The impact of parent-created motivational climate on adolescent athletes' perceptions of physical self-concept

This is a preliminary version of this article. The official published version can be obtained from the link below.Grounded in expectancy-value model (Eccles, 1993) and achievement goal theory (Nicholls, 1989), this study examined the perceived parental climate and its impact on athletes' perceptions of competence and ability. Hierarchical regression analyses with a sample of 237 British adolescent athletes revealed that mothers and fathers' task- and ego-involving climate predicted their son's physical self-concept; the father in particular is the strongest influence in shaping a son's physical self-concept positively and negatively. It was also found that the self-concept of the young adolescent athlete is more strongly affected by the perceived parental-created motivational climate (both task and ego) than the older adolescent athlete's self-concept. These findings support the expectancy-value model assumptions related to the role of parents as important socializing agents, the existence of gender-stereotyping, and the heavy reliance younger children place on parents' feedback

Special Libraries, June 1921

Volume 12, Issue 6https://scholarworks.sjsu.edu/sla_sl_1921/1005/thumbnail.jp

Factors influencing the pursuit of health and science careers for Canadian adolescents in transition from school and work

Previous research separately acknowledges two emerging trends in adolescence but neglects to integrate them. These are that many changes have occurred in the school to work transitional processes, and that there is substantial need for adolescents, especially young women, to pursue science career pathways. In this study, we link these trends and develop predictive, interactive models of science pursuit for 836 Canadian secondary school graduates living through a period of massive change in school to work transitional processes. Separate logit analyses were conducted for males and females. Results suggest that young women are not under-represented in the pursuit of science careers in high school. Young women aspire more frequently to medical and health sciences, and young men to natural sciences, engineering and mathematics. For young women, father's occupation in science, curriculum track and level of occupational expectation were significant in the model, correctly predicting 72% of membership in science. For males, socioeconomic status, family support, level of occupational expectation, regional unemployment levels and items measuring work environment were significant in the model that predicted 81% of membership in science. The findings suggest the salience of gender-differentiated school to work transition models in determining pursuit of health and science career pathways

Efficient hidden vector encryption with constant-size ciphertext

A Hidden Vector Encryption (HVE) scheme is a special type of anonymous identity-based encryption (IBE) scheme where the attribute string associated with the ciphertext or the user secret key can contain wildcards. In this paper, we introduce two constant-size ciphertext-policy hidden vector encryption (CP-HVE) schemes. Our first scheme is constructed on composite order bilinear groups, while the second one is built on prime order bilinear groups. Both schemes are proven secure in a selective security model which captures plaintext (or payload) and attribute hiding. To the best of our knowledge, our schemes are the first HVE constructions that can achieve constant-size ciphertext among all the existing HVE schemes. 2014 Springer International Publishing Switzerland

Polynomial spaces: a new framework for composite to-prime-order transformations

Comunicació presentada a: CRYPTO 2014. 34th Annual Cryptology Conference, celebrada a Santa Barbara, Califòrnia, Estats Units d'Amèrica, del 17 al 21 d'agost de 2014At Eurocrypt 2010, Freeman presented a framework to convert cryptosystems based on composite-order groups into ones that use prime-order groups. Such a transformation is interesting not only from a conceptual point of view, but also since for relevant parameters, operations in prime-order groups are faster than composite-order operations by an order of magnitude. Since Freeman's work, several other works have shown improvements, but also lower bounds on the efficiency of such conversions. In this work, we present a new framework for composite-to-prime-order conversions. Our framework is in the spirit of Freeman's work; however, we develop a different, \polynomial" view of his approach, and revisit several of his design decisions. This eventually leads to significant e ciency improvements, and enables us to circumvent previous lower bounds. Specifically, we show how to verify Groth-Sahai proofs in a prime-order environment (with a symmetric pairing) almost twice as efficiently as the state of the art. We also show that our new conversions are optimal in a very broad sense. Besides, our conversions also apply in settings with a multilinear map, and can be instantiated from a variety of computational assumptions (including, e.g., the k-linear assumption).This work has been supported in part by DFG grant GZ HO 4534/4-1. Carla Ràfols was supported by a Sofja Kovalevskaja Award of the Alexander von Humboldt Foundation and the German Federal Ministry for Education and Research

Revocable Identity-Based Encryption Revisited: Security Model and Construction ∗

In ACM CCS 2008, Boldyreva et al. proposed an elegant way of achieving an Identity-based Encryption (IBE) with efficient revocation, which we call revocable IBE (RIBE). One of the significant benefit of their construction is scalability, where the overhead of the trusted authority is logarithmically increased in the number of users, whereas that in the Boneh-Franklin naive revocation way is linearly increased. All subsequent RIBE schemes follow the Boldyreva et al. security model and syntax. In this paper, we first revisit the Boldyreva et al. security model, and aim at capturing the exact notion for the security of the naive but non-scalable Boneh-Franklin RIBE scheme. To this end, we consider a realistic threat, which we call decryption key exposure. We also show that all prior RIBE constructions except for the Boneh-Franklin one are vulnerable to decryption key exposure. As the second contribution, we revisit approaches to achieve (efficient and adaptively secure) scalable RIBE schemes, and propose a simple RIBE scheme, which is the first scalable RIBE scheme with decryption key exposure resistance, and is more efficient than previous (adaptively secure) scalable RIBE schemes. In particular, our construction has the shortest ciphertext size and the fastest decryption algorithm even compared with all scalable RIBE schemes without decryption key exposure resistance

Efficient (Anonymous) Compact HIBE from Standard Assumptions

Abstract. We present two hierarchical identity-based encryption (HIBE) schemes, denoted as H1 and H2, from Type-3 pairings with constant sized ciphertexts. Scheme H1 achieves anonymity while H2 is non-anonymous. The constructions are obtained by extending the IBE scheme recently proposed by Jutla and Roy (Asiacrypt 2013). Security is based on the standard decisional Symmetric eXternal Diffie-Hellman (SXDH) assumption. In terms of provable security properties, previous direct constructions of constant-size ciphertext HIBE had one or more of the following drawbacks: security in the weaker model of selective-identity attacks; exponential security degradation in the depth of the HIBE; and use of non-standard assumptions. The security arguments for H1 and H2 avoid all of these drawbacks. These drawbacks can also be avoided by obtaining HIBE schemes by specialising schemes for hierarchical inner product encryption; the downside is that the resulting efficiencies are inferior to those of the schemes reported here. Currently, there is no known anonymous HIBE scheme having the security properties of H1 and comparable efficiency. An independent work by Chen and Wee describes a non-anonymous HIBE scheme with security claims and efficiency similar to that of H2; we note though that in comparison to H2, the Chen-Wee HIBE scheme has larger ciphertexts and less efficient encryption and decryption algorithms. Based on the current state-of-the-art, H1 and H2 are the schemes of choice for efficient implementation of (anonymous) HIBE constructions