Abstract: PRINCE is a low-latency block cipher presented at ASIACRYPT 2012. The cipher was designed with a property called ?-reflection which reduces the definition of decryption with a given key to encryption with a different but related key determined by ?. In the design document, it was shown that PRINCE is secure against known attacks independently of the value of ?, and the design criteria for ? remained open. In this paper, we introduce new distinguishers on PRINCE-like ciphers by constructing probable or impossible relations from the cipher data located at layers that are symmetric around the middle of the cipher. We show that the probabilities of such relations, called reflection characteristics in this paper, depend crucially on the choice of the reflection parameter ?. Several classes of ? are investigated. As a result we show that there exist values of ? which, if used in the otherwise original PRINCE, would allow a key-recovery attack on the full 12-round cipher with the data complexity of 257.98 known plaintexts and the time complexity of 272.39 encryptions. While this attack is not better than the generic attack on the complete cipher, where the core cipher is protected by the whitening key, the same reflection distinguisher, when applied on the core cipher without the whitening key, yields a key-recovery attack with time complexity less than exhaustive key search and data complexity of 256.21 known plaintexts. As a result of the new cryptanalysis method presented in this paper, new design criteria concerning the selection of the value of ? for PRINCE-like ciphers are obtained.

Abstract: Steganography is an art of hiding the existence of secret information by embedding it in a cover and hence preventing the unauthorized access of confidential information. This paper proposes a novel approach of encrypting the plain text into cipher text and embedding it into a color image. Encryption is done in two stages, during first stage it is encrypted by Ceaser cipher technique and in the second stage it is encrypted based on chaos theory. The cipher text obtained after encryption is embedded using 3, 3, 2 LSB replacement algorithm.

Abstract: A permutation cipher is a very old form of cryptography. It works by moving letters around in a random pattern. In this paper we have implemented a new method of pseudorandom permutation. Along with this, a working algorithm has been provided that produces a block cipher using the mentioned procedure. The discussed algorithm operates on a file containing a stream of integers delimited by a space. The file is first converted to a two dimensional array. This array is randomly shuffled. Thereafter the encrypted cipher is obtained by recombining the keys with the shuffled array. For decryption, the cipher is again read into a two dimensional array. This time, the entire array is sub-divided into three parts. The first and the final part consist of the shuffled message. The second part consists of the keys. The elements of the shuffled array are then rearranged in accordance to the keys. The recombination results in retrieving the original file containing the stream of integers.

Abstract: The stream cipher Salsa20 and its reduced versions are among the fastest stream ciphers available today. However, Salsa20/7 is broken and Salsa20/12 is not as safe as before. Therefore, Salsa20 must completely perform all of the four rounds of encryption to achieve a good diffusion in order to resist the known attacks. In this paper, a new variant of Salsa20 that uses the chaos theory and that can achieve diffusion faster than the original Salsa20 is presented. The method has been tested and benchmarked with the original Salsa20 with a series of tests. Most of the tests show that the proposed chaotic Salsa of two rounds is faster than the original four rounds of Salsa20/4, but it offers the same diffusion level.

Abstract: The idea behind this paper describes a modality about secret interface over the globalization of the communication over the world. To accomplish this phenomenon, two varieties of security mechanism, cryptography and steganography is being applied. At the former stage, encryption is being provided to secret plain text using Vernam cipher (One-Time Pad) transposition technique, since Vernam cipher show good performance metrics in terms of less CPU running time, file size same after encryption and strong avalanche effect compare with all transposition cipher. And at the later stage, it transform cipher text into bytes and divides each byte into pairs of bits and assigns the decimal values to each pairs, which is known as master variable, master variable value range will be vary between 0 to 3. Depending upon the master patchy value, add that cipher text in the career image at Least Significant Bit (LSB) 6th and 7th bit location or 7th and 8th bit location or 7th and 6th or 8th and 7th bit location. Which shows the embedding location dynamicity of the algorithm depends upon dynamically changed master variable value. After completion of embedding and sending the stego image to the receiver side, retrieving process of the cipher text from the said locations will be done. And then decryption process to get the secret plain text back will be performed using the Vernam cipher transposition algorithms. In this we provide robust image steganography. Performance analysis observed using MSE and PSNR value.

