Early PKI projects fell short in getting the critical mass of users subscribed because they were too expensive and to ambigious. Now, beyond the hype, there is a demand for improvement of security step by step rather than for big projects. Now, linking up existing PKI-islands, using S/MIME, introducing single sign-on and rising awareness are hot topics. Our vision, however, remains a globally a...

We describe an educational experience designed to teach Italian Sign Language (LIS) to a group of hearing children. The hypothesis underlying this experience was that learning a visual-gestural language such as LIS may improve children's attentional abilities, visual discrimination, and spatial memory. To examine this hypothesis, we conducted two studies. The first involved an educational exper...

An n × n complex sign pattern matrix S is said to be spectrally arbitrary if for every monic nth degree polynomial f(λ) with coefficients from C, there is a complex matrix in the complex sign pattern class of S such that its characteristic polynomial is f(λ). If S is a spectrally arbitrary complex sign pattern matrix, and no proper subpattern of S is spectrally arbitrary, then S is a minimal sp...

An n × n complex sign pattern matrix S is said to be spectrally arbitrary if for every monic nth degree polynomial f(λ) with coefficients from C, there is a complex matrix in the complex sign pattern class of S such that its characteristic polynomial is f(λ). If S is a spectrally arbitrary complex sign pattern matrix, and no proper subpattern of S is spectrally arbitrary, then S is a minimal sp...

interpretation: Domains and surroundings. Abstract interpretation is a general theory for specifying and designing approximate semantics of program languages [10]. Approximation can be equivalently formulated either in terms of Galois connections or closure operators [11]. An upper closure operator ρ : C → C on a poset C (uco(C ) for short), representing concrete objects, is monotone, idempoten...

Simple Sign & Encrypt, by itself, is not very secure. Cryptographers know this well, but application programmers and standards authors still tend to put too much trust in simple Sign-and-Encrypt. In fact, every secure e-mail protocol, old and new, has codi ed na ve Sign & Encrypt as acceptable security practice. S/MIME, PKCS#7, PGP, OpenPGP, PEM, and MOSS all su er from this aw. Similarly, the...