Online Payment System Using Steganography and Visual Cryptography

Transcription

1 Volume-5, Issue-6, December-2015 International Journal of Engineering and Management Research Page Number: Online Payment System Using Steganography and Visual Cryptography T. Venu Gopal Associate Professor, ECE, Vidya Jyothi Institute of Technology, Aziz Nagar, C.B. Post, INDIA ABSTRACT The main aim of this paper is an online payment system using steganography and visual cryptography. Steganography is the art of hiding of a message another so that hidden message is indistinguishable. Visual Cryptography is a cryptographic technique based on visual secret sharing used for image encryption. Keywords--- Steganography, Cryptography, visual secret sharing, image encryption, image decryption, matlab. I. INTRODUCTION 1.1 Objective of paper: The main of this paper is an online payment system using steganography and visual cryptography.steganography is the art of hiding of a message another so that hidden message is indistinguishable.visual Cryptography is a cryptographic technique based on visual secret sharing used for image encryption. 1.2 Block Diagram 391 Copyright Vandana Publications. All Rights Reserved.

2 1.2 (b) Proposed payment methods: 1.3 Description: Transaction in Online Shopping: In traditional online shopping as shown in Fig. 1.2(a) consumer selects items from online shopping portal and then is directed to the payment page. Online merchant may have its own payment system or can take advantage of third party payment systems such as PayPal, pay online system, Web Money and others. Details of information sought from shopper vary from one payment gateway to another.for example, payment website requires Personal Identification Number (PIN) when paying using debit card whereas shopping in Flip kart or Snap deal requires Visa or Master secure code.in addition to that merchant may require a Card Verification Value code, CVV which is basically an authorizing code in CNP transactions. According to the PCI Data Security Standard, merchants are prohibited from storing CVV information or PIN data and if permitted card information such as name card number and expiration date is stored, certain security standards are required.however recent high profile breaches such as in Network and Heartland Payment Systems show that card holders information is at risk both from outside and inside. A solution can be forcing merchant to be a PCI complaint but cost to be a PCI complaint is huge and the process is complex and time consuming and it will solve part of the problem. One still has to trust the merchant and its employees not to use card information for their own purposes Proposed Payment Method: In the proposed solution, information submitted by the customer to the online merchant is minimized by providing only minimum information that will only verify the payment made by the said customer from its bank account. This is achieved by the introduction of a central Certified Authority (CA) and combined application of steganography and visual cryptography. The information received by the merchant can be in the form of account number related to the card used for shopping. Information will only validate receipt of payment from authentic customer. The process is shown in Fig.1.2 (b).in the proposed method, customer unique authentication password in connection to the bank is hidden inside a cover text using the text based steganography method. Customer authentication information (account no) in connection with merchant is placed above the cover text in its original form. Now a snapshot of two texts is taken. From the snapshot image, two shares are generating using visual cryptography.it one share is kept by the customer and the other share is kept in the database of the certified authority. During shopping online, after selection of desired item and adding it to the cart, preferred payment system of the merchant directs the customer to the Certified Authority portal. In the portal, shopper submits its own share and merchant submits its own account details. Now the CA combines its own share with shopper s share and obtains the original image. From CA now, merchant account details, cover text are sent to the bank where customer authentication password is recovered from the cover text. Customer authentication information is sent to the merchant by CA. Upon receiving customer authentication password, bank matches it with its own database and after verifying legitimate customer, transfers fund from the customer account to the submitted merchant account. After receiving the fund, merchant s payment system validates receipt of payment using customer authentication information. 392 Copyright Vandana Publications. All Rights Reserved.

