International Journal of Electronic Security and Digital Forensics (3 papers in press)

• A new spread spectrum watermarking method using two levels DCT
  by Amirhossein Taherinia, Mansour Jamzad 
  Abstract: In this paper, a DCT-based blind watermarking scheme based on spread spectrum communications is proposed. We perform block-based DCT on the host image; then using the DC coefficients of each block, we construct a low-resolution approximation image. We apply block-based DCT on this approximation image, then watermark is embedded by adding a pseudo random noise sequence into its high frequencies. In detection stage, we extract the approximation image from the watermarked image, then the same pseudo random noise sequence is generated, and its correlation is computed with high frequencies of the watermarked approximation image. In our method, higher robustness is obtained because of embedding the watermark in low frequencies. In addition, higher imperceptibility is gained by scattering the watermark’s bit in different blocks. Compared with related works, our method proved to be highly resistant in cases of many common attacks, while preserving high PSNR for the watermarked images.
  Keywords: blind digital watermarking; DCT; spread spectrum watermarking.
   
• Improved wireless security for GMSK-based devices using RF fingerprinting
  by Donald Reising, Michael Temple, Michael Mendenhall 
  Abstract: Gaussian Minimum Shift Keying (GMSK) is widely employed and remains a mainstay modulation technique for future wireless systems. This work addresses physical layer (PHY) security using RF fingerprints from GMSK-based signals to thwart malicious activities that are commonly orchestrated through unauthorized use of digital identities. Global System for Mobile (GSM) communications are GMSK-based systems that support over 80% of worldwide mobile users who remain greatly exposed to security risks. GSM-GMSK is used here for RF fingerprinting proof-of-concept demon-stration with a goal of classifying specific hardware devices with such accuracy that authorized and unauthorized users are distinguishable. Using RF fingerprints from near-transient and midamble regions of GSM-GMSK bursts, Multiple Discriminant Analysis with Maximum Likelihood (MDA/ML) classification is performed and performance compared. While midamble classification performance using instantaneous phase responses is notable, results using GSM-GMSK near-transient features are 12% better at SNR = 20 dB and accuracies of 88%-94% are achieved at SNR = 6 dB. While transient feature performance is consistent with previous 802.11a results, midamble performance is poorer and various factors are identified as potential contributors to the increased classification challenge posed by GMSK signals.
  Keywords: wireless security; GMSK; RF fingerprinting; specific emitter identification; SEI; multiple discriminant analysis; PHY layer; authentication
   
• A New Methodology for Data Coding and Embedding for High Capacity Transmitting
  by Rajesh Tiwari, G Sahoo 
  Abstract: The rapid development of internet opened up unlimited opportunities in the field of computing. However, it brought about a plethora of new issues and concerns, chief among them is the security of information that to be exchanged. Developing information hiding techniques has seriously been taken by many researchers, steganography, the science of embedding secret information into carrier image file, is one of the main concern. In the current digital era, the steganographic methods may participate in the field of ultra wideband wireless communication, but, the major the hurdles is the pre-existing carrier with low embedding capacity. If we create the carrier file based on the transmitting message that will help us in two aspects, first it saves the bandwidth and second it maintains the utmost security as well. Unlike the other steganographic efforts where data embedding in carrier file works in the principle of pre-existing carrier file, we propose here a method that works on the principle of creating its own carrier file based on the transmitting message. The major advantage of this approach is that there is never a mother carrier file created or exits in order to give a chance to other concerned to suspect the hiding of any secret file and at the same time we utilize the minimum bandwidth with maximum security protection.
  Keywords: Steganography; Stego-Image; Cover Medium; Stego-key; Carrier file