امروزه نهان­نگاری به عنوان هنر یا تکنیکی برای پنهان کردن داده ها در رسانه های مختلف، کاربردهای بسیار متنوعی در مدیریت اطلاعات دارد. نهان­نگاری می­تواند در راستای انتقال یک پیام محرمانه، ارتقاء امنیت، دسته بندی اطلاعات، نگهداری اطلاعات خاص و... مورد استفاده قرارگیرد. تصویر یکی از محبوبترین رسانه­های مورد استفاده در جریان پنهان­سازی داده­ها است و روش­های مختلفی برای نهان­نگاری اطلاعات در تصاویر وجود دارد که متداول­ترین آنها روش جاسازی اطلاعات در بیت­های کم ارزش تصویر می­باشد و برای آن الگوریتم­ها و روش­های متنوعی ابداع شده است. یکی از این روش­ها که مبنای ریاضی دارد، بهره­گیری از محاسبه اختلاف مقادیر دو پیکسل همجوار درجهت شناسایی نقاط مناسب برای جاسازی اطلاعات محرمانه است. در این مقاله دو روش جدید برای نهان نگاری اطلاعات در تصاویر براساس محاسبه میزان تفاوت­های مقادیر پیکسل­های همجوار در بلوک­های 4×4 پیشنهاد و بر روی تصاویر مختلف آزمایش و با استفاده از معیارهای ارزیابی میانگین مربعات خطا، نسبت پیک سیگنال به نویز و شاخص شباهت ساختاری مورد بررسی و تجزیه و تحلیل قرار گرفته است و ارزیابی­ها نشان می­دهد که یکی از روش­های پیشنهادی به­جهت داشتن نتایج بهتر و ظرفیت بیشتر جاسازی اطلاعات مطلوب­ترمی­باشد. One of these methods, which has a mathematical basis, is to use the calculation of the difference between the values of two adjacent pixels in order to identify suitable points for embedding confidential information.In this paper, two new methods for data embedding in images are proposed based on calculating the differences in the values of adjacent pixels in 4 * 4 blocks and tested on different images using the Mean Squares of Errors , Peek signal-to-noise ratio and structural similarity criterias has been studied and analyzed .Evaluations show that the first proposed method is optimal due to better results. تفاصيل المقالة

One the challenging in hardware performance is to designing a high speed calculating unit. The higher of calculations speeds ina computer system will be pointed out in terms of performance. As a result, designing a high speed calculating unit is of utmost importance. In this paper, we start design whit this knowledge that one multiplier made of several adder and one divider made of several sub tractor. Therefore, if the fast adder or fast multiplier designed, performance will be improved. In this design, a circuit is designed in a manner that without a need for transforming numbers or letters from the given bases into binary bases, the multiplication of two numbers for the same base is done in that base. Reduction in the number of conversions in the calculating unit, causes reduction in the consumption power and an increase in the operating speed of the system. In this design, a very small Data Oriented Memory is used to save numerical and character data. تفاصيل المقالة

Providing banking services, especially online banking and electronic payment systems, has always been associated with high concerns about security risks. In this paper, customer authentication for their transactions in electronic banking has been discussed, and a more appropriate way of using biometric fingerprint data, as well as encrypting those data in a different way, has been suggested. Using fingerprint biometrics increases the security of online payment systems.Biometrics is used in a database in the banking system. The fingerprint biometrics is more reliable and easier to use than other biometrics and can be obtained from anyone with an easy access. In this thesis, according to needs analysis, validation is performed not only by the user but also by the bank itself, according to the standards of the banking system.More precisely, a new protocol, known as Stream Cipher, is developed to generate a one-time password from biometric data, to ensure that security and privacy are maintained. In the suggested system, Ciphering and deciphering user information by issuer bank provides security.The results of the research indicate its proper function compared to other authentication methods. The protocol security analysis also demonstrates the benefits of enhancing security by employing the accelerated encryption methods in the proposed method. The results of the research show The Errors rate (EER, FRR and SFAR) is very low and can be ignored. This method is highly resistant to all kinds of electronic banking attacks, such as phishing and password theft. تفاصيل المقالة