As Extensible Markup Language (XML) is emerging as the data format of the In-ternet era, there are increasing needs to eeciently store and query XML data. One path to this goal is transforming XML data into relational format in order to use relational database technology. Although several transformation algorithms exist, they are incomplete in the sense that they focus only on structural aspect...

Order-preserving encryption (OPE) preserves the order of data in their ciphertexts and, hence, allows range search on the encrypted data without needing to decrypt them. Security analysis of OPE schemes is very important because OPE is not a perfect encryption algorithm (the ciphertexts leak the ordering information of the plaintexts). Most of the existing security analysis for the OPE schemes ...

We present a new, high-level approach for the specification of model-to-model transformations based on declarative patterns. These are (atomic or composite) constraints on triple graphs declaring the allowed or forbidden relationships between source and target models. In this way, a transformation is defined by specifying a set of triple graph constraints that should be satisfied by the result ...

In this paper, we introduce the notion of an orientation-preserving transformation on arbitrary chain, as a natural extension for infinite chains well known concept finite introduced in 1998 by McAlister and, independently, 1999 Catarino and Higgins. We consider monoid POP(X)(X) all partial transformations or chain X its submonoids POPI(X) full permutations X, respectively. The OPPO(X) order-pr...