Compact Signatures for Network Coding (2009)
Network coding offers increased throughput and improved robustness to random faults in completely decentralized networks. Since it does not require centralized control, network coding has been...
John Bethencourt, Dawn Song, Brent Waters
A system for private stream searching, introduced by Ostrovsky and Skeith, allows a client to provide an untrusted server with an encrypted search query. The server uses the query on a stream of...
Analysis-Resistant Malware (2009)
John Bethencourt, Dawn Song, Brent Waters
SRI International Traditionally, techniques for computing on encrypted data have been proposed with privacy preserving applications in mind. Several current cryptosystems support a homomorphic...
Revocation Systems with Very Small Private Keys (2009)
In this work, we design a new public key broadcast encryption system, and we focus on a critical parameter of device key size: the amount of the cryptographic key material that must be stored...
Adaptive Security in Broadcast Encryption Systems (2009)
We present new techniques for achieving adaptive security in broadcast encryption systems. Previous work on fully collusion resistant broadcast encryption with short ciphertexts was limited to...
Compact Proofs of Retrievability (2009)
In a proof-of-retrievability system, a data storage center must prove to a verifier that he is actually storing all of a client’s data. The central challenge is to build systems that are both...
Delegating Capabilities in Predicate Encryption Systems (2009)
In predicate encryption systems, given a capability, one can evaluate one or more predicates on the encrypted data, while all other information about the plaintext remains hidden. We consider the...
We present new techniques for realizing Ciphertext-Policy Attribute Encryption (CP-ABE) under concrete and noninteractive cryptographic assumptions. Our solutions allow any encryptor to specify...
Signing a Linear Subspace: Signature Schemes for Network Coding (2009)
Dan Boneh, David Freeman, Jonathan Katz, Brent Waters
Abstract. Network coding offers increased throughput and improved robustness to random faults in completely decentralized networks. In contrast to traditional routing schemes, however, network coding...
Predicate Encryption Supporting Disjunctions, Polynomial Equations, and Inner Products (2008)
Jonathan Katz, Amit Sahai, Brent Waters
Abstract. Predicate encryption is a new paradigm generalizing, among other things, identity-based encryption. In a predicate encryption scheme, secret keys correspond to predicates and ciphertexts...
My research interests fall broadly in the categories of network security and cryptography. I am particularly interested in designing novel cryptographic algorithms for the purpose of building secure...
SRI International Abstract (2008)
We propose a new general primitive called lossy trapdoor functions (lossy TDFs), and realize it under a variety of different number theoretic assumptions, including hardness of the decisional...
Key Terms – Before we move on… • Password Multiplier – • The implementation in contention. (2008)
J. Alex Halderman, Brent Waters, Edward W. Felten
• A hash function is a reproducible (deterministic) method of turning some kind of data into a (relatively) small number that may serve as a digital "fingerprint " of the data....
Xavier Boyen, Hovav Shacham, Brent Waters, Emily Shen
In most forward-secure signature constructions, a program that updates a user’s private signing key must have full access to the private key. Unfortunately, these schemes are incompatible with...
Predicate Encryption Supporting Disjunctions, Polynomial Equations, and Inner Products (2008)
Jonathan Katz, Amit Sahai, Brent Waters
Predicate encryption is a new paradigm generalizing, among other things, identity-based encryption. In a predicate encryption scheme, secret keys correspond to predicates and ciphertexts are...
SRI International Abstract (2008)
We propose a new general primitive called lossy trapdoor functions (lossy TDFs), and realize it under a variety of different number theoretic assumptions, including hardness of the decisional...
ABSTRACT New Client Puzzle Outsourcing Techniques for DoS Resistance (2008)
Brent Waters, Ari Juels, J. Alex Halderman, Edward W. Felten
We explore new techniques for the use of cryptographic puzzles as a countermeasure to Denial-of-Service (DoS) attacks. We propose simple new techniques that permit the outsourcing of puzzles—their...
