Analysis Of Cryptographic Protocols Research Articles

Cryptoeconomics: Financial Market Security Aspects and Implications for Managerial Accounting

"The development of modern information technologies and the processes of globalization are key factors for the emergence and spread of virtual currency. The legal status of cryptocurrency is still uncertain. It is considered both as a modern means of payment and as a speculative tool for illegal activities. However, despite such diametrically opposed interpretations, the fact that economic realities are constantly changing is unconditional. The IFRS reporting system is no exception, which should adapt to new challenges in a timely manner and take into account the need to disclose information about new progressive elements as much as possible. The article aims to analyze the economic and financial essence of cryptocurrencies, assess the phenomenon of the crypto economy and its impact on the financial market and monetary policy, as well as to outline appropriate implications for the corporate level – namely, for management accounting. The methodology is based on a theoretical analysis of cryptographic protocols and tools for investment and macroeconomic analysis, some approaches of economic theory. It is shown that although today cryptocurrency is a speculative, high-risk instrument, cryptoeconomics is increasingly integrating into the global financial market, while the potential risks of this process still outweigh its benefits. Accordingly, at the micro-level, management accountants must understand the related risks and be able to explain the implications to the management team and the board of directors. The originality of research consists of an attempt to combine the analysis of macro- and micro-implications of emerging crypto economics based on an economic theory foundation."

Decision and Complexity of Dolev-Yao Hyperproperties

The formal analysis of cryptographic protocols traditionally focuses on trace and equivalence properties, for which decision procedures in the symbolic (or Dolev-Yao, or DY) model are known. However, many relevant security properties are expressed as DY hyperproperties that involve quantifications over both execution paths and attacker computations (which are constrained by the attacker's knowledge in the underlying model of computation). DY hyperproperties generalise hyperproperties, for which many decision procedures exist, to the setting of DY models. Unfortunately, the subtle interactions between both forms of quantifications have been an obstacle to lifting decision procedures from hyperproperties to DY hyperproperties. The central contribution of the paper is the first procedure for deciding DY hyperproperties, in the usual setting where the number of protocol sessions is bounded and where the equational theory modelling cryptography is subterm-convergent. We prove that our decision procedure can decide the validity of any hyperproperty in which quantifications over messages are guarded and quantifications over attacker computations are limited to expressing the attacker's knowledge. We also establish the complexity of the decision problem for several important fragments of the hyperlogic. Further, we illustrate the techniques and scope of our contributions through examples of related hyperproperties.

LπCET: A Logic Security Analysis for Cryptographic Protocols Based on π‐Calculus Extension Theory

The π‐calculus is a basic theory of mobile communication based on the notion of interaction, which, is aimed at analyzing and modeling the behaviors of communication processes in communicating and mobile systems, and is widely applied to the security analysis of cryptographic protocol’s design and implementation. But the π‐calculus does not provide seamless logical security analysis, so the logical flaws in the design and the implementation of a cryptographic protocol cannot be discovered in time. This paper introduces logical rules and logical proofs, binary tree, and the KMP algorithm and proposes a new extension of the π‐calculus theory, a logical security analysis method, and an algorithm. The aim is to analyze whether there are logical flaws in the design and the implementation of a cryptographic protocol, to ensure the security of the cryptographic protocol when it is encoded into software and implemented. This paper presents the logical security proof and analysis of the TLS1.3 protocol’s interactional implementation process. Empirical results show that the additional extension theory, the logical security analysis method, and the algorithm can effectively analyze whether there are logical flaws in the design and the implementation of a cryptographic protocol.

An efficient canonical narrowing implementation with irreducibility and SMT constraints for generic symbolic protocol analysis

Narrowing and unification are very useful tools for symbolic analysis of rewrite theories, and thus for any model that can be specified in that way. A very clear example of their application is the field of formal cryptographic protocol analysis, which is why narrowing and unification are used in tools such as Maude-NPA, Tamarin and Akiss. In this work we present the implementation of a canonical narrowing algorithm, which improves the standard narrowing algorithm, extended to be able to process rewrite theories with conditional rules. The conditions of the rules will contain SMT constraints, which will be carried throughout the execution of the algorithm to determine if the solutions have associated satisfiable or unsatisfiable constraints, and in the latter case, discard them.

Universally Composable Security

This work presents a general framework for describing cryptographic protocols and analyzing their security. The framework allows specifying the security requirements of practically any cryptographic task in a unified and systematic way. Furthermore, in this framework the security of protocols is preserved under a general composition operation, called universal composition. The proposed framework with its security-preserving composition operation allows for modular design and analysis of complex cryptographic protocols from simpler building blocks. Moreover, within this framework, protocols are guaranteed to maintain their security in any context, even in the presence of an unbounded number of arbitrary protocol sessions that run concurrently in an adversarially controlled manner. This is a useful guarantee, which allows arguing about the security of cryptographic protocols in complex and unpredictable environments such as modern communication networks.

