Usage control in SIP-based multimedia delivery

The Session Initiation Protocol (SIP) is an application layer signaling protocol for the creation, modification and termination of multimedia sessions and VoIP calls with one or more participants.SIP is widely accepted as the protocol that will dominate multimedia communications in the future and one of the reasons is that it can inherently support multidomain heterogeneous networks.While SIP operates in highly dynamic environments, in the current version its authorization support is based on traditional access control models.The main problem these models face is that they were designed many years ago, and under some circumstances tend to be inadequate in modern highly dynamic environments.Usage Control (UCON), instead, is a model that supports the same operations as traditional access control models do, but it further enhances them with novel ones.In previous work, an architecture supporting continuous authorizations on SIP, based on the UCON model, was presented.In this paper, an authorization support implementing the whole UCON model, including authorizations, obligations and conditions, has been integrated in a SIP system.Moreover, a testbed has been set up to experimentally evaluate the performance of the proposed security mechanism

Keep your memory dump shut: Unveiling data leaks in password managers

Password management has long been a persistently challenging task. This led to the introduction of password management software, which has been around for at least 25 years in various forms, including desktop and browser-based applications. This work assesses the ability of two dozen password managers, 12 desktop applications, and 12 browser-plugins, to effectively protect the confidentiality of secret credentials in six representative scenarios. Our analysis focuses on the period during which a Password Manager (PM) resides in the RAM. Despite the sensitive nature of these applications, our results show that across all scenarios, only three desktop PM applications and two browser plugins do not store plaintext passwords in the system memory. Oddly enough, at the time of writing, only two vendors recognized the exploit as a vulnerability, reserving CVE-2023-23349, while the rest chose to disregard or underrate the issue

Evaluation of Cryptography Usage in Android Applications

Mobile application developers are using cryptography in their products to protect sensitive data like passwords, short messages, documents etc. In this paper, we study whether cryptography and related techniques are employed in a proper way, in order to protect these private data. To this end, we downloaded 49 Android applications from the Google Play marketplace and performed static and dynamic analysis in an attempt to detect possible cryptographic misuses. The results showed that 87.8 % of the applications present some kind of misuse, while for the rest of them no cryptography usage was detected during the analysis. Finally, we suggest countermeasures, mainly intended for developers, to alleviate the issues identified by the analysis

Demystifying COVID-19 digital contact tracing: A survey on frameworks and mobile apps

The coronavirus pandemic is a new reality and it severely affects the modus vivendi of the international community. In this context, governments are rushing to devise or embrace novel surveillance mechanisms and monitoring systems to fight the outbreak. The development of digital tracing apps, which among others are aimed at automatising and globalising the prompt alerting of individuals at risk in a privacy-preserving manner is a prominent example of this ongoing effort. Very promptly, a number of digital contact tracing architectures has been sprouted, followed by relevant app implementations adopted by governments worldwide. Bluetooth, and specifically its Low Energy (BLE) power-conserving variant has emerged as the most promising short-range wireless network technology to implement the contact tracing service. This work offers the first to our knowledge, full-fledged review of the most concrete contact tracing architectures proposed so far in a global scale. This endeavour does not only embrace the diverse types of architectures and systems, namely centralised, decentralised, or hybrid, but it equally addresses the client side, i.e., the apps that have been already deployed in Europe by each country. There is also a full-spectrum adversary model section, which does not only amalgamate the previous work in the topic, but also brings new insights and angles to contemplate upon.Comment: 34 pages, 3 figure

A Survey on Digital Certificates Approaches for the COVID-19 Pandemic

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Blockchain in Energy Communities, A proof of concept

This report aims at exploring the use of the distributed ledger paradigm to incentive the participation of the citizen to a truly free, open and interoperable energy market, producing a feasibility study and a first demo testbed, taking also into consideration privacy, cybersecurity and big-data issues of the smart-home in the Energy market context. This study is intended to support point 4.1, 4.2 and 4.3 of the DSM (COM(2015)192) and point 2.2 of the Energy Union package (COM(2015)80.JRC.E.3-Cyber and Digital Citizens' Securit

