Arvind Narayanan - Profile on Academia.edu (original) (raw)

Papers by Arvind Narayanan

Abstract: While the Internet was conceived as a decentralized network, the most widely used web a... more Abstract: While the Internet was conceived as a decentralized network, the most widely used web applications today tend toward centralization. Control increasingly rests with centralized service providers who, as a consequence, have also amassed unprecedented amounts of data about the behaviors and personalities of individuals.

The ease of large-scale data collection. Before the growth of the Internet, collection of data fr... more The ease of large-scale data collection. Before the growth of the Internet, collection of data from individuals on a national or global scale was feasible only for governments and very large corporations. The infrastructure required for collecting and aggregating data was either in the form of a door-to-door survey as in a census, or a pervasive physical presence, such as a large supermarket chain collecting data on people's shopping habits.

Secret sharing is a very important primitive in cryptography and distributed computing. In this w... more Secret sharing is a very important primitive in cryptography and distributed computing. In this work, we consider computational secret sharing (CSS) which provably allows a smaller share size (and hence greater efficiency) than its information-theoretic counterparts. Extant CSS schemes result in succinct share-size and are in a few cases, like threshold access structures, optimal.

Abstract We study the problem of circuit obfuscation, ie, transforming the circuit in a way that ... more Abstract We study the problem of circuit obfuscation, ie, transforming the circuit in a way that hides everything except its input-output behavior. Barak et al. showed that a universal obfuscator that obfuscates every circuit class cannot exist, leaving open the possibility of special-purpose obfuscators.

Abstract We study techniques for identifying an anonymous author via linguistic stylometry, ie, c... more Abstract We study techniques for identifying an anonymous author via linguistic stylometry, ie, comparing the writing style against a corpus of texts of known authorship. We experimentally demonstrate the effectiveness of our techniques with as many as 100,000 candidate authors. Given the increasing availability of writing samples online, our result has serious implications for anonymity and free speech-an anonymous blogger or whistleblower may be unmasked unless they take steps to obfuscate their writing style.

We consider the problem of reliable message transmission between two synchronous players connecte... more We consider the problem of reliable message transmission between two synchronous players connected by n wires, some t < n/2 of which may be faulty. We show how to get reliability "for free"-reliable transmission of b bits involves a total communication of only O(b) bits, when b is large enough. We also construct an efficient Perfectly Secure Message Transmission Protocol.

We propose an efficient and robust Pay TV scheme for the case when there are a number of streams,... more We propose an efficient and robust Pay TV scheme for the case when there are a number of streams, as opposed to just one. In our model, the broadcast is divided into billing periods; during each billing period the entitlement of the users does not change. We achieve full flexibility with only a constant factor data redundancy. Our scheme has very little secure memory requirements and does not require the users' secure keys to be changed once they have been written into the secure memory.

Abstract We study privacy-preserving tests for proximity: Alice can test if she is close to Bob w... more Abstract We study privacy-preserving tests for proximity: Alice can test if she is close to Bob without either party revealing any other information about their location. We describe several secure protocols that support private proximity testing at various levels of granularity. We study the use of “location tags” generated from the physical environment in order to strengthen the security of proximity testing. We implemented our system on the Android platform and report on its effectiveness.

In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players ... more In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players (or processors), the Sender S and the Receiver R are connected by n wires (each of which facilitates 2-way communication); S has an ℓ-bit message that he wishes to send to R; after exchanging messages in phasesA phase is a send from S to R or from R\ bf R to S\ bf S or both simultaneously.

… and Privacy (SP), …, Jan 1, 2011

Many commercial websites use recommender systems to help customers locate products and content. M... more Many commercial websites use recommender systems to help customers locate products and content. Modern recommenders are based on collaborative filtering: they use patterns learned from users' behavior to make recommendations, usually in the form of related-items lists. The scale and complexity of these systems, along with the fact that their outputs reveal only relationships between items (as opposed to information about users), may suggest that they pose no meaningful privacy risk.

Communications of the ACM, Jan 1, 2010

Arxiv preprint arXiv:1102.4374, Jan 1, 2011

This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.c... more This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.com. The goal of the contest was to promote research on realworld link prediction, and the dataset was a graph obtained by crawling the popular Flickr social photo sharing website, with user identities scrubbed. By de-anonymizing much of the competition test set using our own Flickr crawl, we were able to effectively game the competition. Our attack represents a new application of de-anonymization to gaming machine learning contests, suggesting changes in how future competitions should be run.

