Code Analysis for Software and System Security Using Open Source Tools

ABSTRACT

Software security helps in identifying and managing risks. One of the effective ways to identify software vulnerabilities is to analyze its code. Code analysis (Chess & West, 2007 Chess, B. and West, J. 2007. Secure programming with static analysis, Boston, MA: Addison-Wesley.  [Google Scholar]) helps in catching common coding mistakes such as buffer overflow, unused variables, memory leaks, and various race conditions, which in turn optimizes computer programs, both in storage and computation aspects. Software developers use either open source tools or commercial tools for verification and validation of software. Without proper validation of a software/system using some standard guidelines, potential attackers can find ways to exploit vulnerabilities and bugs and then can gain control over a system, if they are successful. In this paper, we discuss some of the open source static code analysis and dynamic analysis tools, their merits, and limitations with respect to some target codes that contain possible threats. We consider C/C++ and Java programming languages for our experiments. For static code analyzers, we consider Flawfinder, Splint, and Cppcheck; PMD, Findbugs, and Valgrind for dynamic code analysis, and its plug-in, Memcheck, to perform dynamic analysis on executables. We provide our observations in a comparison table, highlighting these tools strengths and weaknesses.     

The XTS-AES Disk Encryption Algorithm and the Security of Ciphertext Stealing

Abstract

This paper describes the importance of the XTS-AES encryption mode of operation and concludes with a new proof for the security of ciphertext stealing as used by XTS-AES. The XTS-AES mode is designed for encrypting data stored on hard disks where there is not additional space for an integrity field. Given this lack of space for an integrity field, XTS-AES builds on the security of AES by protecting the storage device from many dictionary and copy/paste attacks. The operation of the XTS mode of AES is defined in the IEEE 1619-2007 standard [3 IEEE Std 1619–2007 . April 18, 2008 . The XTS-AES Tweakable Block Cipher. Institute of Electrical and Electronics Engineers, Inc.  [Google Scholar]], and has been adopted by the U.S. National Institute of Standards and Technology (NIST) as an approved mode of operation under FIPS 140-2 [2 Dworkin , M. December 2009 . NIST SP 800-38E, “Recommendation for Block Cipher Modes of Operation: The XTS-AES Mode for Confidentiality on Storage Devices”.  [Google Scholar]]. XTS-AES builds on the XEX (Xor-Encrypt-Xor) mode originally proposed by Rogaway [8 Rogaway , P. 2004 . Efficient Instantiations of Tweakable Block ciphers and Refinements to Modes OCB and PMAC. Advances in Cryptology–Asiacrypt 2004, Lecture Notes in Computer Science, vol. 3329, Springer-Verlag, pp. 16–31. Available at http://www.cs.ucdavis.edu/rogaway/papers/offsets.pdf (Accessed 6 January 2012) . [Google Scholar]].     

Optimal control of the production–inventory system with deteriorating items and tradable emission permits

Using the well-known Arrow and Karlin (1958) Arrow, K.J., and Karlin, S. (1958), ‘Production over Time with Increasing Marginal Costs’, in Studies in the Mathematical Theory of Inventory and Production, eds. K.J. Arrow and S. Karlin, Stanford: Stanford University Press, pp. 61–69. [Google Scholar] dynamic production–inventory model and the model with tradable emission permits which was presented by Dobos (2005 Dobos, I. (2005), ‘The Effects of Emission Trading on Production and Inventories in the Arrow–Karlin Model’, International Journal of Production Economics, 93–94, 301–308.[Crossref], [Web of Science ®] , [Google Scholar], 2007) Dobos I. (2007), ‘Tradable Emission Permits and Production-inventory Strategies of the Firm’, International Journal of Production Economics, 108, 329–333.[Crossref], [Web of Science ®] , [Google Scholar], we develop a model of the production–inventory system with deteriorating items and tradable emission permits. The objective of this paper is to apply the optimal control theory to solve the production–inventory problem with deteriorating items and tradable emission permits, and derive the optimal inventory level and the optimal production rate that minimise the total cost. The results are discussed with a numerical example and a sensitivity analysis of the optimal solution with respect to the parameters of the production–inventory system is carried out.     

