Representing Isabelle in LF

LF has been designed and successfully used as a meta-logical framework to represent and reason about object logics. Here we design a representation of the Isabelle logical framework in LF using the recently introduced module system for LF. The major novelty of our approach is that we can naturally represent the advanced Isabelle features of type classes and locales. Our representation of type classes relies on a feature so far lacking in the LF module system: morphism variables and abstraction over them. While conservative over the present system in terms of expressivity, this feature is needed for a representation of type classes that preserves the modular structure. Therefore, we also design the necessary extension of the LF module system.Comment: In Proceedings LFMTP 2010, arXiv:1009.218

Isabelle Modelchecking for insider threats

The Isabelle Insider framework formalises the technique of social explanation for modeling and analysing Insider threats in infrastructures including physical and logical aspects. However, the abstract Isabelle models need some refinement to provide sufficient detail to explore attacks constructively and understand how the attacker proceeds. The introduction of mutable states into the model leads us to use the concepts of Modelchecking within Isabelle. Isabelle can simply accommodate classical CTL type Modelchecking. We integrate CTL Modelchecking into the Isabelle Insider framework. A running example of an IoT attack on privacy motivates the method throughout and illustrates how the enhanced framework fully supports realistic modeling and analysis of IoT Insiders

Investigating airplane safety and security against insider threats using logical modeling

In this paper we consider the limits of formal modeling of infrastructures and the application of social explanation for the analysis of insider threats in security and safety critical areas. As an area of study for the analysis we take examples from aviation, firstly since incidents are typically well-documented and secondly since it is an important area per se. In March 2015, a Germanwings flight crashed in the French Alps in what is quite firmly believed to have been intentionally caused by the copilot who locked the pilot out of the cockpit and programmed the autopilot on constant descent. We investigate the security controls and policies in airplanes against insider threats using logical modeling in Isabelle

Mechanizing the metatheory of sledgehammer

This paper presents an Isabelle/HOL formalization of recent research in automated reasoning: efficient encodings of sorts in unsorted first-order logic, as implemented in Isabelle’s Sledgehammer proof tool. The formalization provides the general-purpose machinery to reason about formulas and models, emulating the theory of institutions. Quantifiers are represented using a nominal-like approach designed for interpreting syntax in semantic domains

Mechanical analysis of finite idempotent relations

We use the technique of interactive theorem proving to develop the theory and anenumeration technique for finite idempotent relations. Starting from a short mathematical characterization of finite idempotents defined and proved in Isabelle/HOL, we derive first an iterative procedure to generate all instances of idempotents over a finite set. From there, we develop a more precise theo- retical characterization giving rise to an efficient predicate that can be executed in the programming language ML. Idempotent relations represent a very basic, general mathematical concept but the steps taken to develop their theory with the help of Isabelle/HOL are representative for developing algorithms from a mathematical specification

Isabelle Modelchecking for insider threats

The Isabelle Insider framework formalises the technique of social explanation for modeling and analysing Insider threats in infrastructures including physical and logical aspects. However, the abstract Isabelle models need some refinement to provide sufficient detail to explore attacks constructively and understand how the attacker proceeds. The introduction of mutable states into the model leads us to use the concepts of Modelchecking within Isabelle. Isabelle can simply accommodate classical CTL type Modelchecking. We integrate CTL Modelchecking into the Isabelle Insider framework. A running example of an IoT attack on privacy motivates the method throughout and illustrates how the enhanced framework fully supports realistic modeling and analysis of IoT Insiders

Inter-blockchain protocols with the Isabelle Infrastructure framework

The main incentives of blockchain technology are distribution and distributed change, consistency, and consensus. Beyond just being a distributed ledger for digital currency, smart contracts add transaction protocols to blockchains to execute terms of a contract in a blockchain network. Inter-blockchain (IBC) protocols define and control exchanges between different blockchains. The Isabelle Infrastructure framework has been designed to serve security and privacy for IoT architectures by formal specification and stepwise attack analysis and refinement. A major case study of this framework is a distributed health care scenario for data consistency for GDPR compliance. This application led to the development of an abstract system specification of blockchains for IoT infrastructures. In this paper, we first give a summary of the concept of IBC. We then introduce an instantiation of the Isabelle Infrastructure framework to model blockchains. Based on this we extend this model to instantiate different blockchains and formalize IBC protocols. We prove the concept by defining the generic property of global consistency and prove it in Isabelle

Inter-Blockchain Protocols with the Isabelle Infrastructure Framework

The main incentives of blockchain technology are distribution and distributed change, consistency, and consensus. Beyond just being a distributed ledger for digital currency, smart contracts add transaction protocols to blockchains to execute terms of a contract in a blockchain network. Inter-blockchain (IBC) protocols define and control exchanges between different blockchains. The Isabelle Infrastructure framework {has been designed to} serve security and privacy for IoT architectures by formal specification and stepwise attack analysis and refinement. A major case study of this framework is a distributed health care scenario for data consistency for GDPR compliance. This application led to the development of an abstract system specification of blockchains for IoT infrastructures. In this paper, we first give a summary of the concept of IBC. We then introduce an instantiation of the Isabelle Infrastructure framework to model blockchains. Based on this we extend this model to instantiate different blockchains and formalize IBC protocols. We prove the concept by defining the generic property of global consistency and prove it in Isabelle