Abstract: Recent developments in the resource constrained devices have led to a renewed interest in designing light-weight primitives with inventive and unconventional structures. Using round-dependent constants instead of a strong key schedule is one of the most widely used trick against the self-similarity cryptanalysis in recent cipher proposals. So far there has been little discussion about the effect of the round constants on the security of the ciphers. In this study, the authors identify several weaknesses in round-reduced versions of the block cipher ITUbee, which was presented recently at LightSec 2013. These weaknesses allow to build relations between the round constants. The author's technique leads to several cryptanalysis in the weak-key, related-key and single-key models and shows that the resistance of ITUbee against self-similarity cryptanalysis is not independent of the values of round constants. They show that the round-reduced cipher under a fraction of the keys is distinguishable from an ideal random permutation. Then they utilise a similar technique to show there exists a deterministic related-key differential distinguisher for up to eight rounds of the cipher. This observation leads to the decrease of the security of 8-round ITUbee in the single-key model by one bit.

Abstract: Music has a versatile dimensionality; it can be used to express feelings, emotions and can also be used as a communicable language. Music and its attributes have been used in cryptography and steganography from a long time. Musical symbols and notes are used as replacement/substitution cipher. Using music as a cipher or cover media not only enhances the security of the message but also reduces its chance to be detected as an encoded or ciphered message. This paper proposes a hybrid Polybius and Playfair cipher which encodes the message into sequence of musical notes. The Playfair key matrix is generated using the Blum-Blum Shub generator. The bigrams of plain text message is first encrypted using Playfair cipher then individual character of the encrypted message is re-encrypted using Polybius cipher. The Playfair cipher enhances the security of the encrypted message over the simple substitution technique. The Polybius cipher then reduces the character set by appropriate number of symbols (here musical notes) for replacement. The basic 5X5 structure of key matrix in Polybius and Playfair is extended to 10X10 to hold the 95 prinTable characters of ASCII character set.

Abstract: In recent years, a variety of encryption algorithms have been investigated to image cryptosystems. Most of them are based on permutation and diffusion architecture. These two procedures are independent according to the encryption algorithm. Block cipher and stream cipher can also be used to encrypt the image, the permutation can be different. This paper proposed the corresponding permutations based on block cipher and stream cipher.

Abstract: Researchers give an alternate method to the standard Friedman and Kasiski techniques for determining the length of a keyword in Vigenere-type ciphers using a comparison twist on the sorted frequency vectors of the letter usage in a message.

Abstract: The Vernam cipher, or one-time pad, plays an important role in cryptography because it is perfectly secure. In this cipher a key is a sequence of equiprobable independently generated symbols. We show that under small disturbance of these properties the obtained cipher is close to the Vernam cipher in the case where the enciphered plaintext and the key are generated by stationary ergodic sources.

Abstract: Secured communication of information is important across the globe. Cryptography is one of the methods to attain security of information. The Hill cipher (HC) is one of the famous and known symmetric encryption algorithm based on linear matrix transformation. Hill Cipher has several advantages such as masquerading letter frequencies of the plaintext and high throughput. Despite the ease and speed of the Hill Cipher, the original Hill Cipher is no longer used due to the vulnerability against known plaintext-ciphertext attack. So to enhance security of Hill cipher various methods are proposed by different researchers. This paper aims to present review of various techniques used for Hill Cipher modification to improve performance of Hill Cipher in data security.

Abstract: Nowadays security becomes an important feature with the growth of electronic communication systems. In this paper, we study the security problem and present a proposed triple hill cipher algorithm and its implementation on FPGA to encrypt any binary data such as images, audio, video… etc. This proposed algorithm uses three stages of a modified hill cipher to make the algorithm more robust, each stage is considered a block cipher with a block length of 128 bits and key length of 256 bits. The message to be encrypted is processed by this block cipher in three stages to increase the security. The keys are taken from random number generator. The proposed algorithm is promising to give better security.

Abstract: The algorithm presented in this paper computes a maximum probability differential characteristic in a Substitution-Permutation Network (or SPN). Such characteristics can be used to prove that a cipher is practically secure against differential cryptanalysis or on the contrary to build the most effective possible attack. Running in just a few second on 64 or 128-bit SPN, our algorithm is an important tool for both cryptanalists and designers of SPN.

