Modular composition and verification of transaction processing protocols using category theory

Establishing the correctness of reliable distributed protocols supporting dependable applications necessitates modular/compositional approaches to tackle the inherent complexity of these protocols. Efforts involved in the specification and verification of these reliable distributed protocols can be considerably reduced if the protocol is composed utilizing smaller components (building-blocks) possessing individual functionalities that are integral parts of the overall protocol operation. In this thesis, we introduce techniques utilizing the concepts of category theory for the modular composition of dependable distributed protocols. In particular, we show how by defining external interfaces of basic modules, and morphisms linking two different modules, a larger or more complex protocol can be formally composed and verified. To illustrate the effectiveness of the proposed methodology for compositional specification and verification, in this thesis, we present a modular composition and verification of a transaction processing protocol namely the non-blocking atomic three phase commit (3PC) protocol using category theoretic concepts. Specifically, we illustrate how the overall global properties of the protocol can be proved by utilizing constructs of local sub-properties of the inherent building blocks of the 3PC protocol. A key benefit of this modular approach is that these identified building blocks would be helpful to system designers for their capability of specifying and facilitating rigorously tested and pretested formal theory modules of required system and component behavior; and also supporting system design decisions and modifications

Designing Software Architectures As a Composition of Specializations of Knowledge Domains

This paper summarizes our experimental research and software development activities in designing robust, adaptable and reusable software architectures. Several years ago, based on our previous experiences in object-oriented software development, we made the following assumption: ‘A software architecture should be a composition of specializations of knowledge domains’. To verify this assumption we carried out three pilot projects. In addition to the application of some popular domain analysis techniques such as use cases, we identified the invariant compositional structures of the software architectures and the related knowledge domains. Knowledge domains define the boundaries of the adaptability and reusability capabilities of software systems. Next, knowledge domains were mapped to object-oriented concepts. We experienced that some aspects of knowledge could not be directly modeled in terms of object-oriented concepts. In this paper we describe our approach, the pilot projects, the experienced problems and the adopted solutions for realizing the software architectures. We conclude the paper with the lessons that we learned from this experience

Ensuring Logistics Integrity: An Ethereum Framework

In this study, we examine the potential benefits and difficulties of integrating blockchain technology based on Ethereum into logistics management systems. Our goal is to offer a thorough grasp of this technology's influence on the logistics sector by looking at its theoretical underpinnings and real-world implementations. Significant outcomes from our research include greater logistic transparency, real-time updates, increased security, and automation of contractual duties. These findings underscore the need to embrace innovation and create a legislative framework that facilitates the implementation of blockchain technology, with broad ramifications for logistics firms and legislators. Our study adds to the expanding corpus of information on the application of blockchain technology in logistics, offering insightful information to scholars, policymakers, and business professionals

C4: Verified Transactional Objects

A framework for Verified Transactional Objects in Coq. - Formalization of concurrent objects, linearizability, strict serializability, and associated proof techniques. - Verified linearizable concurrent hash map - Verified strictly serializable TML - Verified strictly serializable transaction-predicated ma

Multi-instance publicly verifiable time-lock puzzle and its applications

Time-lock puzzles are elegant protocols that enable a party to lock a message such that no one else can unlock it until a certain time elapses. Nevertheless, existing schemes are not suitable for the case where a server is given multiple instances of a puzzle scheme at once and it must unlock them at different points in time. If the schemes are naively used in this setting, then the server has to start solving all puzzles as soon as it receives them, that ultimately imposes significant computation cost and demands a high level of parallelisation. We put forth and formally define a primitive called “multi-instance time-lock puzzle” which allows composing a puzzle’s instances. We propose a candidate construction: “chained time-lock puzzle” (C-TLP). It allows the server, given instances’ composition, to solve puzzles sequentially, without having to run parallel computations on them. C-TLP makes black-box use of a standard time-lock puzzle scheme and is accompanied by a lightweight publicly verifiable algorithm. It is the first time-lock puzzle that offers a combination of the above features. We use C-TLP to build the first “outsourced proofs of retrievability” that can support real-time detection and fair payment while having lower overhead than the state of the art. As another application of C-TLP, we illustrate in certain cases, one can substitute a “verifiabledelay function” with C-TLP, to gain much better efficiency

Chainspace: A Sharded Smart Contracts Platform

Chainspace is a decentralized infrastructure, known as a distributed ledger, that supports user defined smart contracts and executes user-supplied transactions on their objects. The correct execution of smart contract transactions is verifiable by all. The system is scalable, by sharding state and the execution of transactions, and using S-BAC, a distributed commit protocol, to guarantee consistency. Chainspace is secure against subsets of nodes trying to compromise its integrity or availability properties through Byzantine Fault Tolerance (BFT), and extremely high-auditability, non-repudiation and `blockchain' techniques. Even when BFT fails, auditing mechanisms are in place to trace malicious participants. We present the design, rationale, and details of Chainspace; we argue through evaluating an implementation of the system about its scaling and other features; we illustrate a number of privacy-friendly smart contracts for smart metering, polling and banking and measure their performance

Functionally Specified Distributed Transactions in Co-operative Scenarios

Addresses the problem of specifying co-operative, distributed transactions in a manner that can be subject to verification and testing. Our approach combines the process-algebraic language LOTOS and the object-oriented database modelling language TM to obtain a clear and formal protocol for distributed database transactions meant to describe co-operation scenarios. We argue that a separation of concerns, namely the interaction of database applications on the one hand and data modelling on the other, results in a practical, modular approach that is formally well-founded. An advantage of this is that we may vary over transaction models to support the language combinatio