A novel mechanism for anonymizing Global System for Mobile Communications calls using a resource-based Session Initiation Protocol community network

Considering the widespread adoption of smartphones in mobile communications and the well-established resource sharing use in the networking community, we present a novel mechanism to achieve anonymity in the Global System for Mobile Communications (GSM). We propose a Voice over Internet Protocol infrastructure using the Session Initiation Protocol (SIP) where a smartphone registers on a SIP registrar and can start GSM conversation through another smartphone acting as a GSM gateway, by using a SIP intermediate without an extra cost. The testbed that we developed for empirical evaluation revealed no significant quality of service degradation

A Comprehensive Survey of Voice over IP Security Research

We present a comprehensive survey of Voice over IP security academic research, using a set of 245 publications forming a closed cross-citation set. We classify these papers according to an extended version of the VoIP Security Alliance (VoIPSA) Threat Taxonomy. Our goal is to provide a roadmap for researchers seeking to understand existing capabilities and to identify gaps in addressing the numerous threats and vulnerabilities present in VoIP systems. We discuss the implications of our findings with respect to vulnerabilities reported in a variety of VoIP products. We identify two specific problem areas (denial of service, and service abuse) as requiring significant more attention from the research community. We also find that the overwhelming majority of the surveyed work takes a black box view of VoIP systems that avoids examining their internal structure and implementation. Such an approach may miss the mark in terms of addressing the main sources of vulnerabilities, i.e., implementation bugs and misconfigurations. Finally, we argue for further work on understanding cross-protocol and cross-mechanism vulnerabilities (emergent properties), which are the byproduct of a highly complex system-of-systems and an indication of the issues in future large-scale systems

Public key certificate privacy in VoNDN: voice over named data networks

Scenarios were scripted by the C++11 library in ndnSIM 2.6. The scenario implementations and required tools can be publicly accessible at the author’s GitHub account—https://git.io/JJqEwNamed Data Network (NDN) is a network paradigm that attempts to answer today's needs for distribution. One of the NDN key features is in-network caching to increase content distribution and network efficiency. However, this feature may increase the privacy concerns, as the adversary may identify the call history, and the callee/caller location through side-channel timing responses from the cache of trusted Voice over NDN (VoNDN) application routers. The side-channel timing attack can be mitigated by countermeasures, such as additional unpredictable delay, random caching, group signatures, and no-caching configurations. However, the content distribution may be affected by pre-configured countermeasures, which may be against the original purpose of NDN. In this work, the detection and defense (DaD) approach is proposed to mitigate the attack efficiently and effectively. With the DaD usage, an attack can be detected by a multi-level detection mechanism, in order to apply the countermeasures against the adversarial faces. Also, the detections can be used to determine the severity of the attack. In order to detect the behavior of an adversary, a brute-force timing attack was implemented and simulated of the VoNDN application on NDN-testbed. A trusted application that mimics the VoNDN and identifies the cached certificate on a worldwide NDN-testbed. In simulation primary results showed that the multi-level detection based on DaD mitigated the attack about 39.1% in best-route, and 36.5% in multicast communications. Additionally, the results showed that DaD preserves privacy without compromising the efficiency benefits of in-network caching in the VoNDN application.This work was supported by the Fundacao para a Ciencia e Tecnologia (FCT) within the Research and Development Units Project Scope under Grant UIDB/00319/2020

