Gwan-Hwan Hwang

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Concurrent programs are more diicult to test than sequential programs because of nondeterministic behavior. An execution of a concurrent program non-deterministically exercises a sequence of synchronization events, called a synchronization sequence (or SYN-sequence). Nondeterministic testing of a concurrent program P is to execute P with a given input many(More)
In this paper we present an operational model for XML document security. Given an XML document X, the operational model defines the process of encrypting data and embedding digital signatures which sign the data in X. The secured XML document Xs includes encrypted and unencrypted data of X, and embedded digital signatures. The operational model also defines(More)
In this paper we define and explore proof of violation (POV) for cloud storage systems. A POV scheme enables a user or a service provider to produce a precise proof of either the occurrence of the violation of properties or the innocence of the service provider. POV schemes are solutions for obtaining mutual nonrepudiation between users and the service(More)
Establishing scalable and cross-enterprise workflow management systems (WfMSs) in the cloud requires the adaptation and extension of existing concepts for process management. This paper proposes a scalable and cross-enterprise WfMS with a multitenancy architecture. Especially, it can activate enactment of workflow processes by cloud collaboration. We do not(More)
In this paper, we propose solution for obtaining mutual nonrepudiation between the user and service provider in cloud storage. One of the solutions for mutual nonrepudiation is based on logging attestations, which are signed messages. For supporting write-serializability and read freshness of files, an intuitive solution is to have attestations be chain(More)
An increasing number of programming languages, such as Fortran 90 and APL, are providing a rich set of intrinsic array functions and array expressions. These constructs which constitute an important part of data parallel languages provide excellent opportunities for compiler optimizations. In this paper, we present a new approach to combine consecutive data(More)
An increasing number of programming languages, such as Fortran 90, HPF, and APL, are providing a rich set of intrinsic array functions and array expressions. These constructs which constitute an important part of data parallel languages provide excellent opportunities for compiler optimizations. The synthesis of consecutive array operations or array(More)
The Chinese wall security model (CWSM) was designed to provide access controls that mitigate conflict of interest in commercial organizations, and is especially important for large-scale interenterprise workflow applications. This paper describes how to implement the CWSM in a WfMS. We first demonstrate situations in which the role-based access control(More)
An increasing number of programming languages, such as Fortran 90 and APL, are providing a rich set of intrinsic array functions and array expressions. These constructs which constitute an important part of data parallel languages provide excellent opportunities for compiler optimizations. In this paper, we present a new approach to combine consecutive(More)