Abstract: Playfair cipher is the form of block cipher which has no limit on the number of characters in a message it can do, but it operates on block of characters encrypting and decrypting two characters at a time cipher. In this, the plain text digrams are converted to cipher text digrams and vice versa using a pre-shared key. This is achieved by performing several operations column wise row wise and by creating rectangular form. Even so the traditional 5 x 5 Playfair cipher supports twenty five uppercase alphabets only. To overcome this drawback, various authors have proposed extended Playfair cipher. This paper deals with the study of these variations proposed by different authors on the basis of some parameters.

Abstract: The rapid development of technology influences the future of pervasive computing, which is characterized by the usage of smart devices with limited resources, such as computing power, memory or battery supply. To create pervasive applications, which meet real-time security needs, ciphers that are capable to run on devices with small computing power must be created. In this context, in the last few years, lightweight cryptography has been a hot research area and many impressive implementations and ciphers have been published. At ASIACRYPT’2012 conference a new lightweight block cipher, called PRINCE, was presented. After its appearance, the designers of the algorithm proposed a challenge for all cryptographers, which consist in finding practical attacks on round-reduced PRINCE cipher. In this article, we present various new attacks on round-reduced PRINCE and the time and data complexity necessary for each of them. The first attack which was successfully applied to 4, 5 and 6-rounds is the boomerang attack. We also describe a knownplaintext attack for 4 and 5-round PRINCE algorithm.

Abstract: Sablier is an authenticated cipher submitted by B Zhang et al to the CAESAR competition, which is composed of the encryption Sablier v1 and the authentication Au In this work we first present a state recovery attack against the encryption Sablier v1 with time complexity about 244 operations and data complexity about 24 of 16-bit key words, which is practical in a small workstation Based on the above attack, we further deduce a key recovery attack and a forgery attack against Sablier The results show that Sablier is far from the goal of its security design (80-bits security level)

Abstract: 3D-Playfair cipher is a multiple letter encryption cipher. Trigraphs (combination of 3 characters) of the plaintext are treated as single unit and converted into corresponding cipher text trigraphs and vice-versa. Classical Playfair Cipher supports English alphabets with limitation that only one alphabet “i” or “j” will be considered at a time. 3D-Playfair Cipher came into focus to eliminate this limitation. In addition to that 3D-Playfair Cipher also overlooks the limitation of similar fashion encryption of diagrams and its reverse diagrams. 3D-Playfair cipher supports all 26 English alphabets {A-Z}, 10 digits {0–9} and 28 special characters including { ! “ ∗ # $ % & ‘ +, − . / : ; ( ) ? @ [ ] \ ⁁ _ | }. The theme of this research is to enhance the security of text files that contains alphabets, numerals and special characters. In this approach we developed a structure rotation concept on key matrix of 3D-Playfair cipher using random key to achieve the objective. Random sequences are generated through Linear Feedback Shift Register due to its simplicity and better performance.

Abstract: Information Security has become an important issue in data communication. In modern world, internet and network applications are growing fast. So the importance and the value of the exchanged data over the internet or other media types are increasing. Any loss or threat to information can prove to be huge loss to the organization. Encryption technique is the best solution against the intruder. In this paper we formalize a new symmetric cryptographic cipher technique which is easy to understand and implement. This introduced cipher technique’s name is Cross Language Cipher technique (CLCT). In this technique we use the concept of cross language which plays an important role in data security. Today most of the cipher techniques work with English language but we use two languages English and Hindi in our cipher technique. Basically, here are two functions in CLCT; first replaces/converts the English text data to Hindi text data and second function encrypt the Hindi text data. The encryption function is similar to Caesar cipher’s function. To find the actual plaintext by intruder is not an easy task because CLCT uses diffusion property. So, CLCT is more reliable and powerful cipher technique. Most of cipher techniques have issue of higher performance and good security feature. Advantages of CLCT are that its performance is high and is less vulnerable to network attack.

