307 research outputs found
RC4 Encryption-A Literature Survey
AbstractA chronological survey demonstrating the cryptanalysis of RC4 stream cipher is presented in this paper. We have summarized the various weaknesses of RC4 algorithm followed by the recently proposed enhancements available in the literature. It is established that innovative research efforts are required to develop secure RC4 algorithm, which can remove the weaknesses of RC4, such as biased bytes, key collisions, and key recovery attacks on WPA. These flaws in RC4 are still offering an open challenge for developers. Hence our chronological survey corroborates the fact that even though researchers are working on RC4 stream cipher since last two decades, it still offers a plethora of research issues. The attraction of community towards RC4 is still alive
Year 2010 Issues on Cryptographic Algorithms
In the financial sector, cryptographic algorithms are used as fundamental techniques for assuring confidentiality and integrity of data used in financial transactions and for authenticating entities involved in the transactions. Currently, the most widely used algorithms appear to be two-key triple DES and RC4 for symmetric ciphers, RSA with a 1024-bit key for an asymmetric cipher and a digital signature, and SHA-1 for a hash function according to international standards and guidelines related to the financial transactions. However, according to academic papers and reports regarding the security evaluation for such algorithms, it is difficult to ensure enough security by using the algorithms for a long time period, such as 10 or 15 years, due to advances in cryptanalysis techniques, improvement of computing power, and so on. To enhance the transition to more secure ones, National Institute of Standards and Technology (NIST) of the United States describes in various guidelines that NIST will no longer approve two-key triple DES, RSA with a 1024-bit key, and SHA-1 as the algorithms suitable for IT systems of the U.S. Federal Government after 2010. It is an important issue how to advance the transition of the algorithms in the financial sector. This paper refers to issues regarding the transition as Year 2010 issues in cryptographic algorithms. To successfully complete the transition by 2010, the deadline set by NIST, it is necessary for financial institutions to begin discussing the issues at the earliest possible date. This paper summarizes security evaluation results of the current algorithms, and describes Year 2010 issues, their impact on the financial industry, and the transition plan announced by NIST. This paper also shows several points to be discussed when dealing with Year 2010 issues.Cryptographic algorithm; Symmetric cipher; Asymmetric cipher; Security; Year 2010 issues; Hash function
MV3: A new word based stream cipher using rapid mixing and revolving buffers
MV3 is a new word based stream cipher for encrypting long streams of data. A
direct adaptation of a byte based cipher such as RC4 into a 32- or 64-bit word
version will obviously need vast amounts of memory. This scaling issue
necessitates a look for new components and principles, as well as mathematical
analysis to justify their use. Our approach, like RC4's, is based on rapidly
mixing random walks on directed graphs (that is, walks which reach a random
state quickly, from any starting point). We begin with some well understood
walks, and then introduce nonlinearity in their steps in order to improve
security and show long term statistical correlations are negligible. To
minimize the short term correlations, as well as to deter attacks using
equations involving successive outputs, we provide a method for sequencing the
outputs derived from the walk using three revolving buffers. The cipher is fast
-- it runs at a speed of less than 5 cycles per byte on a Pentium IV processor.
A word based cipher needs to output more bits per step, which exposes more
correlations for attacks. Moreover we seek simplicity of construction and
transparent analysis. To meet these requirements, we use a larger state and
claim security corresponding to only a fraction of it. Our design is for an
adequately secure word-based cipher; our very preliminary estimate puts the
security close to exhaustive search for keys of size < 256 bits.Comment: 27 pages, shortened version will appear in "Topics in Cryptology -
CT-RSA 2007
ECSC-128: New Stream Cipher Based On Elliptic Curve Discrete Logarithm Problem.