MGR Hash Functions

Abstract

GOST-R 34.11-94 is a Russian standard cryptographic hash function that was introduced in 1994 by the Russian Federal Agency for the purposes of information processing, information security, and digital signature. Mendel et al. (2008 Mendel, F., N. Pramstaller, C. Rechberger, M. Kontak, and J. Szmidt. 2008. Cryptanalysis of the GOST hash function, Advances in Cryptology – CRYPTO 2008, vol. 5157, 162–178. [Google Scholar]) and Courtois and Mourouzis (2011 Courtois, N., and T. Mourouzis. 2011. Black-box collision attacks on the compression function of the GOST hash function. SECRYPT. Proceedings of the International Conference on Security and Cryptography, 325–332, IEEE. [Google Scholar]) found attacks on the compression function of the GOST-R structure that were basically weaknesses of the GOST-R block cipher (GOST 28147–89, 1989 GOST 28147-89. 1989. Systems of the information treatment, cryptographic security, algorithms of the cryptographic transformation (in Russian). [Google Scholar]). Hence in 2012, it was updated to GOST-R 34.11-2012, which replaced the older one for all its applications from January 2013. GOST-R 34.11-2012 is based on a modified Merkle-Damgård construction. Here we present a modified version of GOST-R 34.11-2012 (Modified GOST-R (MGR) hash). The design of the MGR hash is based on wide-pipe construction, which is also a modified Merkle-Damgård construction. MGR is much more secure as well as three times faster than GOST-R 34.11-2012. Advanced Encryption Standard (AES)-like block ciphers have been used in designing the compression function of MGR because AES is one of the most efficient and secure block ciphers and has been evaluated for more than 14?years. A detailed statistical analysis with a few other attacks on MGR is incorporated into this paper.     

MOBILE AGENT SECURITY AGAINST MALICIOUS PLATFORMS

This article presents a review of security mechanisms that have been developed for mobile agent security against malicious platforms. It has been almost 10 years since a prominent review of security in agent systems was presented by Jansen (2000 Jansen , W. 2000 . Countermeasures for mobile agent security . Computer Communications 23 ( 17 ): 1667 – 1676 . [Google Scholar]). We present new developments that have been suggested over the years, evaluate limitations of these schemes, and highlight possible areas of improvement. This article further presents possible threats to the mobile agent paradigm and distinguishes between detection and prevention security mechanisms.     

An Embedding Based IR Model for Disaster Situations

Twitter (http://twitter.com) is one of the most popular social networking platforms. Twitter users can easily broadcast disaster-specific information, which, if effectively mined, can assist in relief operations. However, the brevity and informal nature of tweets pose a challenge to Information Retrieval (IR) researchers. In this paper, we successfully use word embedding techniques to improve ranking for ad-hoc queries on microblog data. Our experiments with the ‘Social Media for Emergency Relief and Preparedness’ (SMERP) dataset provided at an ECIR 2017 workshop show that these techniques outperform conventional term-matching based IR models. In addition, we show that, for the SMERP task, our word embedding based method is more effective if the embeddings are generated from the disaster specific SMERP data, than when they are trained on the large social media collection provided for the TREC (http://trec.nist.gov/) 2011 Microblog track dataset.     

A Unified User Management System

ABSTRACT

As open source software has gained in popularity throughout the last decades, free operating systems (OSs) such as Linux (Torvalds) and BSD derivatives (i.e., FreeBSD, 2012; NetBSD, 2012 NetBSD Foundation. (2012). The NetBSD project. Available from http://netbsd.org (http://netbsd.org)  [Google Scholar]; OpenBSD, 2012 OpenBSD. (2012). OpenBSD. OpenBSD. Available from http://netbsd.org (http://netbsd.org)  [Google Scholar]) have become more common, not only on datacenters but also on desktop and laptop computers. It is not rare to find computer labs or company offices composed of personal computers that boot more than one operating system. By being able to choose among available OSs, a company's or organization's information technology manager has the freedom to select the right OS for the company's needs, and the decision can be based on technical or financial criteria. This freedom of choice, however, comes with a cost. The administrative complexity of heterogeneous networks is much higher compared to single OS networks, and if the network is large enough so that protocols such as LDAP (Zeilenga, 2006 Zeilenga, K. 2006. Lightweight directory access protocol (LDAP): Technical specification road map et. alTech. rep., RFC 4510, June [Google Scholar]) or Kerberos (Kohl & Neuman, 1993 Kohl, J. and Neuman, C. 1993. The Kerberos network authentication service (v5) Tech. rep., RFC 1510, September[Crossref] , [Google Scholar]) need to be adopted, then the administration burden may become unbearable. Even though some tools exist that make user management of heterogeneous networks more feasible (Tournier, 2006 Tournier, J. (2006). smbldap-tools – summary [Gna!]. In Welcome to Gna! http://gna.org/projects/smbldap-tools (http://gna.org/projects/smbldap-tools)  [Google Scholar]; Chu & Symas Corp., 2005 Chu, H. and Symas Corp. (2005) http://www.openldap.org/devel/cvsweb.cgi/~checkout~/contrib/slapd-modules/smbk5pwd/README (http://www.openldap.org/devel/cvsweb.cgi/~checkout~/contrib/slapd-modules/smbk5pwd/README)  [Google Scholar]), it is not uncommon to use more than one back end for storing user credentials due to OS incompatibilities. In such configurations, the hardest problem to address is credential and account expiration synchronization among the different back ends. This paper demonstrates a platform that tries to mitigate the problem of synchronization by adding an additional, modular, easy to expand layer which is responsible for synchronizing any number of underlying back ends in a secure fashion.     

