Post on 03-Jun-2018
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ABSTRACT
Anonymizing networks such as Tor allow users to access Internet services
privately by using a series of routers to hide the clients IP address from the server.
The success of such networks, however, has been limited by users employing this
anonymity for abusive purposes such as defacing popular websites. ebsite
administrators routinely rely on IP!address blocking for disabling access to
misbehaving users, but blocking IP addresses is not practical if the abuser routes
through an anonymizing network. As a result, administrators block all known e"it
nodes of anonymizing networks, denying anonymous access to misbehaving and
behaving users alike. To address this problem, we present #ymble, a system in which
servers can $blacklist% misbehaving users, thereby blocking users without
compromising their anonymity. &ur system is thus agnostic to different servers
definitions of misbehavior ' servers can blacklist users for whatever reason, and the
privacy of blacklisted users is maintained.
PROJECT PURPOSE
Anonymizing networks such as Tor allow users to access Internet servicesprivately by using a series of routers to hide the clients IP address from the server.
The success of such networks, however, has been limited by users employing this
anonymity for abusive purposes such as defacing popular eb sites. eb site
administrators routinely rely on IP!address blocking for disabling access to
misbehaving users, but blocking IP addresses is not practical if the abuser routes
through an anonymizing network.
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PROJECT SCOPE
eb site administrators cannot blacklist individual malicious users IP
addresses, they
blacklist the entire anonymizing network. (uch measures eliminate malicious activity
through anonymizing networks at the cost of denying anonymous access to behaving
users. In #ymble, users ac)uire an ordered collection of nymbles, a special type of
pseudonym, to connect toebsites. ithout additional information, these nymbles are
computationally hard to link,* and hence, using the stream of nymbles simulates
anonymous access to services.
eb sites, however, can blacklist users by obtaining a seed for a particular nymble,
allowing them to link future nymbles from the same user'those used before the
complaint remain unlinkable. (ervers can therefore blacklist anonymous users without
knowledge of their IP addresses while allowing behaving users to connect
anonymously.
PRODUCT FEATURES
e have proposed and built a comprehensive credential system called #ymble,
which can be used to add a layer of accountability to any publicly known anonymizing
network. (ervers can blacklist misbehaving users while maintaining their privacy, and
we show how these properties can be attained in a way that is practical, efficient, and
sensitive to the needs of both users and services.
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LIST OF THE TABLE
SERIAL NO TABLE NO TABLE NAME PAGE NO
1 3.3.1 ADDRESS 26
2 3.3.2 LOGIN 26
3 3.3.3 RESOURCE 26
4 3.3.4 SERVER 26
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LIST OF FIGURES
SERIAL NO FIGURE NO FIGURE NAME PAGE NO1 2.2.1 overve! o" #$e
%&%#e'
6
2 2.2.3 (r)$#e)#*re o" #$e
%&%#e' +e%,-
3 3.1.1 D"+ /eve/ 0 20
4 3.1.2 D"+ /eve/ 1 22
3.2.4 C"+ 2
6 .1 N&'/e %erver 6
.2 N&'/e %erver
(*#$e-#)(#o-
6
.3 N&'/e $o'e
(,e
65
5 .4 N'/e ve! 0
10 . U%er ve! 1
11 .6 A++-, (++re%% 2
12 . B/o)-,
(++re%%
3
13 . P%e*+o '(-(,er 4
14 .5 F/e ())e%%
LIST OF ABBREVIATION
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+fd +ata flow diagram
-fd -ontrol flow diagram
Tor The onion router
/0 erifier!local revocation&+1- 2icrosoft &pen +atabase -onnectivity
3+1- 3ava +atabase -onnectivity
v