Ecsc-128 is a new stream cipher based on the intractability of the Elliptic curve discrete logarithm problem. The design of ECSC-l2g is divided into three important stages: Initialization Stage, Keystream Generation stage,
and the Encryption Stage. The design goal of ECSC-128 is to come up with a secure stream cipher for data encryption. Ecsc-l2g was designed based on some hard mathematical problems instead of using simple logical operations. In
terms of performance and security, Ecsc-l2g was slower, but it provided high level of security against all possible cryptanalysis attacks
SAFE-NET: Secure and Fast Encryption using Network of Pseudo-Random Number Generators
We propose a general framework to design a general class of random number generators suit- able for both computer simulation and computer security applications. It can include newly pro- posed generators SAFE (Secure And Fast Encryption) and ChaCha, a variant of Salsa, one of the four finalists of the eSTREAM ciphers. Two requirements for ciphers to be considered se- cure is that they must be unpredictable with a nice distributional property. Proposed SAFE-NET is a network of n nodes with external pseudo-random number generators as inputs nodes, several inner layers of nodes with a sequence of random variates through ARX (Addition, Rotation, XOR) transformations to diffuse the components of the initial state vector. After several rounds of transformations (with complex inner connections) are done, the output layer with n nodes are outputted via additional transformations. By utilizing random number generators with desirable empirical properties, SAFE-NET injects randomness into the keystream generation process and constantly updates the cipher’s state with external pseudo-random numbers during each iteration. Through the integration of shuffle tables and advanced output functions, extra layers of security are provided, making it harder for attackers to exploit weaknesses in the cipher. Empirical results demonstrate that SAFE-NET requires fewer operations than ChaCha while still producing a sequence of uniformly distributed random numbers
Near Collisions in the RC4 Stream Cipher
In this paper we explore the intriguing factors involved in the non one-one nature of the RC4, and explore new techniques and present interesting findings regarding the same. The first part of this paper studies near colliding keys of the RC4, and discusses how these keys are localized into clusters in the key-space. The second part of this paper proposes a new collision search algorithm specifically for 16-byte keys. It is generally the practice to choose the byte that differs between two keys to be near the end of the key. However, this is not necessary for 16-byte keys, and the second part of this paper discusses how this may be used to grant us an additional degree of control
Energy Efficient Security Framework for Wireless Local Area Networks
Wireless networks are susceptible to network attacks due to their inherentvulnerabilities. The radio signal used in wireless transmission canarbitrarily propagate through walls and windows; thus a wireless networkperimeter is not exactly known. This leads them to be more vulnerable toattacks such as eavesdropping, message interception and modifications comparedto wired-line networks. Security services have been used as countermeasures toprevent such attacks, but they are used at the expense of resources that arescarce especially, where wireless devices have a very limited power budget.Hence, there is a need to provide security services that are energy efficient.In this dissertation, we propose an energy efficient security framework. Theframework aims at providing security services that take into account energyconsumption. We suggest three approaches to reduce the energy consumption ofsecurity protocols: replacement of standard security protocol primitives thatconsume high energy while maintaining the same security level, modification ofstandard security protocols appropriately, and a totally new design ofsecurity protocol where energy efficiency is the main focus. From ourobservation and study, we hypothesize that a higher level of energy savings isachievable if security services are provided in an adjustable manner. Wepropose an example tunable security or TuneSec system, which allows areasonably fine-grained security tuning to provide security services at thewireless link level in an adjustable manner.We apply the framework to several standard security protocols in wirelesslocal area networks and also evaluate their energy consumption performance.The first and second methods show improvements of up to 70% and 57% inenergy consumption compared to plain standard security protocols,respectively. The standard protocols can only offer fixed-level securityservices, and the methods applied do not change the security level. The thirdmethod shows further improvement compared to fixed-level security by reducing(about 6% to 40%) the energy consumed. This amount of energy saving can bevaried depending on the configuration and security requirements
Design implementation and analysis of a dynamic cryptography algorithm with applications
Cryptographers need to provide the world with a new encryption standard. DES, the major encryption algorithm for the past fifteen years, is nearing the end of its useful life. Its 56-bit key size is vulnerable to a brute-force attack on powerful microprocessors and recent advances in linear cryptanalysis and differential cryptanalysis indicate that DES is vulnerable to other attacks as well. A more recent attack called XSL, proposes a new attack against AES and Serpent. The attack depends much more critically on the complexity of the nonlinear components than on the number of rounds. Ciphers with small S-boxes and simple structures are particularly vulnerable. Serpent has small S-boxes and a simple structure. AES has larger S-boxes, but a very simple algebraic description. If the attack is proven to be correct, cryptographers predict it to break AES with a 2; 80 complexity, over the coming years; Many of the other unbroken algorithms---Khufu, REDOC II, and IDEA---are protected by patents. RC2 is broken. The U.S. government has declassified the Skipjack algorithm in the Clipper and Capstone chips
Fast and Accurate Machine Learning-based Malware Detection via RC4 Ciphertext Analysis
Malware is dramatically increasing its viability while hiding its malicious intent and/or behavior by employing ciphers. So far, many efforts have been made to detect malware and prevent it from damaging users by monitoring network packets. However, conventional detection schemes analyzing network packets directly are hardly applicable to detect the advanced malware that encrypts the communication. Cryptoanalysis of each packet flowing over a network might be one feasible solution for the problem. However, the approach is computationally expensive and lacks accuracy, which is consequently not a practical solution. To tackle these problems, in this paper, we propose novel schemes that can accurately detect malware packets encrypted by RC4 without decryption in a timely manner. First, we discovered that a fixed encryption key generates unique statistical patterns on RC4 ciphertexts. Then, we detect malware packets of RC4 ciphertexts efficiently and accurately by utilizing the discovered statistical patterns of RC4 ciphertext given encryption key. Our proposed schemes directly analyze network packets without decrypting ciphertexts. Moreover, our analysis can be effectively executed with only a very small subset of the network packet. To the best of our knowledge, the unique signature has never been discussed in any previous research. Our intensive experimental results with both simulation data and actual malware show that our proposed schemes are extremely fast (23.06±1.52 milliseconds) and highly accurate (100%) on detecting a DarkComet malware with only a network packet of 36 bytes
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