Neither Denied nor Exposed: Fixing WebRTC Privacy Leaks

To establish peer-to-peer connections and achieve realtime web-based communication, the WebRTC framework requires address information of the communicating peers. This means that users behind, say, NAT or firewalls normally rely on the ICE framework for the sake of negotiating information about the connection and media transferring. This typically involves STUN/TURN servers, which assist the peers discover each other's IP:port from a public perspective, and relay traffic if direct connection fails. Nevertheless, this IP:port private information can be easily captured by anyone who owns the corresponding STUN/TURN server. While this is acceptable for a user that deliberately initiates a WebRTC connection, it becomes a worrisome privacy issue for those being unaware that such a connection is attempted. Even though this problem is known in the related literature, no practical solution has been proposed so far. To this end, and for the sake of detecting and preventing in realtime the execution of STUN/TURN clandestine, privacy-invading requests, we introduce two different kinds of solutions (a) a browser extension, and (b) an HTTP gateway, implemented in both C++ and Golang. Both solutions detect any WebRTC API call before it happens and inform accordingly the end-user about the webpage's intentions. We meticulously evaluate the proposed schemes in terms of performance and demonstrate that even in the worst case, the latency introduced is tolerable.JRC.E.3-Cyber and Digital Citizens' Securit

OnionSIP: Preserving Privacy in SIP with Onion Routing

While more and more users turn to IP-based communication technologies, privacy and anonymity remain largely open issues. One of the most prominent VoIP protocols for multimedia session management is SIP which, despite its popularity, suffers from security and privacy aws. As SIP messages are sent in plain text, user data are exposed to intermediate proxies and eavesdroppers. As a result, information about users participating in a call can leak from header data, which cannot be omitted since they are needed for the correct routing of SIP messages to their final destination. Even more, traffic analysis attacks can be mounted with data stemming from lower layers. To redress this kind of problems, privacy can be achieved either by the construction of a lower level tunnel (via the use of SSL or IPsec protocols) or by employing a customtailored solution. However, SSL and IPsec are known for leading to undesirable, non affordable delays, and thus the need for a SIP-oriented solution is preferable. In the context of this article, we evaluate three alternative solutions to encounter the above issues. More specifically, we use two well-known anonymity networks, Tor and I2P, for secluding both caller's and callee's actions by securing SIP messages content. As a third solution, we present our proposal for preserving privacy in SIP signaling, by using an onion-routing approach, where selected sensitive fields of SIP messages are encrypted using either asymmetric or symmetric encryption. We compare these three alternatives in terms of performance, mentioning the pros and cons that come up with each proposal. Our work also presents the reasons why other existing anonymity networks fail to be considered as appropriate for preserving anonymity in SIP

Complete SIP message obfuscation: PrivaSIP over Tor

Anonymity on SIP signaling can be achieved either by the construction of a lower level tunnel (via the use of SSL or IPSec protocols) or by employing a custom-tailored solution. Unfortunately, the former category of solutions present significant impediments including the requirement for a PKI and the hop-by-hop fashioned protection, while the latter only concentrate on the application layer, thus neglecting sensitive information leaking from lower layers. To remediate this problem, in the context of this paper, we employ the well-known Tor anonymity systemto achieve complete SIP traffic obfuscation from an attacker's standpoint. Specifically, we capitalize on Tor for preserving anonymity on network links that are considered mostly untrusted, i.e., those among SIP proxies and the one between the last proxy in the chain and the callee. We also, combine this Tor-powered solution with PrivaSIP to achieve an even greater level of protection. By employing PrivaSIP we assure that: (a) the first hop in the path (i.e., between the caller and the outbound proxy) affords anonymity, (b) the callee does not know the real identity of the caller, and (c) no real identities of both the caller and the callee are stored in log files. We also evaluate this scheme in terms of performance and show that even in the worst case, the latency introduced is not so high as it might be expected due to the use of Tor.JRC.E.2-Technology Innovation in Securit