The IITM Model: A Simple and Expressive Model for Universal Composability

The universal composability paradigm allows for the modular design and analysis of cryptographic protocols. It has been widely and successfully used in cryptography. However, devising a coherent yet simple and expressive model for universal composability is, as the history of such models shows, highly non-trivial. For example, several partly severe problems have been pointed out in the literature for the UC model. In this work, we propose a coherent model for universal composability, called the IITM model (“Inexhaustible Interactive Turing Machine”). A main feature of the model is that it is stated without a priori fixing irrelevant details, such as a specific way of addressing of machines by session and party identifiers, a specific modeling of corruption, or a specific protocol hierarchy. In addition, we employ a very general notion of runtime. All reasonable protocols and ideal functionalities should be expressible based on this notion in a direct and natural way, and without tweaks, such as (artificial) padding of messages or (artificially) adding extra messages. Not least because of these features, the model is simple and expressive. Also the general results that we prove, such as composition theorems, hold independently of how such details are fixed for concrete applications. Being inspired by other models for universal composability, in particular the UC model and because of the flexibility and expressivity of the IITM model, conceptually, results formulated in these models directly carry over to the IITM model.

Bounded ACh unification

AbstractWe consider the problem of the unification modulo an equational theory associativity and commutativity (ACh), which consists of a function symbol h that is homomorphic over an associative–commutative operator +. Since the unification modulo ACh theory is undecidable, we define a variant of the problem called bounded ACh unification. In this bounded version of ACh unification, we essentially bound the number of times h can be applied to a term recursively and only allow solutions that satisfy this bound. There is no bound on the number of occurrences of h in a term, and the + symbol can be applied an unlimited number of times. We give inference rules for solving the bounded version of the problem and prove that the rules are sound, complete, and terminating. We have implemented the algorithm in Maude and give experimental results. We argue that this algorithm is useful in cryptographic protocol analysis.

Introduction to the special issue: Unification

In the days of its foundation, the field of science covered by UNIF – a series of annual international workshops on unification – was still in its infancy. With the advent of automated reasoning, term rewriting, logic programming, natural language processing, and program analysis, the areas of computer science concerned by unification were seething with excitement. With the coming out of researches in constraint solving and admissibility of inference rules and with the breaking out of applications, such as type checking, query answering, and cryptographic protocol analysis, the development of unification was not long in going at full speed.

A Universally Composable Key Exchange Protocol for Advanced Metering Infrastructure in the Energy Internet

The increasing adoption of multiway communications in the advanced metering infrastructure (AMI) of the energy Internet, which is known as the Internet-based smart grid, raises a new question about the security of customers' sensitive data and how the data can be protected from growing cyber attacks such as side-channel and false data injection attacks. The dynamic nature of remote connect/disconnect of components in the AMI also brings new types of security threats. To achieve secure multiway communications and remote connect/disconnect of components, the AMI requires a key exchange protocol (KEP) that meets a number of its security requirements such as confidentiality, integrity, availability, identification, authentication, and access control. In this context, in this article we present a KEP that uses an ideal crypto functionality and an ideal AMI key exchange functionality based on universal composability, which allows modular design and analysis of cryptographic protocols. The former functionality enables AMI components or users to perform authenticated cryptographic operations, while the later functionality enables the users to meet the AMI security requirements before generating a shared secret session key, which can be used in an ideal manner. We carry out experiments to validate the performance of our protocol, and the results show that our protocol offers better performance benefits compared to the existing related protocols and is suitable for the Energy Internet. We further demonstrate the usefulness of our ideal functionalities as a security reinforcement for a widely used KEP, namely the Elliptic Curve Diffie-Hellman.

Security Analysis of Wireless Authentication Protocols

Background & Objective: Cryptographic protocols had been evident method for ensuring con dentiality, Integrity and authentication in various digital communication systems. However the validation and analysis of such cryptographic protocols was limited to usage of formal mathematical models until few years back. Methods: In this paper, various popular cryptographic protocols have been studied. Some of these protocols (PAP, CHAP, and EAP) achieve security goals in peer to peer communication while others (RADIUS, DIAMETER and Kerberos) can work in multiparty environment. These protocols were validated and analysed over two popular security validation and analysis tools AVISPA and Scyther. The protocols were written according to their documentation using the HLPSL and SPDL for analysis over AVISPA and Scyther respectively. The results of these tools were analysed to nd the possible attack an each protocol. Afterwards The execution time analysis of the protocols were done by repeating the experiment for multiple iterations over the command line versions of these tools.As the literature review suggested, this research also validates that using password based protocols (PAP) is faster in terms of execution time as compared to other methods, Usage of nonces tackles the replay attack and DIAMETER is secure than RADIUS. Results and Conclusion: The results also showed us that DIAMETER is faster than RADIUS. Though Kerberos protocol was found to safe, the results tell us that it is compromisable under particular circumstances.