3 II. CRYPTOGRAPHY 2.1 Cryptography: Cryptography can be defined as the processing of information into an unintelligible (encrypted) form for the purposes of secure transmission. Through the use of a key the receiver can decode the encrypted message (decrypting) to retrieve the original message.the earliest forms of information hiding can actually be considered to be highly crude forms of private-key cryptography; the key in this case being the knowledge of the method being employed (security through obscurity). Greek messengers had messages tattooed into their shave head, concealing the message when their hair finally grew back. Wax tables were scraped down to bare wood were a message was scratched. Once the tablets were rewaxed, the hidden message was secure. Over time these primitive cryptographic techniques improved, increasing speed, capacity and security of the transmitted message. Today, crypto-graphical techniques have reached a level of sophistication such that properly encrypted communications can be assumed secure well beyond the useful life of the information transmitted. In fact, it s projected that the most powerful algorithms using multi kilobit key lengths could not be comprised through brute force, even if all the computing power worldwide for the next 20 years was focused on the attack. Of course the possibility exists that vulnerabilities could be found, or computing power breakthroughs could occur, but for most users in most applications, current cryptographic techniques are generally sufficient. Cryptography is the science of using mathematics to encrypt and decrypt data. Cryptography enables to store sensitive information or transmit it across insecure networks (like the Internet) so that it cannot be read by anyone except the intended recipient. While cryptography is the science of securing data, cryptanalysis is the science of analyzing and breaking secure communication. Classical cryptanalysis involves an interesting combination of analytical reasoning, application of mathematical tools, pattern finding, patience, determination, and luck. Cryptanalysts are also called attackers. Cryptology embraces both cryptography and cryptanalysis. Another advantage hinted at by is that information hiding can fundamentally change the way that it will think about information security. Cryptographic techniques generally rely on the metaphor of a piece of information being placed in a secure box and locked with a key. The information itself is not disturbed and anyone with the proper key can gain access. Once the box is open, all of the information security is lost. Compare this to information hiding techniques where the key is embedded into the information itself. 2.2 Stegaography: Steganography is the art of hiding information in ways that prevent the detection of hidden messages. Steganography comes from Greek and means covered writing. The ancient Greeks wrote text on wax-covered tablets. To pass a hidden message, a person would scrape off the wax and write the message on the underlying wood. it would then once again cover the wood with wax so it appeared unused. Many developments in steganography occurred during World War II. This included the development of invisible inks, microdots, and encoded messages. Steganography means to hide secret information into innocent data. Digital images are ideal for hiding secret information. An image containing a secret message is called a cover image. First, the difference of the cover image and the stego image should be visually unnoticeable. The embedding itself should draw no extra attention to the stego image so that no hackers would try to extract the hidden message illegally. Second, the message hiding method should be reliable. It is impossible for someone to extract the hidden message if she/he does not have a special extracting method and a proper secret key. Third, the maximum length of the secret message that can be hidden should be as long as possible. Stenography improves on this by hiding the fact that a communication even occurred. The message m is imbedded into a harmless message c which is defined as the cover-object. The message m is then embedded into c, generally with use of a key k that is defined as the stego-key. The resulting message is then embedded into the cover-object c, which results in segos-object s. 2.3 Steganography in the Digital Age: Steganography is the art of secret communication. Its purpose is to hide the very presence of communication as opposed to cryptography whose goal is to make communication unintelligible to those who do not possess the right keys. Digital images, videos, sound files, and other computer files that contain perceptually irrelevant or redundant information can be used as covers or carriers to hide secret messages. After embedding a secret message into the cover-image, a so-called stego-image is obtained. It is important that the stego-image does not contain any easily detectable artifacts due to message embedding. A third party could use such artifacts as an indication that a secret message is present. Once this message detection can be reliably achieved, the steganographic tool becomes useless. Another important factor is the choice of the cover-image. The selection is at the discretion of the person who sends the message. The sender should avoid using cover-images that would be easy to analyze for presence of secret messages. For example, one should not use computer art, charts, images with large areas of uniform color, images with only a few colors, and images with a unique semantic content, such as fonts. Although computer-generated fractal images may seem as good covers 6 because of their complexity and irregularity, they are generated by strict deterministic rules that may be easily violated by message embedding. 2.4 Cryptography VS Steganography: 393 Copyright Vandana Publications. All Rights Reserved.

4 Cryptography is the science of encrypting data in such a way that nobody can understand the encrypted message, whereas in steganography the existence of data is conceived means its presence cannot be noticed. The information to be hidden is embedded into the cover object which can be text, image, audio or video so that the appearance of cover object doesn t vary even after the information is hidden. Information to be hidden + cover object = stego object To add more security the data to be hidden is encrypted with a key before embedding. To extract the hidden information one should have thekey.a stego object is one, which looks exactly same as cover object with hidden information. 2.5 Steganography VS Watermarking: Watermarking is another branch of steganography it is mainly used to restrict the piracy in digital media. In steganography the data to be hidden is not at all related to the cover object, here our main intention is secret communication. In watermarking the data to be hidden is related to the cover object it is extended data or attribute of the cover object, here our main intention is to stop piracy of digital data. Steganography is a very powerful tool because, as the stated above, it can be very difficult to detect. 2.6 Stegosystem: Fig 2.6 (a): Stegosystems emb: The message to be embedded. It is anything that can be represented as a bit stream (an image or text). Cover: Data/Medium in which emb will be embedded. Stego: Modified version of the cover that contains the embedded message, emb. Key: Additional data that is needed for embedding & extracting. FE: Steganographic function that has cover, emb & key as parameters. Here is a graphical version of the stegosystem: Fig 2.6 (b): Graphical Versions of the Geo Systems Steganography refers to the science of invisible communication. Unlike cryptography, where the goal is to secure communications from an eavesdropper, steganographic techniques strive to hide the very presence of the message itself from an observer. It should be noted that the main goal of steganography is to communicate securely in a completely undetectable manner. That is, Wendy should not be able to distinguish in any sense between coverobjects (objects not containing any secret message) and stego-objects (objects containing a secret message). In 394 Copyright Vandana Publications. All Rights Reserved.

