Challenges in the Implementation and Simulation for Wireless Side-Channel based on Intentionally Corrupted FCS

AbstractWe report on the challenges faced in the implementation and simulation of a side-channel communication based on frames with an intentionally corrupted Frame Check Sequence (FCS). Systematically corrupted FCSs can be used to enable covert communications between nodes that share the same algorithm for deciphering the FCS. In order to assess the possibility in detecting this side-channel communication it is necessary to have the ability to simulate it as well as to implement it on actual devices. Nearly all simulators drop corrupted frames before they reach their destination, making it impossible to simulate any side-channel communication based on intentionally corrupted FCS. We present an example of the modifications required to prevent this as applied to a well-known simulator called Sinalgo. We also discuss problems encountered when trying to intentionally corrupt the FCS on actual devices

Towards Unconditional Tor-Like Anonymity

We design and evaluate a traffic anonymization protocol for wireless networks, aiming to protect against computationally powerful adversaries. Our protocol builds on recent key-generation techniques, that leverage intrinsic properties of the wireless together with standard coding techniques. We show how to exploit the security properties of such keys to design a Tor-like anonymity network, without making any assumptions about the computational capabilities of an adversary. Our analysis and evaluation on simulated ad-hoc wireless networks, shows that our protocol achieves a level of anonymity comparable to the level of the Tor network

TOR - Didactic pluggable transport

Considering that access to information is one of the most important aspects of modern society, the actions of certain governments or internet providers to control or, even worse, deny access for their citizens/users to selected data sources has lead to the implementation of new communication protocols. TOR is such a protocol, in which the path between the original source and destination is randomly generated using a network of globally connected routers and, by doing so, the client is not identified as actually accessing the resource. However, if the ISP knows that the first hop is part of TOR or if it can identify the contents of the exchanged packages as being TOR packages, by using advanced detection algorithms, it can still perform it’s denial policies. These types of detection are circumvented by the usage of bridges (TOR routers which aren’t publicly known) and pluggable transports (content changing protocols, in order to pass through as innocent-looking traffic). The development of a didactic pluggable transport in a simulated TOR network is the main purpose of this paper, in order to investigate the current state of the art of TOR development and analysis

Private Communication Detection via Side-Channel Attacks

Private communication detection (PCD) enables an ordinary network user to discover communication patterns (e.g., call time, length, frequency, and initiator) between two or more private parties. Analysis of communication patterns between private parties has historically been a powerful tool used by intelligence, military, law-enforcement and business organizations because it can reveal the strength of tie between these parties. Ordinary users are assumed to have neither eavesdropping capabilities (e.g., the network may employ strong anonymity measures) nor the legal authority (e.g. no ability to issue a warrant to network providers) to collect private-communication records. We show that PCD is possible by ordinary users merely by sending packets to various network end-nodes and analyzing the responses. Three approaches for PCD are proposed based on a new type of side channels caused by resource contention, and defenses are proposed. The Resource-Saturation PCD exploits the resource contention (e.g., a fixed-size buffer) by sending carefully designed packets and monitoring different responses. Its effectiveness has been demonstrated on three commercial closed-source VoIP phones. The Stochastic PCD shows that timing side channels in the form of probing responses, which are caused by distinct resource-contention responses when different applications run in end nodes, enable effective PCD despite network and proxy-generated noise (e.g., jitter, delays). It was applied to WiFi and Instant Messaging for resource contention in the radio channel and the keyboard, respectively. Similar analysis enables practical Sybil node detection. Finally, the Service-Priority PCD utilizes the fact that 3G/2G mobile communication systems give higher priority to voice service than data service. This allows detection of the busy status of smartphones, and then discovery of their call records by correlating the busy status. This approach was successfully applied to iPhone and Android phones in AT&T's network. An additional, unanticipated finding was that an Internet user could disable a 2G phone's voice service by probing it with short enough intervals (e.g., 1 second). PCD defenses can be traditional side-channel countermeasures or PCD-specific ones, e.g., monitoring and blocking suspicious periodic network traffic

Understanding the Usage of Anonymous Onion Services: Empirical Experiments to Study Criminal Activities in the Tor Network

