Subariah Ibrahim

Information hiding using steganography

Due to advances in ICT, most information is kept electronically. Consequently, the security of information has become a fundamental issue. Besides cryptography, steganography can be employed to secure information. Steganography is a technique of hiding information in digital media. In contrast to cryptography, the message or encrypted message is embedded in a digital host before passing it through the network, thus the existence of the message is unknown. Besides hiding data for confidentiality, this approach of information hiding can be extended to copyright protection for digital media: audio, video, and images.

Enhanced chaotic image encryption algorithm based on Baker's map

Imaging has gained importance due to the improvements of performances in computer speed, media storage and network bandwidth. Along with this advancement, the fundamental issue of image security has become a major concern and because of this reason, research in image confidentiality has gained popularity amongst security experts. This paper discusses an alternative chaotic image encryption based on Bakers map. This enhanced symmetric-key algorithm can support a variable-size image as opposed to the algorithm which is mainly based on Bakers map that requires only square image for encryption. In addition, the algorithm also includes other functions such as password binding and pixel shifting to further strengthen the security of the cipher image. The algorithm also supports two modes of operation namely EBC and CBC. The number of iterations to be performed can vary depending on the security level required by the user. The paper also includes an example of image encryption. From the analysis done, it shows that the security level is high even though keys that are found to be weak keys for Bakers map algorithm are being used in the algorithm.

Secure E-voting with blind signature

With a rapid growth in computer networks, many people can access the network through the Internet and therefore an electronic voting can be a viable alternative for conducting an election. An electronic voting system must attempt to achieve at least the same level of security as ordinary elections. We have developed an electronic voting system, E-voting for a general election. The E-voting system employs cryptographic techniques to overcome the security issues in the election process. In this system, voters privacy is guaranteed by using a blind signature for confidentiality and voters digital signature for voters authentication. E-voting is implemented by employing Java socket technology and BouncyCastle cryptography provider. The provider, which is an open source library, is used to provide the secure communication channel. The voters private key for digital signature is protected by using password-based encryption with SHA and Twofish-CBC algorithm so that only valid voter can use it.

Fast Algorithm for Iris Localization Using Daugman Circular Integro Differential Operator

The iris localization is a very important step for iris-recognition. In this step concentric circular outer boundaries of the iris and the pupil in eye’s image identify. We enhanced Daugman method to locate the iris by using an Average Square Shrinking Approach. The algorithm is tested using iris images from CASIA database and MMU database. The circle contour sampling parameter has been investigated to find a tradeoff between speed and accuracy of algorithm for different number of points on a circle. The experiments show proposed algorithm can localize the iris faster than other similar methods. Our approach is feasible for online authentication application that need more speed in detection.

Iris Biometric Cryptography for Identity Document

Currently, it is noticed that users tend to choose shorter password as their authentication which can be easily attacked. Biometric technologies such as fingerprint scanning, voice authentication, face recognition, signature, hand geometry and iris recognition is now playing an important role especially in application related to security issue. In this work, we present an approach to generate a unique and more secure cryptographic key from iris template. The iris images are processed to produce iris template or code to be utilized for the encryption and decryption tasks. AES cryptography algorithm are employed to encrypt and decrypt the identity data. Distance metric such as hamming distance and Euclidean distance are used for the template matching identification process. Experimental results show that this system can obtain a higher security with a low false rejection or false acceptance rate.

Adaptive steganography scheme using more surrounding pixels

Information hiding has several branches. One is called as steganography. Steganography has a wide variety of techniques whereby a certain amount of secret information is embedded inside a medium. The medium format can be of any kind. However, the simplest file format is an 8-bit gray scale image. The original image is called a cover image. Likewise, once some secret bits are embedded, it is called stego-image. The most challenging issue is how capable a technique is to conceal the very existence of secret information in the stego-image. Steganographic techniques are evaluated in terms of imperceptibility and capacity. Imperceptibility means how visible secret information is to the human eyes in the stego-image. On the other hand, capacity means the maximum amount of secret information embedded. Conventional Least Significant Bit (LSB) insertion method is the basic concept for steganographic techniques. LSB method embeds secret bits in LSB(s) of the cover image. A pixel which carries a fraction of secret data is called a target pixel. The more surrounding pixels around a target pixel are utilized to find the most appropriate capacity value, the more precise capacity value is achieved. This paper proves that discovering the best capacity value brings about an improvement in terms of imperceptibility. Most of the steganographic techniques use either three or four adjacent pixels around a target pixel whereas the proposed technique is able to utilize at most all eight adjacent neighbors so that imperceptibility value grows bigger. The proposed method is called A-MSPU which stands for Adaptive More Surrounding Pixels Using.

Error Correction on IRIS Biometric Template Using Reed Solomon Codes

Pin number or password that is used for authentication can be easily attacked. This limitation triggered the utilization of biometric for secured transactions. Biometric is unique to each individual and is reliable. Among the types of biometric being used currently, iris is the most accurate and it remains stable throughout a person’s life. However the major challenge on iris and other biometric for authentication is the intra user variability in the acquired identifiers. Iris of the same person captured at different time may differ due to the signal noise of the iris camera. Traditional cryptography method is unable to encrypt and store biometric template, then perform the matching directly. Minor changes in the bits of the feature set extracted from the iris may lead to a huge difference in the results of the encrypted feature. In our approach, an iris biometric template is secured using iris biometric and passwords. Error Correction Code, ECC is introduced to reduce the variability and noise of the iris data. Experimental results show that this approach can assure a higher security with a low false rejection or false acceptance rate. The successful iris recognition rate using this approach is up to 97%.

A new approach for relational database watermarking using image

Proving ownership rights on outsourced databases is a vital issue. This paper proposed an improved algorithm for database watermarking. In the experiment, we embed an image watermark into numerical attributes in a relational database. It refers to image elements as 2-dimention matrix elements and tries to embed medium size image in small scale relation. By applying this method we can obtain upper Correction Factor for image. Furthermore at the phase of embedding watermark, this algorithm is capable of minimizing data variation method which assures the minimum modification to original database without decreasing imperceptibility. In extracting process majority voting method is employed to get retrieve the correct watermark. To improve this process, recovering step is added to the extracting process. This step tries to recover extracted image and guess missing elements value, so the watermark can be detected even in a small subset of a watermarked database. Detecting the watermark neither requires the original database nor the watermark.

An enhanced SVD based watermarking using U matrix

Protecting images against illegal duplications is an important fact and recently many watermarking algorithms have been published. In this paper an enhanced SVD-based watermarking algorithm is proposed. In the proposed method U component is explored for embedding the watermark. Experimental results show that imperceptibility and robustness of the algorithm is good.

Image steganography based on adaptive optimal embedding

A real-life requirement motivated this case study of secure covert communication. Steganography is a technique used to transfer hidden information in an imperceptible manner. We proposed a novel approach of substitution technique of image steganography. The proposed method is completely flexible on size of secret message bits and allows us to embed a large amount of secret messages as well as maintaining good visual quality of stego-image. Using this method, message bits are embedded into uncertain and higher LSB layers, resulting in increased imperceptible and robustness of stego-image.