Octavian Catrina

Polytechnic University of Bucharest | UPB · Department of Telecommunications

Secure computation provides cryptographic protocols for collaborative applications with private inputs and outputs. In this paper, we examine a collection of protocols for secure evaluation of polynomials using secure floating-point arithmetic. The main goal is to provide a comparative analysis of their construction, complexity, performance, and tr...

Cryptographic Algorithms and Protocols. Table of Contents

The development of privacy preserving collaborative applications can be simplified by starting with a collection of protocols that support secure computation with all basic data types and secure and efficient protocol composition. For some tasks, secure computation with real numbers can be efficiently achieved using fixed-point arithmetic. However,...

The development of privacy preserving collaborative applications can be simplified by starting with a collection of protocols that support secure computation with all basic data types and secure and efficient protocol composition. For some tasks, secure computation with real numbers can be efficiently achieved using fixed-point arithmetic. However,...

As part of security and privacy threats modelling process, the systematic identification, definition and analysis of threats is important to accurately highlight the resources that would ultimately play a critical role in achieving the organization’s business objectives. We show how we proceeded to identify and formalize the security threats based...

Secure computation supports collaborative applications with private inputs and outputs, by providing cryptographic protocols that protect data privacy during the computation. Important applications, like statistical analysis, benchmarking, data mining, and optimizations, require accurate and efficient secure computation with floating-point numbers....

A broad range of privacy preserving collaborative applications require efficient and accurate secure computation with real numbers (e.g., statistical analysis, data mining, and optimizations). Secure fixed-point arithmetic offers efficient solutions for certain tasks, but many applications require the dynamic range and accuracy provided by floating...

Successful deployment of privacy preserving collaborative applications, like statistical analysis, benchmarking, and optimizations, requires more efficient secure computation with real numbers. We present a complete family of protocols for secure floating-point arithmetic, constructed using a small set of building blocks that preserve data privacy...

Computation with private data has been successfully demonstrated for various collaborative applications. However, meeting the requirements of real-life applications still requires major improvements of the protocols' performance and functionality. We extend a secure computation framework with new building blocks and optimizations that provide impor...

Secure multiparty computation provides specially designed cryptographic protocols for collaborative applications with private inputs and outputs. Computing with private data has been successfully demonstrated for some real-life applications. However, meeting the application requirements still requires major improvements of the protocols' performanc...

Secure multiparty computation provides specially designed cryptographic protocols for collaborative applications with private inputs and outputs. Computing with private data has been successfully demonstrated for some real-life applications. However, meeting the application requirements still requires major improvements of the protocols' performanc...

Video streaming services need a server selection algorithm that allocates efficiently network and server resources. Solving this optimization problem requires information about current resources. A video streaming system that relies entirely on the service provider for this task needs an expensive monitoring infrastructure. In this paper, we consid...

The SecureSCM project demonstrates the practical applicability of secure multiparty computation to online business collaboration. A prototype supply-chain management system protects the confidentiality of private data while rapidly adapting to changing business needs.

We consider a collection of related multiparty computation protocols that provide core operations for secure integer and fixed-point computation. The higher-level protocols offer integer truncation and comparison, which are typically the main performance bottlenecks in complex applications. We present techniques and building blocks that allow to im...

Collaborative optimization problems can often be modeled as a linear program whose objective function and constraints combine data from several parties. However, important applications of this model (e.g., supply chain planning) involve private data that the parties cannot reveal to each other. Traditional linear programming methods cannot be used...

Secure computation is a promising approach to business problems in which several parties want to run a joint application and cannot reveal their inputs. Secure computation preserves the privacy of input data using cryptographic protocols, allowing the parties to obtain the benefits of data sharing and at the same time avoid the associated risks. Th...

Collaborative business applications can use secure multiparty computation to preserve input privacy. These applications need protocols that provide all the basic operations with integers and rational numbers and allow secure composition and efficient application development. Secure computation with rational numbers is a long-standing open problem....

The SecureSCM project (www.securescm.org) aims to develop cryptographic solutions to the problem of data sharing in Supply Chain Optimization (SCO). The SCO problem has a precise mathematical structure. It is an instance of the general Linear Programming (LP) problem. However, standard techniques for LP problems are not suitable for this purpose be...

Secure multiparty computation (SMC) protocols enable a group of mutually distrustful parties to perform a joint computation with private inputs. Novel e-commerce applications have emerged that could benefit from strong privacy protection, e.g., benchmarking, auctions, and collaborative supply chain management and planning. However, the uptake of SM...

During the decade that has elapsed since its standardisation by ISO, the Estelle formal description technique has been successfully applied to the development of various communications protocols. We present in this paper a protocol engineering methodology that has resulted from the use of Estelle in several projects, involving the specification, va...

We present a validation method that uses guided simulation for a functional decomposition of the system's behaviour. Essential aspects of the behaviour are expressed as dependence relations between events. They are used to jointly specify guiding constraints, delimiting the simulated functionality, and correctness requirements, describing the expec...

With the advent of effective techniques and tools, the industrial use of the formal methods for telecommuni-cation systems development is rapidly extending. At the same time, the diversity of the applications determines a continuous search for new methods. This paper presents a new approach for expressing the correctness requirements and the valida...

The main challenges for the tools which derive implementations from formal descriptions are to enhance the efficiency and facilitate the integration in various implementation contexts. We study in this paper the Estelle based implementations. Using the Estelle Development Toolset (EDT), we obtained a realistic implementation of a complex transport...

The Xpress transport protocol (XTP) is designed to meet the needs of distributed, real-time, and multimedia systems. This paper describes the genesis of recent improvements to XTP that provide mechanisms for reliable management of multicast groups, and gives details of the mechanisms used.

The paper presents methods for protocol analysis and verification, based on the observation of simulations of a formal description, written in Estelle. The methods were experimented during the development of an Estelle specification for the new definition of the Xpress Transport Protocol (XTP), revision 4.0. Starting from a set of proposed modifica...

C and C++ programming

We present a validation method that uses guided simulation for a functional decomposition of the system's behaviour. Essential aspects of the behaviour are expressed as depend-ence relations between events. They are used to jointly specify guiding constraints, delimiting the simulated func-tionality, and correctness requirements, describing the exp...