlike TS Block Cipher, TS Stream Ciphers are used only in the encryption and decryption of data in the database.
Fridrich  demonstrated the construction of a symmetric block encryption technique based on two- dimensional standard baker map. There are three basic steps in the method of Fridrich : (a) choose a chaotic map and generalize it by introducing some parameter, (b) discretize the chaotic map to a finite square lattice of points that represent pixels, (c) extend the discretized map to three-dimensions and further compose it with a simple diffusion mechanism. Further,
Abstract: - As our technologies are advancing day by day, there is always a requirement to modify and updates our existing algorithms accordingly. Whenever a word security comes, confidentiality of our secured data is always required. Many algorithms have been proposed to ensure this need, but there is always a competition to design an algorithm which should be better in some parameters to other. In this research, authors have studied many such algorithms and after deep study on that, proposed their own algorithm called which is better in terms of space, time and security. Authors also implemented and presented their result which shows its efficiency compare to other algorithms. Keywords - Encryption, decryption, plain text, cipher text, symmetric key and streamcipher.
In this paper, a streamcipherbasedsymmetric key cryptographic technique based on Chen prime number has been proposed. The proposed technique is suitable for encryption and decryption of a large number of files of almost any type. A symmetric key is formed by the sender directly from the plain text using Chen prime number. Then a symmetric key value is derived from the symmetric key which is used to form the cipher text. The symmetric key is sent to the receiver by the sender. The symmetric key value is derived by the receiver from the symmetric key which is used for decryption. To enhance security, focus is to secure the symmetric key value rather than the symmetric key.
Synchronous stream ciphers are symmetric cryptosystems which are suitable to encrypt message in communications protocols and can be used in hardware or software platforms. Rabbit streamcipher  proposed as finalist by ECRYPT, can be served for software application with synchronization purposes. For the first time, Ammuson in  showed a distinguish attack with 2 247 complexity due to a bias in keystream and this complexity was afterwards reduced to 2 136 by
Stream-ciphers represent an important class of encryption hardware that target applications with tight constraints on logic gates and memory or where high-throughput is necessary. For example, RFID tags are being used in a wide range of applications, many requiring secure transmission of identifying information and other data. Due to the tight limits on power and hardware resources, steam ciphers are attracting interest over the more complex block cipher designs for implementation in RFID tags. The stream ciphers process data one bit at a time. The bit size of the streamcipher is typically one bit or byte. The key size is longer or equal to the memory size. The stream ciphers are symmetric. A key challenge in the design of a good streamcipher is to balance an efficient hardware implementation while making it difficult for an adversary to decrypt the transmitted data. The main component of the streamcipher is the key stream generator, which can be viewed as a pseudo-random number generator (PRNG).
Data security is one of the challenges of all times. In the modern computer parlance it is important to secure the vital data. One of the common aspects of data security is the privacy for which Cryptography is the promising methodology. Cryptographic computations can be used in different concerned areas of computer communication for encrypting and transmitting the information. cryptography has shown its effectiveness in the field of secured data transmission and much research work is going on to make the computational process more complex to the unauthorized users so that they cannot decrypt the information in a reasonable time. In this research work, strong substitution based encryption algorithms are proposed and the encryption and decryption process are broadly divided into two rounds and key stream generating procedures are proposed. The proposed procedures are being implemented, analyzed and it shows its efficiency in computation, storage and transmission; and it is more powerful during the decryption process. Proper care has been taken so as to keep the cipher text output file size as close to the plain text file size for fast transmission and besides these the decryption time is more than the encryption time. This paper includes the procedures like Substituent list generation, key generation, encryption and decryption that are continued and enhanced from the previous proposed work . The performances are finally demonstrated and its implementations (using C # language) are explained and analyzed.
Encrypting sensitive data such as vehicle information on deduction standards could effectively resist some attacks on WSN. As secure key management is the premise of information encryption, encryption techniques and key management are the central gravity for the security of WSN. There has been extensive literature in researching WSN security, which can be divided into two categories in the cryptography field. One uses symmetric encryption; although existing symmetric encryption schemes provide a good level of security, key maintenance remains difficult. The other emphasizes asymmetric encryption (public-key cryptography). When asymmetric schemes are used, key management becomes easier, but they provide a lower level of security compared to the former. No matter which kind of protection method is adopted, the low battery power, limited memory space, and less processing capabilities of sensor nodes should be taken into account. In this study, we proposed an efficient symmetric key negotiation, data encryption and key update scheme based on a Logistic chaotic streamcipher algorithm.
optimization approach such as GAs is considered to improve the cryptanalysis problem, S. M. Hameed in her work used PSO to cryptanalysis transposition cipher, PSO used ciphertext only attack to recover the secret , H.A.M Al_Sharifi,in his research focused on using of PSO algorithm to cryptanalysis streamcipher using plaintext attack choosing one Linear Feedback Shift Register (LFSR) , B.N. Ferriman, in his Thesis focused on the RC4 algorithm and present a new approach for cryptanalysis of the cipher by attacking RC4s state register, Ali A. Abd in his research is considered a new approach to cryptanalysis streamcipher systems based on GA . The present work explores the related work done and applicability of GAs and PSOs in a field of cryptanalysis.
Feed-forward model is a basic pseudo random sequence generator (PRSG) using in streamcipher. A novel feed-forward model is constructed. Inversion attack on feed-forward model is analysed and detailed inversion attack algorithms and complexity of these algorithms are given, design advice on being resistant to inversion attack is presented on the basis of complexity analysis.The random attributions of the generated number are test with regards to period, balance, correlation and run property. And the result shows that the random number generator generates numbers with very good randomness.
