Further developments in generating type-safe messaging

At ICALEPCS '09, we introduced a source code generator that allows processes to communicate safely using data types native to each host language. In this paper, we discuss further development that has occurred since the conference in Kobe, Japan, including the addition of three more client languages, an optimization in network packet size and the addition of a new protocol data type.Comment: 4 pp. 13th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2011). 10-14 Oct 2011. Grenoble, Franc

Modeling and Testing Implementations of Protocols with Complex Messages

This paper presents a new language called APSL for formally describing protocols to facilitate automated testing. Many real world communication protocols exchange messages whose structures are not trivial, e.g. they may consist of multiple and nested fields, some could be optional, and some may have values that depend on other fields. To properly test implementations of such a protocol, it is not sufficient to only explore different orders of sending and receiving messages. We also need to investigate if the implementation indeed produces correctly formatted messages, and if it responds correctly when it receives different variations of every message type. APSL's main contribution is its sublanguage that is expressive enough to describe complex message formats, both text-based and binary. As an example, this paper also presents a case study where APSL is used to model and test a subset of Courier IMAP email server

PALPAS - PAsswordLess PAssword Synchronization

Tools that synchronize passwords over several user devices typically store the encrypted passwords in a central online database. For encryption, a low-entropy, password-based key is used. Such a database may be subject to unauthorized access which can lead to the disclosure of all passwords by an offline brute-force attack. In this paper, we present PALPAS, a secure and user-friendly tool that synchronizes passwords between user devices without storing information about them centrally. The idea of PALPAS is to generate a password from a high entropy secret shared by all devices and a random salt value for each service. Only the salt values are stored on a server but not the secret. The salt enables the user devices to generate the same password but is statistically independent of the password. In order for PALPAS to generate passwords according to different password policies, we also present a mechanism that automatically retrieves and processes the password requirements of services. PALPAS users need to only memorize a single password and the setup of PALPAS on a further device demands only a one-time transfer of few static data.Comment: An extended abstract of this work appears in the proceedings of ARES 201

A DAQ System for Linear Collider TPC Prototypes based on the ALEPH TPC Electronics

Within the international studies of a high energy linear electron positron collider, several groups are developing and testing prototypes for a Linear Collider TPC. This detector is planned to be used as a central part in the tracking system of a detector at such a machine. In this note we describe a DAQ system, which has been developed for the use in tests of TPC prototypes. It is based on electronics used at the ALEPH experiment at CERN.Comment: 15 pages, 4 figure

Intrinsic Quantum Computation

We introduce ways to measure information storage in quantum systems, using a recently introduced computation-theoretic model that accounts for measurement effects. The first, the quantum excess entropy, quantifies the shared information between a quantum process's past and its future. The second, the quantum transient information, determines the difficulty with which an observer comes to know the internal state of a quantum process through measurements. We contrast these with von Neumann entropy and quantum entropy rate and provide a closed-form expression for the latter for the class of deterministic quantum processes.Comment: 5 pages, 1 figure, 1 table; updated with corrections; http://cse.ucdavis.edu/~cmg/compmech/pubs/iqc.ht

Formal Verification of Probabilistic SystemC Models with Statistical Model Checking

Transaction-level modeling with SystemC has been very successful in describing the behavior of embedded systems by providing high-level executable models, in which many of them have inherent probabilistic behaviors, e.g., random data and unreliable components. It thus is crucial to have both quantitative and qualitative analysis of the probabilities of system properties. Such analysis can be conducted by constructing a formal model of the system under verification and using Probabilistic Model Checking (PMC). However, this method is infeasible for large systems, due to the state space explosion. In this article, we demonstrate the successful use of Statistical Model Checking (SMC) to carry out such analysis directly from large SystemC models and allow designers to express a wide range of useful properties. The first contribution of this work is a framework to verify properties expressed in Bounded Linear Temporal Logic (BLTL) for SystemC models with both timed and probabilistic characteristics. Second, the framework allows users to expose a rich set of user-code primitives as atomic propositions in BLTL. Moreover, users can define their own fine-grained time resolution rather than the boundary of clock cycles in the SystemC simulation. The third contribution is an implementation of a statistical model checker. It contains an automatic monitor generation for producing execution traces of the model-under-verification (MUV), the mechanism for automatically instrumenting the MUV, and the interaction with statistical model checking algorithms.Comment: Journal of Software: Evolution and Process. Wiley, 2017. arXiv admin note: substantial text overlap with arXiv:1507.0818