Abstract: With increasing use of network applications, security has become a major issue. Strong encryption mechanisms are required for securing important data. This encryption is provided by a strong cipher, capable of producing strong and highly random sequence of pseudo-random numbers. Through this paper, we present a detailed study of existing LFSR (Linear Feedback Shift Register) based hardware ciphers and an experimental approach to implement A5/1 algorithm on hardware platform. From this detailed study a generic cipher compatible with various network applications like smart cards, mobile phones, wireless LAN etc. has been proposed.

Abstract: Cryptography is a technique which converts any intelligible message into unintelligible message; it is used for secure communication between any two parties in any insecure channel like internet. The Vigenere cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword. Vigenere is a simple form of polyalphabetic substitution and One Time Pad Cipher is the only existing mathematically unbreakable encryption (2). Research paper "EXTENDED VEGENERE CIPHER WITH TRANSPOSITION CIPHER", 2014 written by Anuja Priyam (1), proposed an extended Vigenere cipher in which encryption and decryption applied using 128 ASCII and 128 extended ASCII character with two keys. After message is encrypted by first key, transposition cipher is applied under certain order then adds some logical bits, now use second key for encryption and again apply transposition cipher, which gives more secure cipher text and vice- versa process applied in decryption part. This paper provides security in text field only but latest research said that there is an attack possible in key field also. To avoid this attack a secure approach is important in key field also. To avoid this problem a new approach is using i.e One Time Pad cipher. In proposed cipher, key is secured by one time pad cipher. In encryption part, message is encrypted by using One Time Pad Cipher, in which a random key is generated, this key is XOR with the message and the key length is equal to the message length. After message is encrypted by first key, transposition cipher is applied under certain order then adds some logical bits, now use second key by One Time Pad Cipher for encryption and again apply transposition cipher, which gives more secure cipher text and vice-versa process applied in decryption part.

Abstract: Khudra is a lightweight block cipher designed for Field Programmable Gate Array (FPGA) based platforms. The cipher has an 18-round generalized type-2 Feistel structure with 64-bit block size. The key schedule takes 80-bit master key and produces 32-bit round keys performing very simple operations. In this work, we analyze the security of Khudra. We first show that the effective round key length is 16-bit. By the help of this observation, we improve the 14-round MITM attack proposed by Youssef et al. by reducing the memory complexity from 2 to 2. Also, we propose a new guess-and-determine type attack on 14 rounds where only 2 known plaintext-ciphertext pairs are required to mount the attack in a time complexity of 2 encryption operations. To the best of our knowledge, this is the best attack in the single key model in terms of time, memory and data complexities where the data complexity is equal to the minimum theoretical data requirement. Moreover, we present two observations on differential probabilities of the round function and the symmetric structure of the cipher. We introduce 2 weak keys for the full cipher by exploiting the symmetric structure of the cipher.

Abstract: Transposition cipher is a class of hystorical encryption algorithms that rearrange positions in plaintext based on some fixed permutation which is its secret key. In this research Differential Evolution was used to attack the transposition cipher, which is a permutation of integer problem. Despite the fact that Differential Evolution mostly used for problem with real numbers; this paper shows that Differential Evolution could be used to correctly decrypt ciphertext that has up to permutation length of 9, but started to have half of incorrect answers in 10 simulations done to permutation length of 10.

Abstract: We show a meet-in-the-middle (MITM) attack with Splice-and-Cut technique (SCT) on the 19-round variant of the block cipher HIGHT. The original HIGHT having 32-round iteration was proposed by Hong et al. in 2006, which applies the 8-branch Type-2 generalized Feistel network (GFN) with 64-bit data block and 128-bit secret key. MITM attack was proposed by Diffie and Hellman in 1977 as a generic method to analyze symmetric-key cryptographic algorithms. SCT was proposed by Aoki and Sasaki to improve MITM attack in 2009. In this paper we show that 19-round HIGHT can be attacked with 28 bytes of memory, 28 + 2 pairs of chosen plain and cipher texts, and 2120.7 times of the encryption operation by using MITM attack with SCT.