New Client Puzzle Outsourcing Techniques (2008)
For Dos Resistance, Brent Waters, Ari Juels, J. Alex Halderman, Edward W. Felten
We explore new techniques for the use of cryptographic puzzles as a countermeasure to Denial-of-Service (DoS) attacks. We propose simple new techniques that permit the outsourcing of puzzles---their...
Compact Proofs of Retrievability (2008)
In a proof-of-retrievability system, a data storage center must prove to a verifier that he is actually storing all of a client’s data. The central challenge is to build systems that are both...
We propose a general cryptographic primitive called lossy trapdoor functions (lossy TDFs), and use it to develop new approaches for constructing several important cryptographic tools, including...
Predicate encryption supporting disjunctions, polynomial equations, and inner products (2008)
Jonathan Katz, Amit Sahai, Brent Waters
Predicate encryption is a new paradigm for public-key encryption generalizing, among other things, identity-based encryption. In a predicate encryption scheme, secret keys correspond to predicates...
Full-domain subgroup hiding and constant-size group signatures (2007)
We give a short constant-size group signature scheme, which we prove fully secure under reasonable assumptions in bilinear groups, in the standard model. We achieve this result by using a new NIZK...
Full-domain subgroup hiding and constant-size group signatures (2007)
Abstract We give a short constant-size group signature scheme, which we prove fully secure underreasonable assumptions in bilinear groups, in the standard model. We achieve this result by using a new...
Xavier Boyen, Hovav Shacham, Emily Shen, Brent Waters
In most forward-secure signature constructions, a program that updates a user’s private signing key must have full access to the private key. Unfortunately, these schemes are incompatible with...
Attribute-based encryption with non-monotonic access structures (2007)
Rafail Ostrovsky, Amit Sahai, Brent Waters
We construct an Attribute-Based Encryption (ABE) scheme that allows a user’s private key to be expressed in terms of any access formula over attributes. Previous ABE schemes were limited to...
Conjunctive, subset, and range queries on encrypted data (2007)
We construct public-key systems that support comparison queries (x ≥ a) on encrypted data as well as more general queries such as subset queries (x ∈ S). These systems support arbitrary...
Full-domain subgroup hiding and constant-size group signatures (2007)
Abstract. We give a short constant-size group signature scheme, which we prove fully secure under reasonable assumptions in bilinear groups, in the standard model. We achieve this result by using a...
New Techniques for Private Stream Searching (2006)
Bethencourt, John, Song, Dawn, Waters, Brent
A system for private stream searching, introduced by Ostrovsky and Skeith, allows a client to provide an untrusted server with an encrypted search query. The server uses the query on a stream of...
Abstract. We describe the first efficient ring signature scheme secure, without random oracles, based on standard assumptions. Our ring signatures are based in bilinear groups. For l members of a...
Xavier Boyen, Hovav Shacham, Emily Shen, Brent Waters
In most forward-secure signature constructions, a program that updates a user’s private signing key must have full access to the private key. Unfortunately, these schemes are incompatible with...
Xavier Boyen, Qixiang Mei, Brent Waters
We describe a new encryption technique that is secure in the standard model against adaptive chosen ciphertext (CCA2) attacks. We base our method on two very efficient Identity-Based Encryption (IBE)...
New techniques for private stream searching (2006)
John Bethencourt, Dawn Song, Brent Waters
A system for private stream searching, introduced by Ostrovsky and Skeith [18], allows a client to provide an untrusted server with an encrypted search query. The server uses the query on a stream of...
Steve Lu, Hovav Shacham, Rafail Ostrovsky, Amit Sahai, Brent Waters
We present the first aggregate signature, the first multisignature, and the first verifiably encrypted signature provably secure without random oracles. Our constructions derive from a novel...
