Dining cryptographers problem

Abstract: The past two decades have seen a growing interest in methods for anonymous communication on the Internet, both from the academic community and the general public. Several system designs have been proposed in the literature, of which a number have been implemented and are used by diverse groups, such as journalists, human rights workers, the military, and ordinary citizens, to protect their identities on the Internet.In this work, we survey the previous research done to design, develop, and deploy systems for enabling private and anonymous communication on the Internet. We identify and describe the major concepts and technologies in the field, including mixes and mix networks, onion routing, and Dining Cryptographers networks. We will also review powerful traffic analysis attacks that have motivated improvements and variations on many of these anonymity protocols made since their introduction. Finally, we will summarize some of the major open problems in anonymous communication research and discuss possible directions for future work in the field.

Abstract: Dining cryptographers networks (or DC-nets) are a privacy-preserving primitive devised by Chaum for anonymous message publication. A very attractive feature of the basic DC-net is its non-interactivity. Subsequent to key establishment, players may publish their messages in a single broadcast round, with no player-to-player communication. This feature is not possible in other privacy-preserving tools like mixnets. A drawback to DC-nets, however, is that malicious players can easily jam them, i.e., corrupt or block the transmission of messages from honest parties, and may do so without being traced. Several researchers have proposed valuable methods of detecting cheating players in DC-nets. This is usually at the cost, however, of multiple broadcast rounds, even in the optimistic case, and often of high computational and/or communications overhead, particularly for fault recovery. We present new DC-net constructions that simultaneously achieve non-interactivity and high-probability detection and identification of cheating players. Our proposals are quite efficient, imposing a basic cost that is linear in the number of participating players. Moreover, even in the case of cheating in our proposed system, just one additional broadcast round suffices for full fault recovery. Among other tools, our constructions employ bilinear maps, a recently popular cryptographic technique for reducing communication complexity.

Abstract: The concept of anonymity comes into play in a wide range of situations, varying from voting and anonymous donations to postings on bulletin boards and sending mails. The systems for ensuring anonymity often use random mechanisms which can be described probabilistically, while the agents' interest in performing the anonymous action may be totally unpredictable, irregular, and hence expressable only nondeterministically.Formal definitions of the concept of anonymity have been investigated in the past either in a totally nondeterministic framework, or in a purely probabilistic one. In this paper, we investigate a notion of anonymity which combines both probability and nondeterminism, and which is suitable for describing the most general situation in which both the systems and the user can have both probabilistic and nondeterministic behavior. We also investigate the properties of the definition for the particular cases of purely nondeterministic users and purely probabilistic users.We formulate our notions of anonymity in terms of observables for processes in the probabilistic π-calculus, whose semantics is based on Probabilistic Automata. We illustrate our ideas by using the example of the dining cryptographers.

Abstract: Private Computation.- Efficient Private Matching and Set Intersection.- Positive Results and Techniques for Obfuscation.- Secure Computation of the k th -Ranked Element.- Signatures I.- Short Signatures Without Random Oracles.- Sequential Aggregate Signatures from Trapdoor Permutations.- Unconditional Security.- On the Key-Uncertainty of Quantum Ciphers and the Computational Security of One-Way Quantum Transmission.- The Exact Price for Unconditionally Secure Asymmetric Cryptography.- On Generating the Initial Key in the Bounded-Storage Model.- Distributed Cryptography.- Practical Large-Scale Distributed Key Generation.- Optimal Communication Complexity of Generic Multicast Key Distribution.- Foundations I.- An Uninstantiable Random-Oracle-Model Scheme for a Hybrid-Encryption Problem.- Black-Box Composition Does Not Imply Adaptive Security.- Identity-Based Encryption.- Chosen-Ciphertext Security from Identity-Based Encryption.- Efficient Selective-ID Secure Identity-Based Encryption Without Random Oracles.- Elliptic Curves.- Construction of Secure Random Curves of Genus 2 over Prime Fields.- Projective Coordinates Leak.- Signatures II.- Security Proofs for Identity-Based Identification and Signature Schemes.- Concurrent Signatures.- The Hierarchy of Key Evolving Signatures and a Characterization of Proxy Signatures.- Public-Key Cryptography.- Public-Key Steganography.- Immunizing Encryption Schemes from Decryption Errors.- Secure Hashed Diffie-Hellman over Non-DDH Groups.- Foundations II.- On Simulation-Sound Trapdoor Commitments.- Hash Function Balance and Its Impact on Birthday Attacks.- Multiparty Computation.- Multi-party Computation with Hybrid Security.- On the Hardness of Information-Theoretic Multiparty Computation.- Dining Cryptographers Revisited.- Cryptanalysis.- Algebraic Attacks and Decomposition of Boolean Functions.- Finding Small Roots of Bivariate Integer Polynomial Equations Revisited.- New Applications.- Public Key Encryption with Keyword Search.- Fuzzy Extractors: How to Generate Strong Keys from Biometrics and Other Noisy Data.- Algorithms and Implementation.- Merkle Tree Traversal in Log Space and Time.- Can We Trust Cryptographic Software? Cryptographic Flaws in GNU Privacy Guard v1.2.3.- Anonymity.- Traceable Signatures.- Handcuffing Big Brother: an Abuse-Resilient Transaction Escrow Scheme.- Anonymous Identification in Ad Hoc Groups.