1,292 research outputs found
Efficient algorithms for pairing-based cryptosystems
We describe fast new algorithms to implement recent cryptosystems based on the Tate pairing. In particular, our techniques improve pairing evaluation speed by a factor of about 55 compared to previously known methods in characteristic 3, and attain performance comparable
to that of RSA in larger characteristics.We also propose faster algorithms for scalar multiplication in characteristic 3 and square root extraction
over Fpm, the latter technique being also useful in contexts other than that of pairing-based cryptography
The implementation of mentalization-based treatment for adolescents: a case study from an organizational, team and therapist perspective
Privacy protection in electronic education based on polymorphic pseudonymization
In [13.] Dutch government proposes an identity scheme supporting personal data exchange of pupils with private e-textbook publishers.
This design propagates sharing personal numbers of pupils among private parties violating the data minimisation principle in privacy laws. We describe a privacy friendly alternative, giving pupils (and parents) control on exchange of their personal data.
Three generic forms based on homomorphic encryption are used as building blocks. These forms do not yield personal numbers, or even personal data from a legal perspective, and have strong, unlinkability properties. Only if required a school provides a party with a party-specific {\em pseudonym} identifying a pupil. For this the school is provided an {\em encrypted pseudonym} by a central party based on a {\em polymorphic pseudonym} formed by the school. Only intended parties, not even schools, have access to pseudonyms. Different publishers can send pupil test results to a school without being able to assess whether pupils are identical.
We also describe support for privacy friendly attributes and user inspection as required by privacy laws
Activate Later Certificates for V2X -- Combining ITS efficiency with privacy
We specify Issue First Activate Later (IFAL). This is an ETSI type of V2X Public Key Infrastructure based on short-lived pseudonymous certificates without Certificate Revocation Lists. IFAL certificates are valid in the future but can only be used together with periodically provided activation codes. IFAL supports controlled de-pseudonymization enabling provisioning to stop for misbehaving vehicles.
IFAL allows for flexible policies, trade-offs between three essential V2X properties: trust, privacy and usability. IFAL activation codes are small and can be sent in an SMS, through roadside equipment or even broadcasted. Like the Butterfly scheme, IFAL uses key derivation with one base private/public key pair. However in IFAL the security module can be simple as it can be kept oblivious of key derivation
Explaining engagement levels of opportunity and necessity entrepreneurs
This paper investigates
differences between opportunity and necessity entrepreneurs in terms of
socio-demographics, attitudes and perception of obstacles . We use the
2004 Flash Eurobarometer Survey data. Explanatory variables include
gender, age, education level and self-employed parents, risk tolerance,
locus of control, perceptions of four obstacles and country effects. The
obstacle variables include the perception of availibility of financial
support; administrative complexity; of access to information on new
venture creation and an unfavorable economic climate. Using probit
equations we investigate differences in the preference for self-employment
of opportunity and necessity entrepreneurs. A probit equation is estimated
relating the explanatory variables to opportunity versus necessity
entrepreneurship. Moreover, differences in the entrepreneurial engagement
of opportunity and necessity entrepreneurs are investigated on the basis
of a (ordered) multinomial logit model. Findings indicate that opportunity
entrepreneurs have a higher preference for self-employment because of
family encouragement. Also, opportunity entrepreneurs are found to
perceive of administrative complexity and an unfavorable economic climate,
negatively influencing their entrepreneurial involvement, while this is
not the case for necessity entrepreneurs
Reliability and validity of the Dutch dimensional assessment of personality pathology-short form(DAPP-SF), a shortened version of the DAPP-Basic questionnaire
The Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ) appears to be a good choice for the assessment of personality pathology. However, due to its length, administration of the instrument is rather time-consuming, hindering standard inclusion of the DABB-BQ in a battery of assessment instruments at intake. We developed the 136-item DAPP-SF (Short Form), and investigated its psychometric characteristics in various samples, i.e., a community-based sample (n = 487), patients with mood-, anxiety-, and somatoform disorders (n = 1,329), and patients with personality disorders (n = 1,393). Results revealed high internal consistency for almost all dimensions. The factor structure appeared almost identical as compared to the factor structure of the original DAPP-BQ, and was shown to be invariant across the various patient and community samples. Indices for convergent, discriminant and criterion related validity were satisfactory. It is concluded that the good psychometric characteristics of the original DAPP-BQ were preserved in the shortened version of the instrument
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