New techniques for private stream searching (2006)
John Bethencourt, Dawn Song, Brent Waters
A system for private stream searching, introduced by Ostrovsky and Skeith [18], allows a client to provide an untrusted server with an encrypted search query. The server uses the query on a stream of...
Fully Collusion Resistant Traitor Tracing with Short Ciphertexts and Private Keys (2006)
Dan Boneh, Amit Sahai, Brent Waters
We construct a fully collusion resistant tracing traitors system with sublinear size ciphertexts and constant size private keys. More precisely, let N be the total number of users. Our system...
Anonymous Hierarchical Identity-Based Encryption (without Random Oracles) (2006)
We present an identity-based cryptosystem that features fully anonymous ciphertexts and hierarchical key delegation. We give a proof of security in the standard model, based on the mild Decision...
Privacy in Encrypted Content Distribution Using Private Broadcast Encryption (2006)
Adam Barth, Dan Boneh, Brent Waters
In many content distribution systems it is important to both restrict access of content to authorized users and to protect the identities of these users. We discover that current systems for...
Sequential Aggregate Signatures and Multisignatures without Random Oracles (2006)
Steve Lu, Rafail Ostrovsky, Amit Sahai, Hovav Shacham, Brent Waters
We present the first aggregate signature, the first multisignature, and the first verifiably encrypted signature provably secure without random oracles. Our constructions derive from a novel...
Conjunctive, Subset, and Range Queries on Encrypted Data (2006)
We construct public-key systems that support comparison queries (x a) on encrypted data as well as more general queries such as subset queries (x S). These systems also support arbitrary conjunctive...
Efficient Ring Signatures without Random Oracles (2006)
We describe the first e#cient ring signature scheme secure, without random oracles, based on standard assumptions. Our ring signatures are based in bilinear groups. For l members of a ring our...
Forward-Secure Signatures with Untrusted Update (2006)
Xavier Boyen, Hovav Shacham, Emily Shen, Brent Waters
In most forward-secure signature constructions, a program that updates a user's private signing key must have full access to the private key. Unfortunately, these schemes are incompatible with...
A Fully Collusion Resistant Broadcast, Trace, and Revoke System (2006)
We introduce a simple primitive called Augmented Broadcast Encryption (ABE) that is sufficient for constructing broadcast encryption, traitor-tracing, and trace-and-revoke systems. These ABE-
Sequential Aggregate Signatures and Multisignatures without Random Oracles (2006)
Steve Lu, Hovav Shacham, Rafail Ostrovsky, Amit Sahai, Brent Waters
We present the first aggregate signature, the first multisignature, and the first verifiably encrypted signature provably secure without random oracles. Our constructions derive from a novel...
We describe the first efficient ring signature scheme secure, without random oracles, based on standard assumptions. Our ring signatures are based in bilinear groups. For l members of a ring our...
Strongly unforgeable signatures based on computational Diffie-Hellman (2006)
Dan Boneh, Emily Shen, Brent Waters
Abstract. A signature system is said to be strongly unforgeable if the signature is existentially unforgeable and, given signatures on some message m the adversary cannot produce a new signature on...
Anonymous hierarchical identity-based encryption (without random oracles (2006)
Abstract We present an identity-based cryptosystem that features fully anonymous ciphertexts andhierarchical key delegation. We give a proof of security in the standard model, based on the mild
Anonymous hierarchical identity-based encryption (without random oracles (2006)
We present an identity-based cryptosystem that features fully anonymous ciphertexts and hierarchical key delegation. We give a proof of security in the standard model, based on the mild Decision...
Strongly unforgeable signatures based on computational Diffie-Hellman (2006)
Dan Boneh, Emily Shen, Brent Waters
Abstract. A signature system is said to be strongly unforgeable if the signature is existentially unforgeable and, given signatures on some message m, the adversary cannot produce a new signature on...
Steve Lu, Hovav Shacham, Rafail Ostrovsky, Amit Sahai, Brent Waters
We present the first aggregate signature, the first multisignature, and the first verifiably encrypted signature provably secure without random oracles. Our constructions derive from a novel...