5 this context, steganalysis refers to the body of techniques that are designed to distinguish between cover-objects and stego-objects. It should be noted that nothing might be gleaned about the contents of the secret message. When the existence of hidden message is known, revealing its content is not always necessary. Although we focus on images, the general techniques would also be applicable to audio and video media. Given the proliferation of digital images, and given the high degree of redundancy present in a digital representation of an image (despite compression), there has been an increased interest in using digital images as cover-objects for the purpose of steganography. The simplest of such techniques essentially embeds the message in a subset of the LSB (least significant bit) plane of the image, possibly after encryption. It is well known that an image is generally not visually affected when its least significant bit plane is changed. Popular steganographic tools based on LSB like embedding vary in their approach for hiding information. Instead, most work has focused on analyzing or evaluating the watermarking algorithms for their robustness against various kinds of attacks that try to remove or destroy them. However, if robust digital watermarks are to be used in active warden steganography applications, detection of their presence by an unauthorized agent defeats their very purpose. Even in applications that do not require hidden communication, but only robustness, we note that it would be desirable to first detect the possible presence of a watermark before trying to remove or manipulate it. III. WAVELET TRANSFORM 3.1 Wavelet Transform: Wavelets are mathematical functions defined over a finite interval and having an average value of zero that transform data into different frequency components, representing each component with a resolution matched to its scale. The basic idea of the wavelet transform is to represent any arbitrary function as a superposition of a set of such wavelets or basis functions. These basis functions or baby wavelets are obtained from a single prototype wavelet called the mother wavelet, by dilations or contractions (scaling) and translations (shifts). They have advantages over traditional Fourier methods in analyzing physical situations where the signal contains discontinuities and sharp spikes. Many new wavelet applications such as image compression, turbulence, human vision, radar, and earthquake prediction are developed in recent years. In wavelet transform the basic functions are wavelets. Wavelets tend to be irregular and symmetric. All wavelet functions, w (2kt - m), are derived from a single mother wavelet, w (t). This wavelet is a small wave or pulse like the one shown in Fig. 3.1 Normally it starts at time t = 0 and ends at t = T. The shifted wavelet w (t - m) starts at t = m and ends at t = m + T. The scaled wavelets w (2kt) start at t = 0 and end at t = T/2k. Their graphs are w (t) compressed by the factor of 2k as shown in Fig 3.2.For example, when k = 1, the wavelet is shown in Fig 3.2 (a). If k = 2 and 3, they are shown in fig 3.2 (b) and (c), respectively. The wavelets are called orthogonal when their inner products are zero. The smaller the scaling factor is, the wider the wavelet is. Wide wavelets are comparable to low-frequency sinusoids and narrow wavelets are comparable to high-frequency sinusoids. 395 Copyright Vandana Publications. All Rights Reserved. IV. IMAGE EMBEDDING DATA Two files are required when one wishes to hide data inside of another file. The first file required is the image that will contain the hidden information. This file is called the cover image. The second file required is the message file that contains the information that needs to be concealed. This hidden message can come in a number of different formats such as: plain text, ciphertext, other images, or anything that can be embedded in a bit stream (i.e. 1 s and 0 s). A private-key (used as password to unlock the hidden data) may also be used to hide, and then later decode, the message. Most software available today neither support nor recommend jpeg images, but recommends instead the use of 24-bit images such as BMP. The next-best alternative to 24-bitimages is to use 256-color or gray-scale images for embedding the hidden message into. GIF files are 8 bit color images where each pixel is represented as a single byte, and each pixel is used as appointer to a color index table (a palette) with 256 possible colors. The pixel s value, then, is between0 and 255. The software simply paints the indicated color on the screen at the selected pixel position. The images of choice by many steganography experts are images featuring 256 shades of gray. These gray-scale images are preferred because the shades change very gradually from byte to byte, and the less the value changes between palette entries, the less noticeable image color variation are. Information can be hidden