The motion planning problem and exponential stabilisation of a heavy chain. Part I†

A model of a heavy chain system with a punctual load (tip mass) in the form of a system of partial differential equations is interpreted as an abstract semigroup system on a Hilbert state space. Our aim is to solve the output motion planning problem of the same nature as in the case of an unloaded heavy chain (Grabowski, P. (2003 Grabowski, P. 2003. Abstract Semigroup Model of Heavy Chain System with Application to a Motion Planning Problem. Proceedings of 9th IEEE International Conference: Methods and Models in Automation and Robotics. 25–28 August2003, Mi?dzyzdroje, Poland. pp.77–86. (IS1-2-3.PDF) [Google Scholar]), ‘Abstract Semigroup Model of Heavy Chain System with Application to a Motion Planning Problem’, in Proceedings of 9th IEEE International Conference: Methods and Models in Automation and Robotics, 25–28 August, Mi?dzyzdroje, Poland, pp. 77–86 (IS1-2-3.PDF)). In order to solve this problem we first analyse its well-posedness and some basic properties. Next, we solve the output motion planning problem using a substitute of the inverse of the input–output operator represented in terms of the Laplace transforms. A problem of exponential stabilisation is also formulated and solved using a stabiliser of the colocated type. The exponential stabilisation is proved using the method of Lyapunov functionals combined with some frequency-domain tools. The method of Lyapunov functionals can be replaced by the spectral or exact controllability approach as shown in the second part (Grabowski, P. (2008 Grabowski, P. 2008. ‘The Motion Planning Problem and Exponential Stabilisation of a Heavy Chain. Part II’. Opuscula Mathematica, 28: 481–505. (2008) (Special issue dedicated to the memory of Professor Andrzej Lasota) [Google Scholar]), ‘The Motion Planning Problem and Exponential Stabilisation of a Heavy Chain. Part II’, Opuscula Mathematica, 28 (2008 Grabowski, P. 2008. ‘The Motion Planning Problem and Exponential Stabilisation of a Heavy Chain. Part II’. Opuscula Mathematica, 28: 481–505. (2008) (Special issue dedicated to the memory of Professor Andrzej Lasota) [Google Scholar]) (Special issue dedicated to the memory of Professor Andrzej Lasota), 481–505) of the present article. A laboratory setup which allows verification of the results in practice is described in detail. Its dynamical model is used as an example to illustrate the theoretical results.     

Mapping the image

The Brainstorm feature introduced in Adobe After Effects CS3 (2007) allows users to automate parts of the process of generating design variations for the purposes of comparison and selection. The paper begins with a brief discussion of current discursive formations around software and software-based practice among digital design practitioners and educators. Next, the paper draws upon critical concepts drawn from multimodal discourse analysis, media theory and sociology to analyse Brainstorm in terms of the interplay of software structure and design agency. The key concepts used are modality, articulation and interpretation (Kress and van Leeuwen 1996 Kress, G. and van Leeuwen, T. 1996. Reading images: the grammar of visual design, London: Routledge.  [Google Scholar], 2001), the database as cultural form and the logic of selection (Manovich 2001 Manovich, L. 2001. The language of new media, Cambridge, MA: MIT Press.  [Google Scholar]), habitus and practical logic (Bourdieu 1977 Bourdieu, P. 1977. Outline of a theory of practice, New York: Cambridge University Press. [Crossref] , [Google Scholar]) and the radius of creativity (Toynbee 2000 Toynbee, J. 2000. Making popular music: musicians, creativity and institutions, London: Arnold.  [Google Scholar]). Throughout, the paper addresses specific structural features of the software, thus developing an overview of the affordances and constraints of Brainstorm as a creative tool.     