Technology is the new host of life, and with each passing year, developments in digitalization make it easier to destroy our understanding of authenticity. A man is more than his distorted shadow on Facebook wall. Another essential shadow dwells under anonymity.The aim of this thesis is to understand the usage of onion services in the Tor anonymity network. To be more precise the aim is to discover and measure human activities on Tor and on anonymous onion websites. We establish novel facts in the anonymous online environment. We solve technical problems, such as web-crawling and scraping to gather data. We represent new findings on how onion services hide illegal activities. The results are merged with wider range of anonymous onion services usage.We selected to cast light to the criminal dark side of the Tor network, mainly black marketplaces and hacking. This is a somewhat factitious selection from the wide range of Tor use. However, an archetype villain is found in nearly every story so naturally, for the sake of being interesting, we selected criminal phenomenon to study. To be clear, the Tor network is developed and utilised for legal online privacy and several other essential ways.The first finding is that as the Tor network becomes more popular also illegal activities become wide spread. Tor and virtual currencies are already transforming drug trade. Anonymous high-class marketplaces are difficult for the law enforcement to interrupt.On the other hand, now illegal activities are paradoxically more public than ever: everyone can access these onion sites and browse the product listings. The illegal trade is transparent to be followed. For example, by the means of web-crawling and scraping, we produced nearly real-time picture of the trade in Finland following one of the marketplaces on Tor. As a result, statistics shed light on substance consumption habits: the second study estimates that sales totalled over two million euros between Finnish buyers and sellers.Due to the network’s anonymity and nature of illegal sales, reputation systems have replaced the rule of law: a buyer trusts the seller’s reputation because the law is not guaranteeing the delivery. The only available information is the seller’s reputation and capacity which were both associated with drug sales as we prove.Finally, we will identify the limits of online anonymity ranging from technical limitations to operation security dangers. Technology is merely a communication channel and major criminal activities still happen in the physical world. For instance, a drug trade requires that the seller sends the products using post service to the buyer’s address. Before that the seller has acquired enormous amounts of illegal drugs. The buyer has to give away his address to the seller who could later be placed under arrest with a list of customers addresses. Furthermore, we show case by case how criminals reveal and leak their critical identity information. The law enforcement agencies are experienced to investigate all of these aspects even if the Tor network itself is secure

An adaptive approach to detecting behavioural covert channels in IPv6

One of the most important techniques in data hiding is (Metaferography) covert channel, which recently has shown potential impacts on network and data security. Encryption can only protect communication from being decoded, meanwhile, covert channel is the art of hiding information in an overt communication as a carrier of information. Covert channels are normally used for transferring information stealthily. They are used to leak information across the network and to ex/infiltrate classified information from legitimate targets. These hidden channels violate network security and privacy polices, it is easy to embed but unlikely and almost impossible to be detected. Despite of the obvious improvements in IPv6 components and functionality enhancements, there exist intrinsic security vulnerabilities. These vulnerabilities have ongoing implications on network security and traffic performance. Hence, they will create insecure environments in business and banking network, information security management and IT security. ICMPv6 is vital integral part in IPv6, as well as IPsec protocol, to mitigate and eliminate covert channels, the RFC standards and controls should be investigated intensively. Furthermore, incomplete implementation of IPv6 nowadays on all Operating Systems has not exposed the realm of this security protocol performance explicitly. In this thesis, we present a novel Hybrid Heuristic Intelligent Algorithm coupled with enhanced Polynomial Naïve Bayes machine Learning algorithm. The framework is implemented in a supervised learning model to detect and classify covert channels in IPv6. The proposed multi-threaded framework acts as an active security warden processing intelligent information gain and optimized decision trees technique to improve the security vulnerabilities in this new network generation protocol. This new approach develops intelligent heuristic techniques for in depth packet inspection to analyse and examine the header fields of IPv6 protocol. Some of these fields are designated by the designer for quality of service (QoS), future performance diagnostic analysis, unfortunately, they are misused by "bad guys and black hats" to perform various network security attacks against vulnerable targets. These attacks cause immediate and ongoing damage to classified data. In order to prevent and mitigate these types of breaches and threat risks, a multi-security prevention model was created. Furthermore, advanced machine learning technique was implemented to detect, classify and document all current and future unknown anomaly attacks. The suggested HeuBNet6 classiffier obtained highly significant results of 98% detection rate and showed better performance and accuracy with good True Positive Rate (TPR) and low False Positive Rate (FPR)