Analysis of Cryptographic Protocol by Dynamic Epistemic Logic

The security of the cryptographic protocols has always been important to ensure proper implementation of a protocol. To assure protocol security, a number of works for analysis and verification of cryptographic protocols have emerged in the literature. In this paper, with dynamic epistemic logic, we propose a model approach to analyze a cryptographic protocol. In order to capture the security properties of the protocol, we present the update of the epistemic states based on the epistemic actions. The epistemic actions lead to changes in the knowledge set of the agents participating in the protocol. We model this execution process of the specific example of the cryptographic protocol using the Kripke models and the transition between states. The result of analysis demonstrates that this cryptographic protocol conforms to the security requirements.

Simple and Tight Device-Independent Security Proofs

Device-independent security is the gold standard for quantum cryptography: not only is security based entirely on the laws of quantum mechanics, but it holds irrespective of any a priori assumptions on the quantum devices used in a protocol, making it particularly applicable in a quantum-wary environment. While the existence of device-independent protocols for tasks such as randomness expansion and quantum key distribution has recently been established, the underlying proofs of security remain very challenging, yield rather poor key rates, and demand very high-quality quantum devices, thus making them all but impossible to implement in practice. We introduce a technique for the analysis of device-independent cryptographic protocols. We provide a flexible protocol and give a security proof that provides quantitative bounds that are asymptotically tight, even in the presence of general quantum adversaries. At a high level our approach amounts to establishing a reduction to the scenario in which the untrusted device operates in an identical and independent way in each round of the protocol. This is achieved by leveraging the sequential nature of the protocol, and makes use of a newly developed tool, the "entropy accumulation theorem" of Dupuis et al. As concrete applications we give simple and modular security proofs for device-independent quantum key distribution and randomness expansion protocols based on the CHSH inequality. For both tasks we establish essentially optimal asymptotic key rates and noise tolerance. In view of recent experimental progress, which has culminated in loophole-free Bell tests, it is likely that these protocols can be practically implemented in the near future.

Security & privacy column

The present column continues our excursion in cryptographic protocol analysis . Here Stephanie Delaune presents the exciting research challenges behind her recent ERC Starting Grant "POPSTAR: reasoning about physical properties of security protocols with an application to contactless systems". The overall research goal is to develop techniques and tools to analyse protocols that establish and rely on properties of the physical world, such as distance bounding protocols, contactless payment systems, etc. While the hope is to leverage the extraordinary results arising from years of research in cryptographic protocol analysis, formally characterizing physical properties in communication protocols is a fascinating challenge that demands novel solutions.

Task-structured probabilistic I/O automata

Modeling frameworks such as Probabilistic I/O Automata (PIOA) and Markov Decision Processes permit both probabilistic and nondeterministic choices. In order to use these frameworks to express claims about probabilities of events, one needs mechanisms for resolving nondeterministic choices. For PIOAs, nondeterministic choices have traditionally been resolved by schedulers that have perfect information about the past execution. However, these schedulers are too powerful for certain settings, such as cryptographic protocol analysis, where information must sometimes be hidden. In this paper, we propose a new, less powerful nondeterminism-resolution mechanism for PIOAs, consisting of tasks and local schedulers. Tasks are equivalence classes of system actions that are scheduled by oblivious, global task sequences. Local schedulers resolve nondeterminism within system components, based on local information only. The resulting task-PIOA framework yields simple notions of external behavior and implementation, a new kind of simulation relation that is sound for proving implementation, and supports simple compositionality results.

A largely self-contained and complete security proof for quantum key distribution

In this work we present a security analysis for quantum key distribution, establishing a rigorous tradeoff between various protocol and security parameters for a class of entanglement-based and prepare-and-measure protocols. The goal of this paper is twofold: 1) to review and clarify the stateof-the-art security analysis based on entropic uncertainty relations, and 2) to provide an accessible resource for researchers interested in a security analysis of quantum cryptographic protocols that takes into account finite resource effects. For this purpose we collect and clarify several arguments spread in the literature on the subject with the goal of making this treatment largely self-contained. More precisely, we focus on a class of prepare-and-measure protocols based on the Bennett-Brassard (BB84) protocol as well as a class of entanglement-based protocols similar to the Bennett-Brassard-Mermin (BBM92) protocol. We carefully formalize the different steps in these protocols, including randomization, measurement, parameter estimation, error correction and privacy amplification, allowing us to be mathematically precise throughout the security analysis. We start from an operational definition of what it means for a quantum key distribution protocol to be secure and derive simple conditions that serve as sufficient condition for secrecy and correctness. We then derive and eventually discuss tradeoff relations between the block length of the classical computation, the noise tolerance, the secret key length and the security parameters for our protocols. Our results significantly improve upon previously reported tradeoffs.

