[01] Kamel Hussein Rahouma, Department of Electrical Engineering, Faculty of Engineering, Minia University, Minia, Egypt.

Software programs can be secured by applying security services. Security service are many and it is important to choose, from them, what suits the software or application under study. In this paper, we discuss a simple software program (the shopper program) and how we can secure it by applying some already existing security algorithms. The program follows up the movement of goods in the store as well as in the shopping place. Visual Basic Dot NET is used to produce the software application. The program uses five files to store its data. The first file is used to save the passwords of the users. The second and third files include the information of goods in the store and the shopping place. The fourth and fifth files save the daily movement in the store and the sales places. For security purposes, the users can use the program without accessing the used files as well as their folders. This is done by changing the files' attributes. The files' attributes are set to: 1) Hiding the file and folders, 2) Read-Only. The files' contents are encrypted to make it hard for the user to recognize these contents. A fast Stream Cipher Encryption/decryption is done using a random key generator. The file's contents are digitally hashed and signed by the user. This guarantees the integrity and authenticity of the files' contents.

Software Security, Stream Ciphers, Cryptography, Hashing, Digital Signature

[01] Wang, C.; J. Davidson; J. Hill and J. Knight (2001): "Protection of software-based survivability mechanisms", The International Conference on Dependable Systems and Networks, Goteborg, Sweden, IEEE Press, pp. 193–205, 2001. [02] Jan M. Memon Asma Khan and Amber Baig Asadullah Shah (2007): "A Study of Software Protection Techniques", in T. Sobh (ed.), Innovations and Advanced Techniques in Computer and Information Sciences and Engineering, 249–253, 2007, Springer [03] WANG, P (2005): "Tamper resistance for software protection". M. S. thesis, School of engineering Information and Communications University, Daejeon, 2005. Available at: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.105.8556&rep=rep1&type=pdf. Accessed in 1^st of July 2016. [04] Koko, Soheila O. and Amin B. Mustafa (2015): "Comparison of Various Encryption Algorithms and Techniques for improving secured data Communication", Journal of Computer Engineering (IOSR-JCE), Volume 17, Issue 1, Ver. III (Jan – Feb. 2015), PP 62-69. [05] Vishwa gupta, Gajendra Singh,. Ravindra Gupta (2012): "Advance cryptography algorithm for improving data security", International Journal of Advanced Research in Computer Science and Software Engineering, Volume 2, Issue 1, January 2012. [06] Stallings, W. (2011): "Cryptography and Network Security Principles and Practice", Prentice Hall, London, Fifth Edition, 2011. [07] Boneh, D. and Shoup, V. (2015): "A Graduate Course in Applied Cryptography", Available in: https://crypto.stanford.edu/~dabo/cryptobook/draft_0_2.pdf, downloaded at: 1/5/2016. [08] Rahouma, Kamel (2000), A chaos-based stream cipher algorithm for high speed networks and real time applications, Presented and published in the Applied telecommunication symposium, as a part of the 2000 advanced simulation technologies conference (ASTC2000), Washington, D. C. USA, April 16-20 2000 [09] TutorialsPoint (2015): "Cryptography just for beginners", TutorialsPoint SimplyEasyLearning, ltd. Available at: http://www.tutorialspoint.com/cryptography/cryptography_tutorial.pdf, Downloaded at 1/6/2016. [10] Smart, N. (2013): "Cryptography: An Introduction", Mcgraw-Hill, 3rd Edition, Ebook (2013). Available at: https://www.cs.umd.edu/~waa/414-F11/IntroToCrypto.pdf, downloaded at 1/6/2015. [11] Ruohonen, K. (2014): "Mathematical Cryptography: A Translation of Lecture Notes in Finnish Language", Translated by Jussi Kangas and Paul Coughlan. Available at: http://math.tut.fi/~ruohonen/MC.pdf, downloaded at 1/6/2016. [12] Rajdeep Bhanot and Rahul Hans (2015): "A Review and Comparative Analysis of Various Encryption Algorithms", International Journal of Security and Its Applications Vol. 9, No. 4 (2015), pp. 289-306. [13] Ajay Kakkar, M. L. Singh, P. K. Bansal (2012): "Comparison of Various Encryption Algorithms and Techniques for Secured Data Communication in Multinode Network", International Journal of Engineering and Technology Volume 2 No. 1, January, 2012. [14] Ajay Kakkar, Dr. M. L. Singh, Dr. P. K. Bansal (2010): “Efficient Key Mechanisms in Multinode Network for Secured Data Transmission”, International Journal of 92 Engineering Science and Technology, Vol. 2, Issue 5, 2010, pp. 787-795. [15] Suyash Verma, Rajnish Choubey, Roopali soni (2012): "An Efficient Developed New Symmetric Key Cryptography Algorithm for Information Security", International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 7, July 2012) 18.