Information Assurance Metric for Assessing NIST's Monitoring Step in the Risk Management Framework

ABSTRACT

This paper proposes an information assurance (IA) metric that can be used to measure the security posture of an enterprise system in the “monitoring” step (Step 6) of the risk management framework (RMF), as required in the new certification and accreditation (C&A) process described in NIST SP 800-37, Rev. 1, Guide for Applying the Risk Management Framework to Federal Information Systems: A Security Life Cycle Approach. This metric was developed by adopting the Object Measurement (OM® ¹ 1. OM® - Registered trademark owned by Donaldson and Siegel, SAIC, (1997) Donaldson, S. E. and Siegel, S. G. 1997. Cultivating successful software development, 1st, Upper Saddle River, NJ: Prentice Hall.  [Google Scholar]. ) approach, created to evaluate system development life cycle (SDLC) processes, for use as an IA metric. This metric supports organizational management's decision-making processes by enabling an organization to determine how well a system is complying with its monitoring plan. The values obtained through use of this metric can be abstracted to roll up values from multiple systems, creating an aggregate measure usable by organizational management to assess the security posture of all, or a subset, of their accredited systems undergoing monitoring.     

Mean-square stability and error analysis of implicit time-stepping schemes for linear parabolic SPDEs with multiplicative Wiener noise in the first derivative

In this article, we extend a Milstein finite difference scheme introduced in 8 Giles, M. B. and Reisinger, C. 2012. Stochastic finite differences and multilevel Monte Carlo for a class of SPDEs in finance. SIAM Financ. Math., 3(1): 572–592. (doi:10.1137/110841916)[Crossref] , [Google Scholar] for a certain linear stochastic partial differential equation (SPDE) to semi-implicit and fully implicit time-stepping as introduced by Szpruch 32 Szpruch, L. 2010. Numerical approximations of nonlinear stochastic systems PhD Thesis, University of Strathclyde [Google Scholar] for stochastic differential equations (SDEs). We combine standard finite difference Fourier analysis for partial differential equations with the linear stability analysis in 3 Buckwar, E. and Sickenberger, T. 2011. A comparative linear mean-square stability analysis of Maruyama- and Milstein-type methods. Math. Comput. Simulation, 81: 1110–1127. (doi:10.1016/j.matcom.2010.09.015)[Crossref], [Web of Science ®] , [Google Scholar] for SDEs to analyse the stability and accuracy. The results show that Crank–Nicolson time-stepping for the principal part of the drift with a partially implicit but negatively weighted double Itô integral gives unconditional stability over all parameter values and converges with the expected order in the mean-square sense. This opens up the possibility of local mesh refinement in the spatial domain, and we show experimentally that this can be beneficial in the presence of reduced regularity at boundaries.     

A Structuration Agency Approach to Security Policy Enforcement in Mobile Ad Hoc Networks

ABSTRACT

A mobile ad hoc network (MANET) is a self-organizing, self-configuring confederation of wireless systems. MANET devices join and leave the network asynchronously at will, and there are no predefined client or server roles – roles change based on the nature of a given communication. The dynamic topologies, mobile communications structure, decentralized control, and anonymity creates many challenges to the security of systems and network infrastructure in a MANET environment. Consequently, this extreme form of dynamic and distributed model requires a reevaluation of conventional approaches to security enforcements. Recent developments in agent frameworks have contributed to some potential solutions for security policy enforcements for MANETs. Building on these developments, and extending principles from structuration theory (Giddens, 1984 Giddens, A. 1984. The constitution of society: Outline of the theory of structuration, Cambridge, , UK: Polity Press.  [Google Scholar]), we formulated a socio-biologically inspired approach to MANET security we refer to as structuration agency theory.     

