89 research outputs found

    Covert Voice over Internet Protocol communications based on spatial model

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    This paper presents a new spatial steganography model for covert communications over Voice over Internet Protocol (VoIP), providing a solution to the issue of increasing the capacity of covert VoIP channels without compromising the imperceptibility of the channels. Drawing from Orthogonal Modulation Theory in communications, the model introduced two concepts, orthogonal data hiding features and data hiding vectors, to covert VoIP communications. By taking into account the variation characteristics of VoIP audio streams in the time domain, a hiding vector negotiation mechanism was suggested to achieve dynamic self-adaptive ste-ganography in media streams. Experimental results on VoIP steganography show that the pro-posed steganographic method effectively depicted the spatial and temporal characteristics of VoIP audio streams, and enhanced robustness against detection of steganalysis tools, thereby improving the security of covert VoIP communications

    Audio Steganography using Modified Enhanced Least Significant Bit in 802.11n

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    Steganography is a technique to improve the security of data, which is by inserting messages or confidential information using a medium called the host or carrier or cover. A wide variety of digital media can be used as a host, among others audio, image, video, text, header, IP datagram, and so forth. For audio steganography, the embedded audio is called stego-audio. Steganography can be cracked by using steganalysis. By exploiting the weaknesses of each steganography method. Many steganography method has been developed to increase its performance. This Thesis proposed audio steganography scheme called MELSB which is modified version of ELSB. This method using Modified Bit Selection Rule to increase SNR and robustness of stego-audio. SNR result after applying MELSB scheme is increased. MELSB scheme also increase robustness of stego-audio. MELSB still work fine until amplification level 1.07. MELSB also work fine against noise addition better than ELSB and LSB. It give BER and CER with value 0 at SNR 33 dB. MELSB work fine in real-time condition on 802.11n WLAN if there is no transcoding and noise addition between sender’s and recipient’s compute

    Covert communication over VoIP streaming media with dynamic key distribution and authentication

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    Voice over Internet Protocol (VoIP) is widely embedded into commercial and industrial applications. VoIP streams can be used as innocuous cover objects to hide the secret data in steganographic systems. The security offered by VoIP signaling protocols is likely to be compromised due to a sharp increase in computing power. This article describes a theoretical and experimental investigation of covert steganographic communications over VoIP streaming media. A new information-theoretical model of secure covert VoIP communications was constructed to depict the security scenarios in steganographic systems against the passive attacks. A one-way accumulation-based steganographic algorithm was devised to integrate dynamic key updating and exchange with data embedding and extraction, so as to protect steganographic systems from adversary attacks. The theoretical analysis of steganographic security using information theory proves that the proposed model for covert VoIP communications is secure against a passive adversary. The effectiveness of the steganographic algorithm for covert VoIP communications was examined by means of performance and robustness measurements. The results reveal that the algorithm has no or little impact on real-time VoIP communications in terms of imperceptibility, speech quality, and signal distortion, and is more secure and effective at improving the security of covert VoIP communications than the other related algorithms with the comparable data embedding rates

    Self-Verification Of Public-Key Agreement Over Voip Using Random Fusion Scheme

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    Telefoni Internet, yang dikenali juga sebagai Suara melalui Protokol Internet (VoIP), menjadi salah satu alternatif telekomunikasi yang popular disebabkan penggunaan Internet yang semakin meluas. Internet memperkaya cara sistem telefoni digunakan, tetapi dalam masa yang sama menimbulkan pelbagai kebimbangan, terutamanya keselamatan Internet telephony, also known as Voice over Internet Protocol (VoIP), has become one of popular alternatives in telecommunication due to the widespread of the Internet usage. The Internet enriches the way of telephony system is used, but in the meantime it elevates many concerns, particularly security

    SkypeMorph: Protocol Obfuscation for Censorship Resistance

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    The Tor network is designed to provide users with low-latency anonymous communication. Tor clients build circuits with publicly listed relays to anonymously reach their destinations. Low-latency anonymous communication is also an essential property required by censorship circumvention tools and thus Tor has been widely used as a censorship resistance tool. However, since the Tor relays are publicly listed, they can be easily blocked by censoring adversaries. Consequently, the Tor project envisioned the possibility of unlisted entry points to the Tor network, commonly known as bridges. In recent years, there have been attempts to achieve fast and real-time methods to discover Tor, and specifically bridge, connections. In this thesis we address the issue of preventing censors from detecting a certain type of traffic, for instance Tor connections, by observing the communications between a remote node and nodes in their network. We propose a generic model in which the client obfuscates its messages to the bridge in a widely used protocol over the Internet. We investigate using Skype video calls as our target protocol and our goal is to make it difficult for the censoring adversary to distinguish between the obfuscated bridge connections and actual Skype calls using statistical comparisons. Although our method is generic and can be used by any censorship resistance application, we present it for Tor, which has well-studied anonymity properties. We have implemented our model as a proof-of-concept proxy that can be extended to a pluggable transport for Tor, and it is available under an open-source licence. Using this implementation we observed the obfuscated bridge communications and showed their characteristics match those of Skype calls. We also compared two methods for traffic shaping and concluded that they perform almost equally in terms of overhead; however, the simpler method makes fewer assumptions about the characteristics of the censorship resistance application’s network traffic, and so this is the one we recommend

    Enhanced LSB Algorithm For Stegano Communication

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    Steganography is outlined because the study of invisible communication that typically deals with the ways that of concealing the existence of the communicated message. Usually, information embedding is achieved in communication, image, text, voice or transmission content for copyright, military communication, authentication and plenty of alternative functions. In image Steganography, secret communication is achieved to infix a message into cowl image and generate a stego image. The goal of steganography is to cover the existence of the message from unauthorized party. The fashionable secure image steganography presents a task of transferring the embedded data to the destination while not being detected by the attacker. Several different image file formats will be used, however, digital pictures area unit the foremost widespread owing to their frequency on the web. Image steganography takes cover object as image. Generally, in this technique pixel intensities are used to hide the information. The concept of steganography known as ‘Enhanced LSB Algorithm’ is employed to hide an image in an image, which has negligent distortion as compared to the Least Significant Bit Algorithm
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