An image encryption algorithm robust to post-encryption bitrate conversion

Akdağ, Sadık Bahaettin
In this study, a new method is proposed to protect JPEG still images through encryption by employing integer-to-integer transforms and frequency domain scrambling in DCT channels. Different from existing methods in the literature, the encrypted image can be further compressed, i.e. transcoded, after the encryption. The method provides selective encryption/security level with the adjustment of its parameters. The encryption method is tested with various images and compared with the methods in the literature in terms of scrambling performance, bandwidth expansion, key size and security. Furthermore this method is applied to the H.263 video sequences for the encryption of I-frames.


A Cascadable Random Neural Network Chip with Reconfigurable Topology
Badaroglu, Mustafa; Halıcı, Uğur; Aybay, Isik; Cerkez, Cuneyt (Oxford University Press (OUP), 2010-03-01)
A digital integrated circuit (IC) is realized using the random neural network (RNN) model introduced by Gelenbe. The RNN IC employs both configurable routing and random signaling. In this paper we present the networking/routing aspects as well as the performance results of an RNN network implemented by the RNN IC. In the RNN model, each neuron accumulates arriving signals and can fire if its potential at a given instant of time is strictly positive. Firing occurs at random, the intervals between successive ...
A reality check for radiometric camera response recovery algorithms
Akyüz, Ahmet Oğuz (Elsevier BV, 2013-11-01)
The radiometric response of a camera governs the relationship between the incident light on the camera sensor and the output pixel values that are produced. This relationship, which is typically unknown and nonlinear, needs to be estimated for applications that require accurate measurement of scene radiance. Until now, various camera response recovery algorithms have been proposed each with different merits and drawbacks. However, an evaluation study that compares these algorithms has not been presented. In...
A compact cryptographic processor for IPSec applications
Kavun, Elif Bilge; Akyıldız, Ersan; Yalçın, Tolga; Department of Cryptography (2010)
A compact cryptographic processor with custom integrated cryptographic coprocessors is designed and implemented. The processor is mainly aimed for IPSec applications, which require intense processing power for cryptographic operations. In the present design, this processing power is achieved via the custom cryptographic coprocessors. These are an AES engine, a SHA-1 engine and a Montgomery modular multiplier, which are connected to the main processor core through a generic flexible interface. The processor ...
An FPGA implementation of real-time electro-optic & IR image fusion
Çölova, İbrahim Melih; Akar, Gözde; Department of Electrical and Electronics Engineering (2010)
In this thesis, a modified 2D Discrete Cosine Transform based electro-optic and IR image fusion algorithm is proposed and implemented on an FPGA platform. The platform is a custom FPGA board which uses ALTERA Stratix III family FPGA. The algorithm is also compared with state of the art image fusion algorithms by means of an image fusion software application GUI developed in Matlab®. The proposed algorithm principally takes corresponding 4x4 pixel blocks of two images to be fused and transforms them by means...
A Greedy Link Scheduler for Wireless Networks With Gaussian Multiple-Access and Broadcast Channels
Sridharan, Arun; Koksal, C. Emre; Uysal, Elif (Institute of Electrical and Electronics Engineers (IEEE), 2012-02-01)
Information-theoretic broadcast channels (BCs) and multiple-access channels (MACs) enable a single node to transmit data simultaneously to multiple nodes, and multiple nodes to transmit data simultaneously to a single node, respectively. In this paper, we address the problem of link scheduling in multihop wireless networks containing nodes with BC and MAC capabilities. We first propose an interference model that extends protocol interference models, originally designed for point-to-point channels, to includ...
Citation Formats
S. B. Akdağ, “An image encryption algorithm robust to post-encryption bitrate conversion,” M.S. - Master of Science, Middle East Technical University, 2006.