222,545 research outputs found
Spying the World from your Laptop -- Identifying and Profiling Content Providers and Big Downloaders in BitTorrent
This paper presents a set of exploits an adversary can use to continuously
spy on most BitTorrent users of the Internet from a single machine and for a
long period of time. Using these exploits for a period of 103 days, we
collected 148 million IPs downloading 2 billion copies of contents. We identify
the IP address of the content providers for 70% of the BitTorrent contents we
spied on. We show that a few content providers inject most contents into
BitTorrent and that those content providers are located in foreign data
centers. We also show that an adversary can compromise the privacy of any peer
in BitTorrent and identify the big downloaders that we define as the peers who
subscribe to a large number of contents. This infringement on users' privacy
poses a significant impediment to the legal adoption of BitTorrent
Compromising Tor Anonymity Exploiting P2P Information Leakage
Privacy of users in P2P networks goes far beyond their current usage and is a
fundamental requirement to the adoption of P2P protocols for legal usage. In a
climate of cold war between these users and anti-piracy groups, more and more
users are moving to anonymizing networks in an attempt to hide their identity.
However, when not designed to protect users information, a P2P protocol would
leak information that may compromise the identity of its users. In this paper,
we first present three attacks targeting BitTorrent users on top of Tor that
reveal their real IP addresses. In a second step, we analyze the Tor usage by
BitTorrent users and compare it to its usage outside of Tor. Finally, we depict
the risks induced by this de-anonymization and show that users' privacy
violation goes beyond BitTorrent traffic and contaminates other protocols such
as HTTP
Spoiled Onions: Exposing Malicious Tor Exit Relays
Several hundred Tor exit relays together push more than 1 GiB/s of network
traffic. However, it is easy for exit relays to snoop and tamper with
anonymised network traffic and as all relays are run by independent volunteers,
not all of them are innocuous.
In this paper, we seek to expose malicious exit relays and document their
actions. First, we monitored the Tor network after developing a fast and
modular exit relay scanner. We implemented several scanning modules for
detecting common attacks and used them to probe all exit relays over a period
of four months. We discovered numerous malicious exit relays engaging in
different attacks. To reduce the attack surface users are exposed to, we
further discuss the design and implementation of a browser extension patch
which fetches and compares suspicious X.509 certificates over independent Tor
circuits.
Our work makes it possible to continuously monitor Tor exit relays. We are
able to detect and thwart many man-in-the-middle attacks which makes the
network safer for its users. All our code is available under a free license
Defending Tor from Network Adversaries: A Case Study of Network Path Prediction
The Tor anonymity network has been shown vulnerable to traffic analysis
attacks by autonomous systems and Internet exchanges, which can observe
different overlay hops belonging to the same circuit. We aim to determine
whether network path prediction techniques provide an accurate picture of the
threat from such adversaries, and whether they can be used to avoid this
threat. We perform a measurement study by running traceroutes from Tor relays
to destinations around the Internet. We use the data to evaluate the accuracy
of the autonomous systems and Internet exchanges that are predicted to appear
on the path using state-of-the-art path inference techniques; we also consider
the impact that prediction errors have on Tor security, and whether it is
possible to produce a useful overestimate that does not miss important threats.
Finally, we evaluate the possibility of using these predictions to actively
avoid AS and IX adversaries and the challenges this creates for the design of
Tor
Portable Tor Router: Easily Enabling Web Privacy for Consumers
On-line privacy is of major public concern. Unfortunately, for the average
consumer, there is no simple mechanism to browse the Internet privately on
multiple devices. Most available Internet privacy mechanisms are either
expensive, not readily available, untrusted, or simply provide trivial
information masking. We propose that the simplest, most effective and
inexpensive way of gaining privacy, without sacrificing unnecessary amounts of
functionality and speed, is to mask the user's IP address while also encrypting
all data. We hypothesized that the Tor protocol is aptly suited to address
these needs. With this in mind we implemented a Tor router using a single board
computer and the open-source Tor protocol code. We found that our proposed
solution was able to meet five of our six goals soon after its implementation:
cost effectiveness, immediacy of privacy, simplicity of use, ease of execution,
and unimpaired functionality. Our final criterion of speed was sacrificed for
greater privacy but it did not fall so low as to impair day-to-day
functionality. With a total cost of roughly $100.00 USD and a speed cap of
around 2 Megabits per second we were able to meet our goal of an affordable,
convenient, and usable solution to increased on-line privacy for the average
consumer.Comment: 6 pages, 5 figures, IEEE ICCE Conferenc
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