Acknowledgments. This work is partially supported by Japan Science and Technol- ogy agency (JST), Strategic Japanese-Indian Cooperative Programme on Multidisci- plinary Research Field, which combines Information and Communications Technology with Other Fields, entitled ”Analysis of Cryptographic Algorithms and Evaluation on En- hancing Network Security Based on Mathematical Science.” The authors are grateful to three anonymous referees of ComSIS-2013 for improving this article.
T HE alleged RC4 streamcipher is the most widely used software streamcipher in different popular protocols. Apart from its popularity in the commercial uses, it has also become one of the most involved topics of research for cryptologists. RC4 only requires byte manipulations and hence it is ideal for software implementation. Its simplistic design allows faster encryption in software. Several years of thorough research on the cryptanalysis of the alleged RC4 showed many vulnerabilities and shortcomings of this streamcipher. In , a practical attack on broadcast RC4 was also demonstrated which was enough to compromise the security of many popular protocols which used the RC4 encryption scheme. As a result, many researchers tried to focus on designing RC4 like stream ciphers with introducing additional security layers to minimize the reported shortcomings of RC4. Many stream ciphers have been proposed by researchers to fulfill the objective. RC4A , GGHN , VMPC , etc. are such proposed stream ciphers to name a few. Nevertheless, all of the above mentioned stream ciphers have had some reports of distinguishing attacks – against them. In , a new streamcipher named RC4+ was introduced. It is a modified version of RC4 with a complex 3-phase key schedule and a more complex output function. The RC4+ streamcipher was primarily designed to over come the weaknesses and
ABSTRACT: The multiple outputs WG (MOWG) version is a new hardware design of the Welch–Gong (WG) cipher. Through signal reuse technique the proposed MOWG reduces the number of field multipliers and eliminating two inverters delay in the transformation. It accomplished by reconstructing the key and initial vector loading algorithm and feedback polynomial of the LFSR. And the MOWG transformation is modified with modular Montgomery multiplier based on the Montgomery multiplication algorithm. The Montgomery Multiplication algorithm is a standard arithmetic because it can perform modular multiplication without the trial division. It is the most efficient solution for the design of a fast architecture and VLSI implementation. The field programmable gate array implementation of this proposed design shows the area, delay and the power consumptions.
the concept of perfect security. In this paper, a novel image encryption algorithm based on logistic map is proposed, and it is demonstrated that a well-designed chaos-basedstreamcipher can be a good candidate and may even outperform the block cipher, on speed and security. In it, the keystream generator is based on coupled chaotic logistic maps that one logistic chaotic system generates the satisfied random number to update the parameter of the other. The chaotic binary sequence is perturbed by XOR operation on its own three parts. The encryption step proposed in the algorithm consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. Then, a detailed statistical analysis on the proposed encryption scheme is given. The experimental results based on coupled chaotic maps approve the effectiveness of the proposed method, and the coupled chaotic maps shows advantages of large key space and high-level security. Having a high throughput, the proposed system is ready to be applied in fast real time encryption applications.
symmetriccipher named, “YC1” that employs key spaces of varying lengths to encrypt and decrypt a plain text. Information Technology plays a very pivotal role in our businesses such as accomplishing complex tasks, speedy processing and many others but one very challenging concern today has to do with security in data communications. Data security in databases can be maintained by conventional methods even though malicious attackers can intercept the message or information and use them for ill-intentioned purposes. Therefore there is the need to effectively apply encryption and decryption techniques to enhance security in either stored data or data in transition. Cryptographic components are considered to be highly resistant to cryptanalysis if the right techniques or algorithms are employed.
In this paper, we have proposed a new unique lightweight block cipher SAL (Secure Advanced Lightweight) based on tiny compact s-box embedded with composite field arithmetic (CFA) technology to minimize hardware utilization on field-programmable gate array (FPGA) board. It takes input of 64-bit plaintext along with a key size of 64-bit extended to 128-bit using 14 and 16 rounds respectively. Moreover, the lightweight implementation of SAL shows enormous strength against various cryptanalytic attacks. The SAL encryption and decryption algorithm are useful for smart devices and power-constrained devices like the Internet of Things, Embedded devices and Radio frequency identification (RFID) tags.
At Crypto2008, the Cube Attack was introduced by Adi Shamir and his student as a known plaintext attack on symmetric primitives0. It is a major improvement over several previously published attacks of the same type, for example, Algebraic Initial Value Differential Attack (AIDA)0. In the key and public variables (plaintext or IV bits), if the output of cryptosystems can be represented by the polynomial
The mathematical functions used in the filtering WG7-NLFSR are the same as the functions used in the WG-7 streamcipher and the nonlinear WG permutation feedback does not increase any extra cost (as it is implemented for the key initialization), the implementation will be the same as the WG- 7 streamcipher. For details of the WG-7 streamcipher implementation, we refer the reader to . For easy reference, we reproduce the comparison of the implementations given in  in Table 8 in Appendix A, which indicates a microcontroller implementation comparison of the WG-7 streamcipher with other ciphers. The implementation includes the 4-bit MARC4 ATAM893-D microcontroller (a in Table 8) and the 8- bit AVR microcontroller ATmega8 (b in Table 8) from Atmel.