A MULTI-AGENT SYSTEM FOR THE MANAGEMENT OF ABNORMAL SITUATIONS IN AN ARTIFICIALLY GAS-LIFTED WELL

Concerning industrial automation, the management of abnormal situations becomes more important everyday. The ability to detect, isolate, and handle abnormal situations in industrial installations, could save huge amounts of money which is normally invested in reparations and/or wasted because of unjustified stoppage of processing plants. In this work, a system for the management of abnormal situations in an artificially gas-lifted well based on agents Abnormal Situations Management System (ASMS) is developed, which is part of the architecture of the industrial automation based on multi-agents systems (SADIA) proposed in Bravo, Aguilar, and Rivas (2004 Bravo , C. , J. Aguilar , and F. Rivas. 2004 . Diseño de una Arquitectura de Automatización Industrial Basada en Sistemas Multiagentes . Revista Ciencia e Ingeniería, Facultad de Ingeniería 25 ( 2 ): 77 – 88 . [Google Scholar]). This agent is based on the intelligent distributed control system based on agents (IDCSBA) reference model proposed in Aguilar, Cerrada, Mousalli, Rivas, and Hidrobo (2005 Aguilar , J. , M. Cerrada , G. Mousalli , F. Rivas , and F. Hidrobo. 2005 . A multiagent model for intelligent distributed control systems . Lecture Notes in Artificial Intelligence 3681 : 191 – 197 . [Google Scholar]). The MASINA methodology (Aguilar, Hidrobo, and Cerrada 2007 Aguilar , J. , F. Hidrobo , and M. Cerrada. 2007 . A methodology to specify multiagent systems . Lecture Notes in Artificial Intelligence 4496 : 92 – 101 . [Google Scholar]) is used in matters of analysis, design, and implementation.     

Age Diversity: An Empirical Study in the Board of Directors

This study aims to explore how board age diversity affects corporate performance. This study develops three hypotheses built on the perspective of the upper echelons and Harrison and Klein's (2007 Harrison, D. and K. Klein. “What's the Difference? Diversity Constructs as Separation, Variety, or Disparity in Organizations.” Academy of Management Review 32, no. 4 (2007): 1199–1228.[Crossref], [Web of Science ®] , [Google Scholar]) diversity typology. Focusing on age diversity and using a board of directors as a unit of analysis, this study empirically tests the effects of each type of age diversity on corporate performance in a sample of European listed firms for the year 2009. This study advances the understanding of board behavior and its relationships with corporate results, and presents a new approach to study age diversity from an integrated point of view.     

A Motivationally Oriented Approach to Understanding Game Appropriation

Game appropriation is currently not well conceptualized. What literature does exists (Griffiths & Light, 2008 Griffiths, M. and Light, B. 2008. Social networking and digital gaming media convergence: Classification and its consequences for appropriation. Information Systems Frontiers, 10: 447–459. [Crossref], [Web of Science ®] , [Google Scholar]; Lowood, 2005 Lowood, H. 2005. Real-time performance: Machinima and game studies. The International Media and Art Association Journal, 1(3): 10–16.  [Google Scholar]; Postigo, 2008 Postigo, H. 2008. Video game appropriation through modifications. Attitudes concerning intellectual property among modders and fans. Convergence, 14: 59–74.  [Google Scholar]; Stalker, 2005 Stalker, P. J. (2005). Gaming in art. Unpublished master's thesis, University of the Witwatersrand, Johannesburg, South Africa. http://www.selectparks.net/dl/PippaStalker_GamingInArt.pdf (http://www.selectparks.net/dl/PippaStalker_GamingInArt.pdf)  [Google Scholar]) uses the term primarily to denote gamers' practices beyond the designers' original intentions, for instance, game content modifications. This article frames game appropriation in a different manner; unlike existing appropriation models, game appropriation is conceptualized as a motivational process underpinned by three primary factors: game design characteristics, social interaction, and the psychological characteristics of the gamer. The main contribution of this article is the development of the first model of game appropriation, the game appropriation model (GAM). GAM explains the process of digital games' incorporation into gamers' daily practices as well as the nature of their gameplay. Game appropriation recognizes the online–offline continuity; it contributes to understating gameplay as a long-term, dynamic activity, directly interrelated with a gamers' everyday life rather than a set of defined moments of participation.     

A comparative assessment of IRS-P4 (MSMR)-derived sea surface temperature and sea surface wind speed over the north Indian Ocean

