Trusted third party

About: Trusted third party is a research topic. Over the lifetime, 2919 publications have been published within this topic receiving 60935 citations.

TrustedPals: secure multiparty computation implemented with smart cards

Abstract: We study the problem of Secure Multi-party Computation (SMC) in a model where individual processes contain a tamper-proof security module, and introduce the TrustedPals framework, an efficient smart card based implementation of SMC for any number of participating entities in such a model. Security modules can be trusted by other processes and can establish secure channels between each other. However, their availability is restricted by their host, that is, a corrupted party can stop the computation of its own security module as well as drop any message sent by or to its security module. We show that in this model SMC can be implemented by reducing it to a fault-tolerance problem at the level of security modules. Since the critical part of the computation can be executed locally on the smart card, we can compute any function securely with a protocol complexity which is polynomial only in the number of processes (that is, the complexity does not depend on the function which is computed), in contrast to previous approaches.

Enterprise security system

Abstract: A platform of Trust Management software which is a single, customizable, complete distributed computing security solution designed to be integrated into an enterprise computing environment. Digital Network Authentication (DNA) is the centerpiece of the system of the present invention. It is a unique means to authenticate the identity of a communicating party and authorize its activity. The whole mechanism can be thought of as a trusted third party providing assurances to both clients and servers that each communicating entity is a discrete, authenticated entity with clearly defined privileges and supporting data. Furthermore, the level of trust to be placed in the authorization of every entity communicating within the system is communicated to every entity within a distributed computing environment.

How to build time-lock encryption

Abstract: Time-lock encryption is a method to encrypt a message such that it can only be decrypted after a certain deadline has passed. We propose a novel time-lock encryption scheme, whose main advantage over prior constructions is that even receivers with relatively weak computational resources should immediately be able to decrypt after the deadline, without any interaction with the sender, other receivers, or a trusted third party. We build our time-lock encryption on top of the new concept of computational reference clocks and an extractable witness encryption scheme. We explain how to construct a computational reference clock based on Bitcoin. We show how to achieve constant level of multilinearity for witness encryption by using SNARKs. We propose a new construction of a witness encryption scheme which is of independent interest: our scheme, based on Subset-Sum, achieves extractable security without relying on obfuscation. The scheme employs multilinear maps of arbitrary order and is independent of the implementations of multilinear maps.

A Semantic Framework for the Security Analysis of Ethereum smart contracts

Abstract: Smart contracts are programs running on cryptocurrency (e.g., Ethereum) blockchains, whose popularity stem from the possibility to perform financial transactions, such as payments and auctions, in a distributed environment without need for any trusted third party. Given their financial nature, bugs or vulnerabilities in these programs may lead to catastrophic consequences, as witnessed by recent attacks. Unfortunately, programming smart contracts is a delicate task that requires strong expertise: Ethereum smart contracts are written in Solidity, a dedicated language resembling JavaScript, and shipped over the blockchain in the EVM bytecode format. In order to rigorously verify the security of smart contracts, it is of paramount importance to formalize their semantics as well as the security properties of interest, in particular at the level of the bytecode being executed. In this paper, we present the first complete small-step semantics of EVM bytecode, which we formalize in the F* proof assistant, obtaining executable code that we successfully validate against the official Ethereum test suite. Furthermore, we formally define for the first time a number of central security properties for smart contracts, such as call integrity, atomicity, and independence from miner controlled parameters. This formalization relies on a combination of hyper- and safety properties. Along this work, we identified various mistakes and imprecisions in existing semantics and verification tools for Ethereum smart contracts, thereby demonstrating once more the importance of rigorous semantic foundations for the design of security verification techniques.

Systems and methods for validated secure data access

Abstract: Methods, systems, and techniques for securing access to stored data are provided. Example embodiments provide a Storage Management System (“SMS”) that is configured to facilitate protected information sharing. The SMS may restrict access to shared information based on one or more criteria that validate an entity's right to access the information. For example, the SMS may restrict access to entities that are located in a particular geographic region, that are using a particular type of hardware or software, that hold particular credentials, or the like. In some cases, the SMS may require that an entity's claim to meet on or more required criteria be validated by a trusted third party.