EFFICIENT RUNTIME SECURITY SYSTEM FOR DECENTRALISED DISTRIBUTED SYSTEMS

Distributed systems can be defined as systems that are scattered over geographical distances and provide different activities through communication, processing, data transfer and so on. Thus, increasing the cooperation, efficiency, and reliability to deal with users and data resources jointly. For this reason, distributed systems have been shown to be a promising infrastructure for most applications in the digital world. Despite their advantages, keeping these systems secure, is a complex task because of the unconventional nature of distributed systems which can produce many security problems like phishing, denial of services or eavesdropping. Therefore, adopting security and privacy policies in distributed systems will increase the trustworthiness between the users and these systems. However, adding or updating security is considered one of the most challenging concerns and this relies on various security vulnerabilities which existing in distributed systems. The most significant one is inserting or modifying a new security concern or even removing it according to the security status which may appear at runtime. Moreover, these problems will be exacerbated when the system adopts the multi-hop concept as a way to deal with transmitting and processing information. This can pose many significant security challenges especially if dealing with decentralized distributed systems and the security must be furnished as end-to-end. Unfortunately, existing solutions are insufficient to deal with these problems like CORBA which is considered a one-to-one relationship only, or DSAW which deals with end-to-end security but without taking into account the possibility of changing information sensitivity during runtime. This thesis provides a proposed mechanism for enforcing security policies and dealing with distributed systems’ security weakness in term of the software perspective. The proposed solution utilised Aspect-Oriented Programming (AOP), to address security concerns during compilation and running time. The proposed solution is based on a decentralized distributed system that adopts the multi-hop concept to deal with different requested tasks. The proposed system focused on how to achieve high accuracy, data integrity and high efficiency of the distributed system in real time. This is done through modularising the most efficient security solutions, Access Control and Cryptography, by using Aspect-Oriented Programming language. The experiments’ results show the proposed solution overcomes the shortage of the existing solutions by fully integrating with the decentralized distributed system to achieve dynamic, high cooperation, high performance and end-to-end holistic security

Context-aware access control in ubiquitous computing (CRAAC)

Ubiquitous computing (UbiComp) envisions a new computing environment, where computing devices and related technology are widespread (i.e. everywhere) and services are provided at anytime. The technology is embedded discreetly in the environment to raise users' awareness. UbiComp environments support the proliferation of heterogeneous devices such as embedded computing devices, personal digital assistants (PDAs), wearable computers, mobile phones, laptops, office desktops (PCs), and hardware sensors. These devices may be interconnected by common networks (e.g. wired, wireless), and may have different levels of capabilities (i.e. computational power, storage, power consumption, etc). They are seamlessly integrated and interoperated to provide smart services (i.e. adaptive services). A UbiComp environment provides smart services to users based on the users' and/or system's current contexts. It provides the services to users unobtrusively and in turn the user's interactions with the environment should be as non-intrusive and as transparent as possible. Access to such smart services and devices must be controlled by an effective access control system that adapts its decisions based on the changes in the surrounding contextual information. This thesis aims at designing an adaptive fine-grained access control solution that seamlessly fits into UbiComp environments. The solution should be flexible in supporting the use of different contextual information and efficient, in terms of access delays, in controlling access to resources with divergent levels of sensitivity. The main contribution of this thesis is the proposal of the Context-Risk-Aware Access Control (CRAAC) model. CRAAC achieves fine-grained access control based upon the risk level in the underlying access environment and/or the sensitivity level of the requested resource object. CRAAC makes new contributions to the access control field, those include 1) introducing the concept of level of assurance based access control, 2) providing a method to convert the contextual attributes values into the corresponding level of assurance, 3) Proposing two methods to aggregate the set of level of assurance into one requester level of assurance, 4) supporting four modes of working each suits a different application context and/or access control requirements, 5) a comprehensive access control architecture that supports the CRAAC four modes of working, and 6) an evaluation of the CRAAC performance at runtime.EThOS - Electronic Theses Online Serviceral Centre and Educational BureauCairo UniversityGBUnited Kingdo

Building Security Protocols Against Powerful Adversaries

As our sensitive data is increasingly carried over the Internet and stored remotely, security in communications becomes a fundamental requirement. Yet, today's security practices are designed around assumptions the validity of which is being challenged. In this thesis we design new security mechanisms for certain scenarios where traditional security assumptions do not hold. First, we design secret-agreement protocols for wireless networks, where the security of the secrets does not depend on assumptions about the computational limitations of adversaries. Our protocols leverage intrinsic characteristics of the wireless to enable nodes to agree on common pairwise secrets that are secure against computationally unconstrained adversaries. Through testbed and simulation experimentation, we show that it is feasible in practice to create thousands of secret bits per second. Second, we propose a traffic anonymization scheme for wireless networks. Our protocol aims in providing anonymity in a fashion similar to Tor - yet being resilient to computationally unbounded adversaries - by exploiting the security properties of our secret-agreement. Our analysis and simulation results indicate that our scheme can offer a level of anonymity comparable to the level of anonymity that Tor does. Third, we design a lightweight data encryption protocol for protecting against computationally powerful adversaries in wireless sensor networks. Our protocol aims in increasing the inherent weak security that network coding naturally offers, at a low extra overhead. Our extensive simulation results demonstrate the additional security benefits of our approach. Finally, we present a steganographic mechanism for secret message exchange over untrustworthy messaging service providers. Our scheme masks secret messages into innocuous texts, aiming in hiding the fact that secret message exchange is taking place. Our results indicate that our schemes succeeds in communicating hidden information at non-negligible rates