Shadow Phone and Ghost SIM: A Step Toward Geolocation Anonymous Calling

abstract: Mobile telephony is a critical aspect of our modern society: through telephone calls, it is possible to reach almost anyone around the globe. However, every mobile telephone call placed implicitly leaks the user's location to the telephony service provider (TSP). This privacy leakage is due to the fundamental nature of mobile telephony calls that must connect to a local base station to receive service and place calls. Thus, the TSP can track the physical location of the user for every call that they place. While the The Internet is similar in this regard, privacy-preserving technologies such as Tor allow users to connect to websites anonymously (without revealing to their ISP the site that they are visiting). In this thesis, the scheme presented, called shadow calling, to allow geolocation anonymous calling from legacy mobile devices. In this way, the call is placed from the same number, however, the TSP will not know the user's physical location. The scheme does not require any change on the network side and can be used on current mobile networks. The scheme implemented is for the GSM (commonly referred to as 2G) network, as it is the most widely used mode of mobile telephony communication. The feasibility of our scheme is demonstrated through the prototype. Shadow calling, which renders the users geolocation anonymous, will be beneficial for users such as journalists, human rights activists in hostile nations, or other privacy-demanding users.Dissertation/ThesisMasters Thesis Computer Science 201

A method for forensic artifact collection, analysis and incident response in environments running Session Initiation Protocol (SIP) and Session Description protocol

In this paper, we perform an analysis of SIP, a popular voice over IP (VoIP) protocol and propose a framework for capturing and analysing volatile VoIP data in order to determine forensic readiness requirements for effectively identifying an attacker. The analysis was performed on real attack data and the findings were encouraging. It seems that if appropriate forensic readiness processes and controls are in place, a wealth of evidence can be obtained. The type of the end user equipment of the internal users, the private IP, the software that is used can help build a reliable baseline information database. On the other hand the private IP addresses of the potential attacker even during the presence of NAT services, as well as and the attack tools employed by the malicious parties are logged for further analysis

Authentic-caller : self-enforcing authentication in a next generation network

The Internet of Things (IoT) or the Cyber-Physical System (CPS) is the network of connected devices, things and people which collect and exchange information using the emerging telecommunication networks (4G, 5G IP-based LTE). These emerging telecommunication networks can also be used to transfer critical information between the source and destination, informing the control system about the outage in the electrical grid, or providing information about the emergency at the national express highway. This sensitive information requires authorization and authentication of source and destination involved in the communication. To protect the network from unauthorized access and to provide authentication, the telecommunication operators have to adopt the mechanism for seamless verification and authorization of parties involved in the communication. Currently, the next-generation telecommunication networks use a digest-based authentication mechanism, where the call-processing engine of the telecommunication operator initiates the challenge to the request-initiating client or caller, which is being solved by the client to prove his credentials. However, the digest-based authentication mechanisms are vulnerable to many forms of known attacks e.g., the Man-In-The-Middle (MITM) attack and the password guessing attack. Furthermore, the digest-based systems require extensive processing overheads. Several Public-Key Infrastructure (PKI) based and identity-based schemes have been proposed for the authentication and key agreements. However, these schemes generally require smart-card to hold long-term private keys and authentication credentials. In this paper, we propose a novel self-enforcing authentication protocol for the SIPbased next-generation network based on a low-entropy shared password without relying on any PKI or trusted third party system. The proposed system shows effective resistance against various attacks e.g., MITM, replay attack, password guessing attack, etc. We a..

I Know Where You are and What You are Sharing: Exploiting P2P Communications to Invade Users' Privacy

In this paper, we show how to exploit real-time communication applications to determine the IP address of a targeted user. We focus our study on Skype, although other real-time communication applications may have similar privacy issues. We first design a scheme that calls an identified targeted user inconspicuously to find his IP address, which can be done even if he is behind a NAT. By calling the user periodically, we can then observe the mobility of the user. We show how to scale the scheme to observe the mobility patterns of tens of thousands of users. We also consider the linkability threat, in which the identified user is linked to his Internet usage. We illustrate this threat by combining Skype and BitTorrent to show that it is possible to determine the file-sharing usage of identified users. We devise a scheme based on the identification field of the IP datagrams to verify with high accuracy whether the identified user is participating in specific torrents. We conclude that any Internet user can leverage Skype, and potentially other real-time communication systems, to observe the mobility and file-sharing usage of tens of millions of identified users.Comment: This is the authors' version of the ACM/USENIX Internet Measurement Conference (IMC) 2011 pape