Anonymous IP-Address Blocking in Tor with Trusted Computing (Work in Progress)
How does one block an anonymous user hiding behind an anonymous routing network? In this paper, we outline a security protocol that uses resource-constrained trusted hardware to facilitate anonymous IP-address blocking in anonymizing networks such as Tor. Tor allows users to access Internet services privately by using a series of Tor routers to obfuscate the route from the client to the server, thereby hiding the client’s IP address from the server. The success of Tor, however, has been limited because of malicious users who misuse the network. For example, anonymous users can deface websites or create malicious entries on websites such as Wikipedia. Administrators of these websites routinely rely on IP-address blocking for disabling misbehaving users’ accesses. The IP-address anonymity provided by Tor, however, makes it difficult for administrators to deny access to such offenders. As a result, administrators resort to blocking all Tor exit nodes, effectively denying anonymous access for all Tor’s users. Our solution makes use of trusted hardware and allows services like Tor to provide anonymous blocking of IP addresses while requiring only a modest amount of storage at the trusted node.
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.
- The following copyright notice applies to all of the above items that appear in IEEE publications: "Personal use of this material is permitted. However, permission to reprint/publish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from IEEE."
- The following copyright notice applies to all of the above items that appear in ACM publications: "© ACM, effective the year of publication shown in the bibliographic information. This file is the author’s version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in the journal or proceedings indicated in the bibliographic data for each item."
- The following copyright notice applies to all of the above items that appear in IFAC publications: "Document is being reproduced under permission of the Copyright Holder. Use or reproduction of the Document is for informational or personal use only."