Sequential aggregate signatures and multisignatures without random oracles (2006)
Steve Lu, Rafail Ostrovsky, Amit Sahai, Hovav Shacham, Brent Waters
Abstract. We present the first aggregate signature, the first multisignature, and the first verifiably encrypted signature provably secure without random oracles. Our constructions derive from a...
B.: Privacy in encrypted content distribution using private broadcast encryption (2006)
Adam Barth, Dan Boneh, Brent Waters
Abstract. In many content distribution systems it is important both to restrict access to content to authorized users and to protect the identities of these users. We discover that current systems...
We describe the first efficient ring signature scheme secure, without random oracles, based on standard assumptions. Our ring signatures are based in bilinear groups. For l members of a ring our...
Efficient identity-based encryption without random oracles (2005)
We present the first efficient Identity-Based Encryption (IBE) scheme that is fully secure without random oracles. We first present our IBE construction and reduce the security of our scheme to the...
A Convenient Method for Securely Managing Passwords (2005)
J. Alex Halderman, Brent Waters, Edward W. Felten
Computer users are asked to generate, keep secret, and recall an increasing number of passwords for uses including host accounts, email servers, e-commerce sites, and online financial services....
Collusion Resistant Broadcast Encryption with Short Ciphertexts and Private Keys (2005)
Dan Boneh, Craig Gentry, Brent Waters
We describe two new public key broadcast encryption systems for stateless receivers. Both systems are fully secure against any number of colluders. In our first construction both ciphertexts and...
Compact Group Signatures without Random Oracles (2005)
We present the first e#cient group signature scheme that is provably secure without random oracles. We achieve this result by combining provably secure hierarchical signatures in bilinear groups with...
Direct Chosen Ciphertext Security from Identity-Based Techniques (2005)
Xavier Boyen, Qixiang Mei, Brent Waters
We describe a new encryption technique that is secure in the standard model against adaptive chosen ciphertext (CCA2) attacks. We base our method on two very e#cient Identity-Based Encryption (IBE)...
Collusion resistant broadcast encryption with short ciphertexts and private keys (2005)
Dan Boneh, Craig Gentry, Brent Waters
We describe two new public key broadcast encryption systems for stateless receivers. Both systems are fully secure against any number of colluders. In our first construction both ciphertexts and...
Direct chosen ciphertext security from identity-based techniques (2005)
Xavier Boyen, Qixiang Mei, Brent Waters
Abstract We describe a new encryption technique that is secure in the standard model against adaptivechosen ciphertext (CCA2) attacks. We base our method on two very efficient Identity-Based
Secure Conjunctive Keyword Search over Encrypted Data (2004)
Philippe Golle, Jessica Staddon, Brent Waters
We study the setting in which a user stores encrypted documents (e.g. e-mails) on an untrusted server. In order to retrieve documents satisfying a certain search criterion, the user gives the server...
New Client Puzzle Outsourcing Techniques for DoS Resistance (2004)
Brent Waters, John A. Halderman, Ari Juels, Edward W. Felten
We explore new techniques for the use of cryptographic puzzles as a countermeasure to Denial-of-Service (DoS) attacks.
Privacy Management for Portable Recording Devices (2004)
Alex Halderman Brent, Brent Waters, Edward W. Felten
The growing popularity of inexpensive, portable recording devices, such as cellular phone cameras and compact digital audio recorders, presents a significant new threat to privacy. We propose a set...
Privacy management for portable recording devices (2004)
J. Alex Halderman, Brent Waters, Edward W. Felten
The growing popularity of inexpensive, portable recording devices, such as cellular phone cameras and compact digital audio recorders, presents a significant new threat to privacy. We propose a set...
The family and reproductive technologies /--Brent Waters. (1999)
Thesis (D.Phil.)--University of Oxford, 1999.