Traffic Analysis Attacks on Skype VoIP Calls

Skype is one of the most popular voice-over-IP (VoIP) service providers. One of the main reasons for the popularity of Skype VoIP services is its unique set of features to protect privacy of VoIP calls such as strong encryption, proprietary protocols, unknown codecs, dynamic path selection, and the constant packet rate. In this paper, we propose a class of passive traffic analysis attacks to compromise privacy of Skype VoIP calls. The proposed attacks are based on application-level features extracted from VoIP call traces. The proposed attacks are evaluated by extensive experiments over different types of networks including commercialized anonymity networks and our campus network. The experiment results show that the proposed traffic analysis attacks can greatly compromise the privacy of Skype calls. Possible countermeasure to mitigate the proposed traffic analysis attacks are analyzed in this paper

Traffic Analysis Attacks on Skype VoIP Calls

Skype is one of the most popular voice-over-IP (VoIP) service providers. One of the main reasons for the popularity of Skype VoIP services is its unique set of features to protect privacy of VoIP calls such as strong encryption, proprietary protocols, unknown codecs, dynamic path selection, and the constant packet rate. In this paper, we propose a class of passive traffic analysis attacks to compromise privacy of Skype VoIP calls. The proposed attacks are based on application-level features extracted from VoIP call traces. The proposed attacks are evaluated by extensive experiments over different types of networks including commercialized anonymity networks and our campus network. The experiment results show that the proposed traffic analysis attacks can greatly compromise the privacy of Skype calls. Possible countermeasure to mitigate the proposed traffic analysis attacks are analyzed in this paper

On Traffic Analysis Attacks to Encrypted VOIP Calls

The increasing popularity of VoIP telephony has brought a lot of attention and concern over security and privacy issues of VoIP communication. This thesis proposes a new class of traffic analysis attacks to encrypted VoIP calls. The goal of these attacks is to detect speaker or speech of encrypted VoIP calls. The proposed traffic analysis attacks exploit silent suppression, an essential feature of VoIP telephony. These attacks are based on application-level features so that the attacks can detect the same speech or the same speaker of different VoIP calls made with different VoIP codecs. We evaluate the proposed attacks by extensive experiments over different type of networks including commercialized anonymity networks and campus networks. The experiments show that the proposed traffic analysis attacks can detect speaker and speech of encrypted VoIP calls with a high detection rate which is a great improvement comparing with random guess. With the help of intersection attacks, the detection rate for speaker detection can be increased. In order to shield the detrimental effect of this proposed attacks, a countermeasure is proposed to mitigate the proposed traffic analysis attack

On Traffic Analysis Attacks to Encrypted VOIP Calls

The increasing popularity of VoIP telephony has brought a lot of attention and concern over security and privacy issues of VoIP communication. This thesis proposes a new class of traffic analysis attacks to encrypted VoIP calls. The goal of these attacks is to detect speaker or speech of encrypted VoIP calls. The proposed traffic analysis attacks exploit silent suppression, an essential feature of VoIP telephony. These attacks are based on application-level features so that the attacks can detect the same speech or the same speaker of different VoIP calls made with different VoIP codecs. We evaluate the proposed attacks by extensive experiments over different type of networks including commercialized anonymity networks and campus networks. The experiments show that the proposed traffic analysis attacks can detect speaker and speech of encrypted VoIP calls with a high detection rate which is a great improvement comparing with random guess. With the help of intersection attacks, the detection rate for speaker detection can be increased. In order to shield the detrimental effect of this proposed attacks, a countermeasure is proposed to mitigate the proposed traffic analysis attack

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

Taxonomy of P2P Applications

Peer-to-peer (p2p) networks have gained immense popularity in recent years and the number of services they provide continuously rises. Where p2p-networks were formerly known as file-sharing networks, p2p is now also used for services like VoIP and IPTV. With so many different p2p applications and services the need for a taxonomy framework rises. This paper describes the available p2p applications grouped by the services they provide. A taxonomy framework is proposed to classify old and recent p2p applications based on their characteristics

Securing VoIP: A Framework to Mitigate or Manage Risks

In Australia, the past few years have seen Voice over IP (VoIP) move from a niche communications medium used by organisations with the appropriate infrastructure and capabilities to a technology that is available to any one with a good broadband connection. Driven by low cost and no cost phone calls, easy to use VoIP clients and increasingly reliable connections, VoIP is replacing the Public Switch Telephone Network (PSTN) in a growing number of households. VoIP adoption appears to be following a similar path to early Internet adoption, namely little awareness by users of the security implications. Lack of concern about security by VoIP users is probably due to the relatively risk free service provided by the PSTN. However, VoIP applications use the Internet as their communications medium and therefore the risk profile is significantly different to the PSTN. This paper reviews the risks for two VoIP implementation models now being increasingly used in Australian homes; the PC softphone and the Analogue Telephony Adaptor (ATA). An overview of each of the VoIP implementation models is given together with a description of the respective technologies and protocols utilised. The VoIP security threats, applicable to the two VoIP implementation models considered, are enumerated and vulnerabilities that could be exploited are considered. Available security mechanisms that address the identified vulnerabilities are discussed. A practical and pragmatic VoIP security framework is proposed that will enable a user to mitigate or manage the risks associated with using the VoIP implementation models considered. By applying the VoIP security framework a user will be able to deploy a secure VoIP solution appropriate for residential use

Evaluation of users’ perspective on VOIP’s security vulnerabilities

Voice over Internet protocol (VoIP) represents a major newish trend in telecommunications and an alternative to traditional phone systems. VoIP uses IP networks and therefore inherits their vulnerabilities. Adding voice traffic to IP networks complicates security issues and introduces a range of vulnerabilities. A VoIP system may face either an exclusive attack or an attack to the underlying IP network. The significance of security and privacy in VoIP communications are well known, and many studies mostly from the technical perspective have been published. However to date, no known research has been conducted to evaluate users’ perspectives on these issues. In light of this scarcity, we carried out a survey to evaluate users’ awareness of VoIP security vulnerabilities, and their attitudes towards privacy in VoIP communications. An overall finding highlights the fact that the majority of participants are neither concerned about VoIP privacy (eavesdropping) or VoIP security