Abstract: The HC-128 stream cipher is a successful entrant in the eStream candidate list (software profile) and is the lighter variant of HC-256 stream cipher. Apart from the analysis by the designer of the cipher (Hongjun Wu) to conjecture the security of this cipher, there are only a few other observations on this cipher despite being the focus of researchers during the three phases of eStream evaluation and later efforts in the community. Till date none of the security claims in favor of HC-128 by the designer could be broken. One may expect HC-128 stream cipher to be popular in commercial domain in near future, if not already so. This thesis presents a rigorous study in different aspects of this stream cipher covering combinatorial analysis, distinguishers, design modification proposal, side channel analysis on this cipher and finally implementation strategies. We first show that the knowledge of any one of the two internal state arrays of HC-128 along with the knowledge of 2048 keystream words is sufficient to construct the other state array completely in 242 time complexity. This analysis reveals a structural insight into the cipher’s internal state along with theoretically establishing some novel combinatorial properties of HC-128 keystream generation algorithm. Next, using linear approximation of the addition modulo 2 of three n-bit integers, we identify linear approximations of g1, g2, the feedback functions of HC-128. Here we show that the process of keystream output generation of HC128 can be well approximated by linear functions wherein the “least significant bit" based distinguisher (presented by the designer of the cipher) of HC-128

Abstract: Most of the encryption algorithms used today generates huge cipher messages as well as long encryption keys. These approaches require time and are computationally intensive .While sending data packets through the network a compression technique along with cryptography can be applied to reduce the data packet size for better bandwidth utilization and hence faster transmission of data. In this study we propose a new encryption technique which will encrypt data into reduced size cipher text while keeping the check on size of key. The algorithm was first introduced in an earlier paper. In this study we modified algorithm to preprocess text as well as numeric data.

Abstract: Providing data confidentiality for energyconstrained devices has proven to be a hard problem. Over the years many efficient implementations of well-known block ciphers, as well as a large number of new “lightweight” block ciphers, have been introduced. We propose to distribute block ciphers encryption and decryption operations between a subset of “trusted” nodes. Any block cipher, lightweight or not, can benefit from it. In particular, we analyze the energy consumption of AES128 in Cipher Block Chaining (CBC) mode and measure the energy savings that a distributed computation of AES128-CBC can give. We show that, by leveraging this distributed computation, a node can save up to 73% and up to 81% of the energy normally spent in encryption and decryption, respectively. This has relevant implications in Internet of Things scenarios.

Abstract: Security is required in order to defend information from unauthorized person on the network. Therefore, securely exchanging data over the internet is vital. In this context, cryptography is used that transmute facts from its under stable form into an indecipherable form by using various encryption techniques. Play air cipher is the form of block cipher which has no limit on the number of characters in a message it can do, but it operates on block of characters encrypting and decrypting two characters at a time cipher. In this, the plain text digraphs are converted to cipher text digraphs and vice versa using a pre-shared key. This is achieved by performing several operations column wise row wise and by creating rectangular form. This paper deals with a new solution approach to overcome the shortcomings of the Play air algorithm. In this paper, the presented Play air CBC encryption mechanism makes the cryptanalysis complex. The encrypted text obtained is almost unreadable.

Abstract: Fialka M-125 sometimes called the “Russian Enigma” is an electro-mechanical rotor cipher machine used during the Cold War. The designers of this cipher eliminated the known weaknesses of Enigma. In this article, the authors summarize the main principle of the Fialka algorithm from public sources. Moreover, they introduce a mathematical model of the Fialka cipher, and they analyse the effect of blocking pin settings on the cipher's period.

Abstract: Dr. Preeti Mehta, Ms. Monika Bansal, Ms. Akanksha Upadhyaya 1, 2, 3 Department of MCA, Rukmini Devi Institute of Advanced Studies Abstract— Security and risk management are considered to be data centric. Data, systems and network can be protected for three possible outcomes: confidentiality, integrity and availability. In today’s scenario security of data has become an important issue. Most of the security problems are caused by malicious attackers to cause harm to the sensitive information which is transmitted for specific purpose. The only solution to the problem is cryptographic technique. A theoretical study was made on the DES and AES symmetric encryption algorithms. This research paper majorly focuses on evaluation of performance of two different symmetric encryption techniques on the basis of execution time. Secondary experimental data [1] will be given and hence analyzed for effectiveness of each algorithm.