1. STEGANOGRAPHY USING GENETIC ALGORITHM ALONG WITH VISUAL CRYPTOGRAPHY FOR WIRELESS NETWORK APPLICATION Seminar Report Submitted in partial fulfillment of the requirements For the award of the Degree in Master of Computer Applications From University of Kerala By APARNA N K DEPARTMENT OF COMPUTER APPLICATIONS MOHANDAS COLLEGE OF ENGINEERING & TECHNOLOGY Anad, Nedumangadu, Thiruvananthapuram-695544 2014
2. Steganography 2 Dept.of ComputerApplications MOHANDAS COLLEGE OF ENGINEERING & TECHNOLOGY Anad, Nedumangadu, Thiruvananthapuram-695544 This is to certify that this is a bonafide report of the seminar presented by Ms. Aparna N K (Roll No. 1) in partial fulfillment of the requirements for the award of the degree in MASTER OF COMPUTER APPLICATIONS by the University of Kerala. Date Staff In charge Ms. JeejaG.S Asst.professor Dept of Computer Applications
3. Steganography 3 Dept.of ComputerApplications ACKNOWLEDGEMENT I am greatly thankful to Ms. Sreeja K.( Head of the Department) and Ms. Jeeja G S (Asst.professor, Department of Computer Applications) for their kind co-operation for presenting the seminar. I also extend my sincere thanks to all other faculty members of Department of Computer Applications and my friends for their co-operation and encouragements. Last but not the least I would like the GOD almighty for helping me to complete my seminar on time. APARNA N K
5. Steganography 5 Dept.of ComputerApplications Synopsis Image steganography is an emerging field of research for secure data hiding and transmission over networks. The proposed systemprovides the best approach for Least SignificantBit (LSB) based steganography using Genetic Algorithm (GA)along with Visual Cryptography (VC). Original message isconverted into cipher text by using secret key and then hiddeninto the LSB of original image. Genetic Algorithm and VisualCryptography has been used for enhancing the security. GeneticAlgorithm is used to modify the pixel location of stego image andthe detection of this message is complex. Visual Cryptography isused to encrypt the visual information. It is achieved by breakingthe image into two shares based on a threshold.The main aim is to design theenhanced secure algorithm which uses both steganography using Genetic Algorithm and Visual Cryptography to ensure improved security and reliability.
6. Steganography 6 Dept.of ComputerApplications 1. Introduction Hiding information by embedding secret data into aninnocuous medium is often referred to as steganography.Steganography can be applied electronically by taking amessage (a binary file) and some sort of cover (often a soundor image file) and combining both to obtain a stego-object. The rapid development of data transfer through internet made it easier to send the data accurate and faster to the destination. One of the most important factors of information technology and communication has been the security of the information. For security purpose the concept of Steganography is being used. Steganography is art and science of invisible communication.The steganalysis algorithm which we used here has the potential to detect thehidden message by the statistic analysis of pixel values . The use of steganography in combination visual cryptographyis a sturdy model and adds a lot of challenges to identifyingsuch hidden and encrypted data.
7. Steganography 7 Dept.of ComputerApplications 2. Concepts and principles 2.1 Steganography Steganography is the technique of hiding confidential information within any media. Steganography is often confused with cryptography because the two are similar in the way that they both are used to protect confidential information. The difference between the two is in the appearance in the processed output; the output of steganography operation is not apparently visible but in cryptography the output is scrambled so that it can draw attention. Steganography today, however, is significantly more sophisticated than the examples above suggest, allowing a user to hide large amounts of information within image and audio files. These forms of steganography often are used in conjunction with cryptography so that the information is doubly protected; first it is encrypted and then hidden so that an adversary has to first find the information (an often difficult task in and of itself) and then decrypt it. The following formula provides a very generic description of the pieces of the steganographic process: Cover medium + hidden data + stego key = stego medium
8. Steganography 8 Dept.of ComputerApplications Block diagram of steganography and data transmission 2.2 Steganalysis: The detection of steganographically encoded packages is called Steganalysis. To make steganalysis easier, several softwares are readily available on the internet as freeware or as a shareware. These softwares are capable of determining the irregularity of RGB patterns in the image, thus alerting the user that the particular image is a stego image. Steganalysis is the study of detecting messages hidden using steganography; this is analogous to cryptanalysis applied to cryptography. he goal of steganalysis is to identify suspected packages, determine whether or not they have a payload encoded into them, and, if possible, recover that payload. Based on whether an image contains hidden message, images can be classified into two classes: the image with no hidden message and the corresponding stego-image (the very image but with message hidden in it). Steganalysis can thus be considered as a pattern recognition process to decide which class a test image belongs to. The key issue for steganalysis just like for pattern recognition is feature extraction. The features should be sensitive to the data hiding process. In other words, the features should be rather different for the image without hidden message and for the stego-image.
9. Steganography 9 Dept.of ComputerApplications 2.3 Cryptography Cryptography is the practice and study of techniques for secure communication in the presence of third parties (called adversaries). Cryptography is a cornerstone of the modern electronic security technologies used today to protect valuable information resources on intranets, extranets, and the Internet. . Cryptography is the science of writing in secret code and is an ancient art; the first documented use of cryptography in writing dates back to circa 1900 B.C. when an Egyptian scribe used non-standard hieroglyphs in an inscription. Some experts argue that cryptography appeared spontaneously sometime after writing was invented, with applications ranging from diplomatic missives to war-time battle plans. It is no surprise, then, that new forms of cryptography came soon after the widespread development of computer communications. In data and telecommunications, cryptography is necessary when communicating over any untrusted medium, which includes just about any network, particularly the Internet. Cryptography, then, not only protects data from theft or alteration, but can also be used for user authentication. There are, in general, three types of cryptographic schemes typically used to accomplish these goals: secret key (or symmetric) cryptography, public-key (or asymmetric) cryptography, and hash functions, each of which is described below. In all cases, the initial unencrypted data is referred to plaintext. It is encrypted into ciphertext, which will in turn (usually) be decrypted into usable plaintext.
10. Steganography 10 Dept.of ComputerApplications 2.4 Genetic Algorithm In the computer science field of artificial intelligence, a genetic algorithm (GA) is a search heuristic that mimics the process of natural selection. This heuristic (also sometimes called a metaheuristic) is routinely used to generate useful solutions to optimization and search problems. A genetic algorithm is one of a class of algorithms that searches a solution space for the optimal solution to a problem. This search is done in a fashion that mimics the operation of evolution - a "population" of possible solutions is formed, and new solutions are formed by "breeding" the best solutions from the population's members to form a new generation. The population evolves for many generations; when the algorithm finishes the best solution is returned. Genetic algorithms are particularly useful for problems where it is extremely difficult or impossible to get an exact solution, or for difficult problems where an exact solution may not be required. They offer an interesting alternative to the typical algorithmic solution methods, and are highly customizable, which make them an interesting challenge for students.
11. Steganography 11 Dept.of ComputerApplications 2. LSB algorithm 2.1 About LSB algorithm The proposed scheme uses RSA or Diffie Hellman algorithm to encrypt secret information. To provide higher security the secret information is encrypted first and encrypted ASCII value is converted in binary form. In this method the least significant bits of some or all of the bytes inside an image is replaced with a bits of the secret message. The image is now used as a cover to embed the encrypted information. The Least Significant Bit algorithm is faster and reliable and compression ratio is moderate compared to other algorithms. Sender Side