6 many different ways in images. To hide information, straight message insertion may encode every bit of information in the image or selectively embed the message in noisy areas that draw less attention those areas where there is a great deal of natural color variation. The message may also be scattered randomly throughout the image. Redundant pattern encoding wallpapers the cover image with the message. V. ALGORITHM Step 1: Let the cover image is represented by c(x, y). It is then passed through a filter with transfer function h(x, y) to separate high and low frequency components. F[c(x, y)] = C(X, Y) Where C(X, Y) represents Fourier Transform of the cover image. In this paper capital letters representation for pixel is used for frequency domain and small letters for spatial representation. C(X, Y) H(X, Y) = LO(X, Y) + HI(X, Y) Where LO(X, Y), HI(X, Y) represent low frequency and high frequency components of cover image respectively, obtained after passing through the filter with cut off as stated above. Step 2: Inverse transform of both the frequency components is found out, known as HFSI (High Frequency components Spatial Image) and LFSI (Low Frequency components Spatial Image) separately. F 1[LO(X, Y)]= lo(x, y) and F-1 [HI(X, Y)] = hi(x, y) Where lo (x, y) and hi(x, y) are the spatial components of low and high frequencies in the cover image respectively. Step 3: Now message is embedded into HFSI image. The number of bits modified in a pixel is made to depend up on its magnitude and also on the local features of the cover image. Let the message is represented as m(x,y) and the embedding function as M[]. Mhi(x, y) = M [hi(x, y) + m(x, y)] Step 4: Both the modified HFSI and unmodified LFSI are added to form stego image. Steg(x, y) = mhi(x, y) + lo(x, y) Step5: At the receiver LFSI is subtracted from stego image leaving modified HFSI image. Mhi(x, y) = steg(x, y) lo(x, y) Step 6: Now the message is decoded from the Modified HTSI image using the stego key m(x, y) + hi(x, y) = M [mhi(x, y)] 5.1 Flowchart for Steganography: 396 Copyright Vandana Publications. All Rights Reserved.

7 VI. 1. Runs the program. SIMULATION RESULTS 2. First we can run the steganography program on the mat lab software. 3. It will click the cover image in the input panel 4. Next it will select the cover image from another folder 5. And after that it will click password file in the input file 6. Select the secret data in the input panel. 397 Copyright Vandana Publications. All Rights Reserved.

8 7. Saves the secret data is completed successfully 8. It will click on the embed and after that embed process is completed successfully 9. It will run the steganography program in the mat lab software. After that click on the secret image 398 Copyright Vandana Publications. All Rights Reserved.

9 10. Secret image is selected by another folder 11. Secret image is created by using steganography 12. It will click the cover object Copyright Vandana Publications. All Rights Reserved.

10 13. It will select the cover object1 into another folder. 14. Cover object1 is created on bank copy 15. It will select a another cover object2 into a another folder 16. Next another cover object2 is created.and after that encoding will start in the process 400 Copyright Vandana Publications. All Rights Reserved.

11 17. Show the encoding process is completed 18. Same like that also decoding will start and after that decoding process is completed 19. Next it will click the extraction process is created and after that it will extraction process is completed 20. Finally the output is created and saves. 401 Copyright Vandana Publications. All Rights Reserved.

12 VII. ADVANTAGES Proposed method minimizes customer information sent to the online merchant. So in case of a breach in merchant s database, customer doesn t get affected. It also prevents unlawful use of customer information at Merchant s side. Usage of steganography ensures that the CA does not know customer authentication password thus maintaining customer privacy. Cover text can be sent in the form of from CA to bank to avoid suspension rising. VIII. CONCLUSION In this paper, a payment system for online shopping is proposed by combining text based steganography and visual cryptography that provides customer data privacy and prevents misuse of data at merchant s side. The method is concerned only with prevention of identity theft and customer data security. In comparison to other banking application which uses steganography and visual cryptography, are basically applied for physical banking, the proposed method can be applied for E-Commerce with focus area on payment during online shopping as well as physical banking. IX. FUTURE SCOPE The payment system can also be extended to physical banking. Shares may contain customer image or signature in addition to customer authentication password. In the bank, customer submits its own share and customer physical signature is validated against the signature obtained by combining customer s share and CA s share along with validation of customer authentication password. It prevents misuse of stolen card and stops illegitimate customer. REFERENCES [1]. Jihui Chen, Xiaoyao Xie, and FengxuanJing, "The security of shopping online [2]. Javelin Strategy & Research, 2013 Identify Fraud Report. [3]. Anti-Phishing Working Group (APWG), Phishing Activity Trends Report. [4]. Jack Brassil, Steven Low, Nicholas Maxemchuk, Larry O Gorman, Hiding Information in Document Images, [5]. J. Chen, T. S. Chen, M. W. Cheng, A New Data Hiding Scheme in Binary Image,. [6]. Hu ShengDun, U. KinTak, A Novel Video Steganography Based on Non-uniform Rectangular Partition, [7]. Daniel Gruhl, Anthony Lu, Walter Bender, Echo Hiding. [8]. Chetana Hegde, S. Manu, P. Deepa Shenoy,K.R.Venugopal, LM Patnaik, Secure Authentication using Image Processing and Visual Cryptography for Banking Applications. 402 Copyright Vandana Publications. All Rights Reserved.