Communications of the ACM, Jan 1, 2010

… of the 12th ACM conference on …, Jan 1, 2005

We investigate whether it is possible to encrypt a database and then give it away in such a form ... more We investigate whether it is possible to encrypt a database and then give it away in such a form that users can still access it, but only in a restricted way. In contrast to conventional privacy mechanisms that aim to prevent any access to individual records, we aim to restrict the set of queries that can be feasibly evaluated on the encrypted database.

17th Annual Network & …, Jan 1, 2010

Online behavioral advertising (OBA) refers to the practice of tracking users across web sites in ... more Online behavioral advertising (OBA) refers to the practice of tracking users across web sites in order to infer user interests and preferences. These interests and preferences are then used for selecting ads to present to the user. There is great concern that behavioral advertising in its present form infringes on user privacy. The resulting public debate -which includes consumer advocacy organizations, professional associations, and government agencies -is premised on the notion that OBA and privacy are inherently in conflict.

… of the 12th ACM conference on …, Jan 1, 2005

Human-memorable passwords are a mainstay of computer security. To decrease vulnerability of passw... more Human-memorable passwords are a mainstay of computer security. To decrease vulnerability of passwords to bruteforce dictionary attacks, many organizations enforce complicated password-creation rules and require that passwords include numerals and special characters. We demonstrate that as long as passwords remain human-memorable, they are vulnerable to "smart-dictionary" attacks even when the space of potential passwords is large.

… 30th IEEE Symposium on Security and …, Jan 1, 2009

Operators of online social networks are increasingly sharing potentially sensitive information ab... more Operators of online social networks are increasingly sharing potentially sensitive information about users and their relationships with advertisers, application developers, and data-mining researchers. Privacy is typically protected by anonymization, i.e., removing names, addresses, etc.

2008 IEEE Symposium on Security and …, Jan 1, 2008

We present a new class of statistical deanonymization attacks against high-dimensional micro-data... more We present a new class of statistical deanonymization attacks against high-dimensional micro-data, such as individual preferences, recommendations, transaction records and so on. Our techniques are robust to perturbation in the data and tolerate some mistakes in the adversary's background knowledge.

Abstract: While the Internet was conceived as a decentralized network, the most widely used web a... more Abstract: While the Internet was conceived as a decentralized network, the most widely used web applications today tend toward centralization. Control increasingly rests with centralized service providers who, as a consequence, have also amassed unprecedented amounts of data about the behaviors and personalities of individuals.

The ease of large-scale data collection. Before the growth of the Internet, collection of data fr... more The ease of large-scale data collection. Before the growth of the Internet, collection of data from individuals on a national or global scale was feasible only for governments and very large corporations. The infrastructure required for collecting and aggregating data was either in the form of a door-to-door survey as in a census, or a pervasive physical presence, such as a large supermarket chain collecting data on people's shopping habits.

Secret sharing is a very important primitive in cryptography and distributed computing. In this w... more Secret sharing is a very important primitive in cryptography and distributed computing. In this work, we consider computational secret sharing (CSS) which provably allows a smaller share size (and hence greater efficiency) than its information-theoretic counterparts. Extant CSS schemes result in succinct share-size and are in a few cases, like threshold access structures, optimal.

Abstract We study the problem of circuit obfuscation, ie, transforming the circuit in a way that ... more Abstract We study the problem of circuit obfuscation, ie, transforming the circuit in a way that hides everything except its input-output behavior. Barak et al. showed that a universal obfuscator that obfuscates every circuit class cannot exist, leaving open the possibility of special-purpose obfuscators.

Abstract We study techniques for identifying an anonymous author via linguistic stylometry, ie, c... more Abstract We study techniques for identifying an anonymous author via linguistic stylometry, ie, comparing the writing style against a corpus of texts of known authorship. We experimentally demonstrate the effectiveness of our techniques with as many as 100,000 candidate authors. Given the increasing availability of writing samples online, our result has serious implications for anonymity and free speech-an anonymous blogger or whistleblower may be unmasked unless they take steps to obfuscate their writing style.

We consider the problem of reliable message transmission between two synchronous players connecte... more We consider the problem of reliable message transmission between two synchronous players connected by n wires, some t < n/2 of which may be faulty. We show how to get reliability "for free"-reliable transmission of b bits involves a total communication of only O(b) bits, when b is large enough. We also construct an efficient Perfectly Secure Message Transmission Protocol.

