In this paper we consider the first order discrete Hamiltonian systems {x1（n＋1）-x1（n）=Hx2（n,x（n））,x2（n）-x2（n-1）=Hx1（n,x（n））,where x（n） = （x2（n）x1（n））∑ R^2N, H（n,z） = 1/2S（n）z. z ＋ R（n,z...In this paper we consider the first order discrete Hamiltonian systems {x1（n＋1）-x1（n）=Hx2（n,x（n））,x2（n）-x2（n-1）=Hx1（n,x（n））,where x（n） = （x2（n）x1（n））∑ R^2N, H（n,z） = 1/2S（n）z. z ＋ R（n,z） is periodic in n and superlinear as {z} →4 ∞. We prove the existence and infinitely many （geometrically distinct） homoclonic orbits of the system by critical point theorems for strongly indefinite functionals.展开更多
This paper studies the existence of nontrival homoclinic orbits of the Hamiltonian systems -L(t)q+V′(t,q)=0 by using the critical point theory, where the potential V(t,q)=b(t)W(q) can change sign. Under a new kind of...This paper studies the existence of nontrival homoclinic orbits of the Hamiltonian systems -L(t)q+V′(t,q)=0 by using the critical point theory, where the potential V(t,q)=b(t)W(q) can change sign. Under a new kind of "superquadratic" condition on W, some new results are obtained.展开更多
Commitment scheme is a basic component of many cryptographic protocols, such as coin-tossing, identification schemes, zero-knowledge and multi-party computation. In order to prevent man-in-middle attacks, non-malleabi...Commitment scheme is a basic component of many cryptographic protocols, such as coin-tossing, identification schemes, zero-knowledge and multi-party computation. In order to prevent man-in-middle attacks, non-malleability is taken into account. Many forming works focus on designing non-malleable commitments schemes based on number theory assumptions. In this paper we give a general framework to construct non- interactive and non-malleable commitment scheme with respect to opening based on more general assumptions called q-one way group homomorphisms (q-OWGH). Our scheme is more general since many existing commitment schemes can be deduced from our scheme.展开更多
基金CHEN WenXiong supported by Science Foundation of Huaqiao UniversityYANG Minbo was supported by Natural Science Foundation of Zhejiang Province (Grant No. Y7080008)+1 种基金YANG Minbo was supported by National Natural Science Foundation of China (Grant No. 11101374, 10971194)DING Yanheng was supported partially by National Natural Science Foundation of China (Grant No. 10831005)
文摘In this paper we consider the first order discrete Hamiltonian systems {x1（n＋1）-x1（n）=Hx2（n,x（n））,x2（n）-x2（n-1）=Hx1（n,x（n））,where x（n） = （x2（n）x1（n））∑ R^2N, H（n,z） = 1/2S（n）z. z ＋ R（n,z） is periodic in n and superlinear as {z} →4 ∞. We prove the existence and infinitely many （geometrically distinct） homoclonic orbits of the system by critical point theorems for strongly indefinite functionals.
文摘This paper studies the existence of nontrival homoclinic orbits of the Hamiltonian systems -L(t)q+V′(t,q)=0 by using the critical point theory, where the potential V(t,q)=b(t)W(q) can change sign. Under a new kind of "superquadratic" condition on W, some new results are obtained.
基金the National Natural Science Foundations of China (Nos. 60673079 and 60572155)
文摘Commitment scheme is a basic component of many cryptographic protocols, such as coin-tossing, identification schemes, zero-knowledge and multi-party computation. In order to prevent man-in-middle attacks, non-malleability is taken into account. Many forming works focus on designing non-malleable commitments schemes based on number theory assumptions. In this paper we give a general framework to construct non- interactive and non-malleable commitment scheme with respect to opening based on more general assumptions called q-one way group homomorphisms (q-OWGH). Our scheme is more general since many existing commitment schemes can be deduced from our scheme.