Indian Remote Sensing Satellite (IRS-P4) multi-frequency scanning microwave radiometer (MSMR) provides geophysical parameters like sea surface temperature (SST), sea surface wind speed (SSWS), integrated water vapour (IWV) and cloud liquid water (CLW). The retrieval procedure of these parameters given by Gohil et al. (2000 Gohil, B.S., Mathur, A.K. and Varma, A.K. Geophysical parameter retrieval over global oceans from IRS-P4 (MSMR). Preprints, Fifth Pacific Ocean Remote Sensing Conference. December5–82000, Goa. pp.207–211. Goa, , India: National Institute of Oceanography.  [Google Scholar], Geophysical parameter retrieval over global oceans from IRS-P4 (MSMR). In Preprints, Fifth Pacific Ocean Remote Sensing Conference, 5–8 December 2000, Goa, India (Goa: National Institute of Oceanography), pp. 207–211) was summarized by Sharma et al. (2002 Sharma, R., Babu, K.N., Mathur, A.K. and Ali, M.M. 2002. Identification of large scale atmospheric and oceanic features from IRS-P4 multifrequency scanning microwave radiometer: preliminary results. Journal of Atmospheric and Oceanic Technology, 19: 1127–1134. [Crossref], [Web of Science ®] , [Google Scholar], Identification of large scale atmospheric and oceanic features from IRS-P4 multifrequency scanning microwave radiometer: preliminary results. Journal of Atmospheric and Oceanic Technology, 19, pp. 1127–1134) and Jena (2007 Jena, B. 2007. Studies on the retrieval, validation and applications of geophysical parameters from IRS-P4 (MSMR) data, Orissa: PhD thesis, Berhampur University.  [Google Scholar], Studies on the retrieval, validation and applications of geophysical parameters from IRS-P4 (MSMR) data. PhD thesis, Berhampur University, Orissa). Demonstration of self-consistency of these parameters has primary scientific importance. This article deals with the validation of MSMR geophysical parameters such as SST and SSWS with in situ observations (buoy data) over the north Indian Ocean during 2000. Result shows that the MSMR-derived SST and SSWS can be utilized for several applications because of their reasonable accuracy and coverage even under cloudy condition.     

A Novel High Quality High Capacity Image Hiding Scheme Based on Image Compression and an Optical Pixel Adjustment Process

ABSTRACT

Image hiding methods embed a secret image into a host image. The resultant stego-image does not attract the interceptors that would not detect the differences between the host image and the stego-image. To exploit the great developments in the area of image compression and to improve the quality of stego-image, this paper proposes a new method to embed the secret image into the host image. Basically, the secret image is compressed and then embedded into host image. The embedding method is based on the Optimal Pixel Adjustment Process (OPAP) and genetic algorithm. In the paper we addressed the important issues to build such systems. The experimental results showed that the proposed method can improve the quality from 60% to 80% when compared with the simple Least Significant Bit (LSB) replacement methods. Adding to that, the mean square error of the stego-image is much lower compared with other methods (Chan & Cheng, 2004 Chan, C.K. and Cheng, L.M. 2004. Hiding data in images by simple LSB substitution. Pattern Recognition, 37(3): 469–474. [Crossref], [Web of Science ®] , [Google Scholar]; Chang, Hsiao, & Chan, 2003 Chang, C.C., Hsiao, J.Y. and Chan, C.S. 2003. Finding optimal least-significant-bit substitution in image hiding by dynamic programming strategy. Pattern Recognition, 36(7): 1583–1595. [Crossref], [Web of Science ®] , [Google Scholar]; Thien & Lin, 2003 Thien, C.C. and Lin, J.C. 2003. A simple and high-hiding capacity method for hiding digit-by-digit data in images based on modulus function. Pattern Recognition, 36(12): 2875–2881. [Crossref], [Web of Science ®] , [Google Scholar]; Tseng, Chan, Ho, & Chu, 208; Wang, Lin, & Lin, 2001 Wang, R.Z., Lin, C.F. and Lin, J.C. 2001. Image hiding by optimal LSB substitution and genetic algorithm. Pattern Recognition, 34(3): 671–683. [Crossref], [Web of Science ®] , [Google Scholar]). Also, the proposed technique improves capacity. In other words, we can embed a secret image with size 450?×?450 inside a hosting image with size 512?×?512.     

A parallel time-memory tradeoff attack on the Hill cipher

Leap et al. (2016 Leap, T., T. McDevitt, K. Novak, and N. Siermine. 2016. Further improvements to the Bauer-Millward attack on the Hill cipher. Cryptologia 40:1–16.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) reduced the time complexity of the Bauer-Millward (2007 Bauer, C., and K. Millward. 2007. Cracking matrix encryption row by row. Cryptologia 31(1):76–83.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) ciphertext-only attack on the Hill cipher from 𝒪(Lⁿ) to 𝒪(L^n?1), where L is the length of the alphabet, and n is the block size. This article presents an attack that reduces the complexity to 𝒪(L^n?1?s), 0?≤?s?≤?n???1. The practical limitation on the size of s is the memory available on the computer being used for the attack. Specifically, the computer must be able to hold L^s integer arrays of length N, where N is the number of blocks of ciphertext. The key idea is not to iterate over potential rows of the decryption matrix, but to iterate over randomly chosen characters in the plaintext. This attack also admits a straightforward parallel implementation on multiple processors to further decrease the run time of the attack.