We propose an efficient and robust Pay TV scheme for the case when there are a number of streams,... more We propose an efficient and robust Pay TV scheme for the case when there are a number of streams, as opposed to just one. In our model, the broadcast is divided into billing periods; during each billing period the entitlement of the users does not change. We achieve full flexibility with only a constant factor data redundancy. Our scheme has very little secure memory requirements and does not require the users' secure keys to be changed once they have been written into the secure memory.

Abstract We study privacy-preserving tests for proximity: Alice can test if she is close to Bob w... more Abstract We study privacy-preserving tests for proximity: Alice can test if she is close to Bob without either party revealing any other information about their location. We describe several secure protocols that support private proximity testing at various levels of granularity. We study the use of “location tags” generated from the physical environment in order to strengthen the security of proximity testing. We implemented our system on the Android platform and report on its effectiveness.

In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players ... more In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players (or processors), the Sender S and the Receiver R are connected by n wires (each of which facilitates 2-way communication); S has an ℓ-bit message that he wishes to send to R; after exchanging messages in phasesA phase is a send from S to R or from R\ bf R to S\ bf S or both simultaneously.

… and Privacy (SP), …, Jan 1, 2011

Many commercial websites use recommender systems to help customers locate products and content. M... more Many commercial websites use recommender systems to help customers locate products and content. Modern recommenders are based on collaborative filtering: they use patterns learned from users' behavior to make recommendations, usually in the form of related-items lists. The scale and complexity of these systems, along with the fact that their outputs reveal only relationships between items (as opposed to information about users), may suggest that they pose no meaningful privacy risk.

Communications of the ACM, Jan 1, 2010

Arxiv preprint arXiv:1102.4374, Jan 1, 2011

This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.c... more This paper describes the winning entry to the IJCNN 2011 Social Network Challenge run by Kaggle.com. The goal of the contest was to promote research on realworld link prediction, and the dataset was a graph obtained by crawling the popular Flickr social photo sharing website, with user identities scrubbed. By de-anonymizing much of the competition test set using our own Flickr crawl, we were able to effectively game the competition. Our attack represents a new application of de-anonymization to gaming machine learning contests, suggesting changes in how future competitions should be run.

Communications of the ACM, Jan 1, 2010

… of the 12th ACM conference on …, Jan 1, 2005

We investigate whether it is possible to encrypt a database and then give it away in such a form ... more We investigate whether it is possible to encrypt a database and then give it away in such a form that users can still access it, but only in a restricted way. In contrast to conventional privacy mechanisms that aim to prevent any access to individual records, we aim to restrict the set of queries that can be feasibly evaluated on the encrypted database.

17th Annual Network & …, Jan 1, 2010

Online behavioral advertising (OBA) refers to the practice of tracking users across web sites in ... more Online behavioral advertising (OBA) refers to the practice of tracking users across web sites in order to infer user interests and preferences. These interests and preferences are then used for selecting ads to present to the user. There is great concern that behavioral advertising in its present form infringes on user privacy. The resulting public debate -which includes consumer advocacy organizations, professional associations, and government agencies -is premised on the notion that OBA and privacy are inherently in conflict.

… of the 12th ACM conference on …, Jan 1, 2005

Human-memorable passwords are a mainstay of computer security. To decrease vulnerability of passw... more Human-memorable passwords are a mainstay of computer security. To decrease vulnerability of passwords to bruteforce dictionary attacks, many organizations enforce complicated password-creation rules and require that passwords include numerals and special characters. We demonstrate that as long as passwords remain human-memorable, they are vulnerable to "smart-dictionary" attacks even when the space of potential passwords is large.

… 30th IEEE Symposium on Security and …, Jan 1, 2009

Operators of online social networks are increasingly sharing potentially sensitive information ab... more Operators of online social networks are increasingly sharing potentially sensitive information about users and their relationships with advertisers, application developers, and data-mining researchers. Privacy is typically protected by anonymization, i.e., removing names, addresses, etc.

2008 IEEE Symposium on Security and …, Jan 1, 2008

We present a new class of statistical deanonymization attacks against high-dimensional micro-data... more We present a new class of statistical deanonymization attacks against high-dimensional micro-data, such as individual preferences, recommendations, transaction records and so on. Our techniques are robust to perturbation in the data and tolerate some mistakes in the adversary's background knowledge.