Verification of Implementations of Cryptographic Hash Functions

Cryptographic hash functions have become the basis of modern network computing for identity authorization and secure computing; protocol consistency of cryptographic hash functions is one of the most important properties that affect the security and correctness of cryptographic implementations, and protocol consistency should be well proven before being applied in practice. Software verification has seen substantial application in safety-critical areas and has shown the ability to deliver better quality assurance for modern software; thus, applying software verification to a protocol consistency proof for cryptographic hash functions is a reasonable approach to prove their correctness. Verification of protocol consistency of cryptographic hash functions includes modeling of the cryptographic protocol and program analysis of the cryptographic implementation; these require a dedicated cryptographic implementation model that preserves the semantics of the code, efficient analysis of cryptographic operations on arrays and bits, and the ability to verify large-scale implementations. In this paper, we propose a fully automatic software verification framework, VeriHash, that brings software verification to protocol consistency proofs for cryptographic hash function implementations. It solves the above challenges by introducing a novel cryptographic model design for modeling the semantics of cryptographic hash function implementations, extended array theories for analysis of operations, and compositional verification for scalability. We evaluated our verification framework on two SHA-3 cryptographic hash function implementations: the winner of the NIST SHA-3 competition, Keccack; and an open-source hash program, RHash. We successfully verified the core parts of the two implementations and reproduced a bug in the published edition of RHash.

Quantum random oracle model for quantum digital signature

The goal of this work is to provide a general security analysis tool, namely, the quantum random oracle (QRO), for facilitating the security analysis of quantum cryptographic protocols, especially protocols based on quantum one-way function. QRO is used to model quantum one-way function and different queries to QRO are used to model quantum attacks. A typical application of quantum one-way function is the quantum digital signature, whose progress has been hampered by the slow pace of the experimental realization. Alternatively, we use the QRO model to analyze the provable security of a quantum digital signature scheme and elaborate the analysis procedure. The QRO model differs from the prior quantum-accessible random oracle in that it can output quantum states as public keys and give responses to different queries. This tool can be a test bed for the cryptanalysis of more quantum cryptographic protocols based on the quantum one-way function.

Intruder deducibility constraints with negation. Decidability and application to secured service compositions

We consider a problem of automated orchestration of security-aware services under additional constraints. The problem of finding a mediator to compose secured services has been reduced in previous works to the problem of solving deducibility constraints similar to those employed for cryptographic protocol analysis. We extend in this paper the mediator synthesis procedure (i.e. a solution for the orchestration problem) by allowing additional non-disclosure policies that express the fact that some data is not accessible to the mediator at a given point of its execution. We present a decision procedure that answers the question whether a mediator satisfying these policies can be effectively synthesized. The approach presented in this work extends the constraint solving procedure for cryptographic protocol analysis in a significant way as to be able to handle negation of deducibility constraints. It applies to all subterm convergent theories and therefore covers several interesting theories in formal security analysis including encryption, hashing, signature and pairing; it is also expressive enough for some RBAC policies. A variant of this procedure for Dolev Yao theory has been implemented in Cl-Atse, a protocol analysis tool based on constraint solving.

Reachability, confluence, and termination analysis with state-compatible automata

Regular tree languages are a popular device for reachability analysis over term rewrite systems, with many applications like analysis of cryptographic protocols, or confluence and termination analysis. At the heart of this approach lies tree automata completion, first introduced by Genet for left-linear rewrite systems. Korp and Middeldorp introduced so-called quasi-deterministic automata to extend the technique to non-left-linear systems. In this paper, we introduce the simpler notion of state-compatible automata, which are slightly more general than quasi-deterministic, compatible automata. This notion also allows us to decide whether a regular tree language is closed under rewriting, a problem which was not known to be decidable before.The improved precision has a positive impact in applications which are based on reachability analysis, namely termination and confluence analysis.Our results have been formalized in the theorem prover Isabelle/HOL. This allows to certify automatically generated proofs that are using tree automata techniques.

On the analysis of time-aware protocols in universal composability framework

We consider the analysis of time-aware cryptographic protocols in the universal composability (UC) framework (Canetti in 2000). The tasks we consider are the timeliness of messages within an instance as well as the time of validity of cryptographic credentials where the lifetime of time stamps overlaps lots of instances. We point out that the UC analysis of time-aware protocols with global access to real time clock cannot be carried out directly within the standard model. For the resolution of the corresponding problem, we considered two ways: one is the introduction of an auxiliary timing oracle into the ideal system, while the other consists of two time models: a quantized real time source and an abstract "random-time" source, and we show an essential equivalence between them. The time models provide not only theoretical but also practical benefits.