A Verifiably Encrypted Signature (VES) plays an essential role in the construction of a fair data exchange. The paper proposes an Identity-based Proxy Verifiably Encrypted Signature (IPVES) to combine the advantages o...A Verifiably Encrypted Signature (VES) plays an essential role in the construction of a fair data exchange. The paper proposes an Identity-based Proxy Verifiably Encrypted Signature (IPVES) to combine the advantages of a proxy signature and a VES in order to delegate the signing capability of the VES of an entity called the original signer to another entity, called the proxy signer. In this IPVES scheme, the original signer delegates his/her signing capability to the proxy signer. The proxy signer issues a signature by using a proxy signing key, encrypts the signature under a designated public key, and subsequently convinces a verifier that the resulting ciphertext contains such a signature. We prove that the proposed IPVES scheme is secure in a random oracle model under the computational Diffie-Hellman assumption.展开更多
Identity-based （ID-based） ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are const...Identity-based （ID-based） ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.展开更多
Objective:Diffuse Large B Cell Lymphoma(DLBCL)is a heterogeneous group of tumors with different biological and clinical characteristics that have diverse clinical outcomes and response to therapy.Stromal-1 signature o...Objective:Diffuse Large B Cell Lymphoma(DLBCL)is a heterogeneous group of tumors with different biological and clinical characteristics that have diverse clinical outcomes and response to therapy.Stromal-1 signature of tumor microenvironment of DLBCL represents extracellular matrix deposition and histiocytic infiltrate,whereas stromal-2 represents angiogenesis that could affect tumor progression.Methods:The aim of the present study is to assess the significance of stromal-1 signature using SPARC-1 and stromal-2 signature using CD31 expression and then finally to construct biologic prognostic model(BPM)in 60 cases of DLBCL via immunohistochemistry.Results:Microvessel density(P<0.05)and SPARC percentage of expression(P<0.001)were higher in DLBCL,including germinal and nongerminal cases,compared with reactive follicular hyperplasia.High microvessel density was significantly associated with splenic involvement(P=0.008),high mitotic count(P=0.045),and presence of capsular invasion(P=0.035).Percentage of SPARC expression was significantly associated with splenic involvement(P=0.03).Constructing BPM showed that 42 cases(70%)were of low biologic score(0–1)and 18 cases(30%)were of high biologic score(2–3).Low BPM cases showed less probability for splenic involvement(P=0.04)and a higher rate of complete response to therapy compared with high score cases(P=0.08).Conclusions:The DLBCL microenvironment could modulate tumor progression behavior since angiogenesis and SPARC positive stromal cells promote dissemination by association with spleen involvement and capsular invasion.Biologic prognostic models,including modified BPM,which considered cell origin of DLBCL and stromal signature pathways,could determine DLBCL progression and response to therapy.展开更多
Due to the compromise of the security of the underlying system or machine stonng the key, exposure of the private key can be a devastating attack on a cryptosystem. Key insulation is an important technique to protect ...Due to the compromise of the security of the underlying system or machine stonng the key, exposure of the private key can be a devastating attack on a cryptosystem. Key insulation is an important technique to protect private keys. To deal with the private （signing） key exposure problem in identity-based signature systems, we propose an identity-based threshold key-insulated signature （IBTKIS） scheme. It strengthens the security and flexibility of existing identity-based key-insulated signature schemes. Our scheme＇ s security is proven in the random oracle model and rests on the hardness of the computational Diffie-Helhnan problem in groups equipped with a pairing. To the best of our knowledge, it is the first IBTKIS scheme up to now.展开更多
基金supported partially by the Projects of National Natural Science Foundation of China under Grants No.61272501 the National Key Basic Research Program （NK-BRP）（973 program）under Grant No.2012CB315900 the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20091102110004
文摘A Verifiably Encrypted Signature (VES) plays an essential role in the construction of a fair data exchange. The paper proposes an Identity-based Proxy Verifiably Encrypted Signature (IPVES) to combine the advantages of a proxy signature and a VES in order to delegate the signing capability of the VES of an entity called the original signer to another entity, called the proxy signer. In this IPVES scheme, the original signer delegates his/her signing capability to the proxy signer. The proxy signer issues a signature by using a proxy signing key, encrypts the signature under a designated public key, and subsequently convinces a verifier that the resulting ciphertext contains such a signature. We prove that the proposed IPVES scheme is secure in a random oracle model under the computational Diffie-Hellman assumption.
基金Supported by the National High Technology Research and Development Program of China (No. 2006AA01Z428)the National Natural Science Foundation of China ( No. 60673075)
文摘Identity-based （ID-based） ring signature has drawn great concerns in recent years and many ID-based ring signature schemes have been proposed until now. Unfortunately, all of these ID-based ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based ring signature without pairing is of great interest in the field of cryptography. In this paper, the authors firstly propose an ID-based ring signature scheme based on quadratic residues. The proposed scheme is proved to be existentially unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring. The proposed scheme is more efficient than those which are constructed from bilinear pairings.
文摘Objective:Diffuse Large B Cell Lymphoma(DLBCL)is a heterogeneous group of tumors with different biological and clinical characteristics that have diverse clinical outcomes and response to therapy.Stromal-1 signature of tumor microenvironment of DLBCL represents extracellular matrix deposition and histiocytic infiltrate,whereas stromal-2 represents angiogenesis that could affect tumor progression.Methods:The aim of the present study is to assess the significance of stromal-1 signature using SPARC-1 and stromal-2 signature using CD31 expression and then finally to construct biologic prognostic model(BPM)in 60 cases of DLBCL via immunohistochemistry.Results:Microvessel density(P<0.05)and SPARC percentage of expression(P<0.001)were higher in DLBCL,including germinal and nongerminal cases,compared with reactive follicular hyperplasia.High microvessel density was significantly associated with splenic involvement(P=0.008),high mitotic count(P=0.045),and presence of capsular invasion(P=0.035).Percentage of SPARC expression was significantly associated with splenic involvement(P=0.03).Constructing BPM showed that 42 cases(70%)were of low biologic score(0–1)and 18 cases(30%)were of high biologic score(2–3).Low BPM cases showed less probability for splenic involvement(P=0.04)and a higher rate of complete response to therapy compared with high score cases(P=0.08).Conclusions:The DLBCL microenvironment could modulate tumor progression behavior since angiogenesis and SPARC positive stromal cells promote dissemination by association with spleen involvement and capsular invasion.Biologic prognostic models,including modified BPM,which considered cell origin of DLBCL and stromal signature pathways,could determine DLBCL progression and response to therapy.
基金Supported by the National Natural Science Foundation of China （No. 60970111, 61133014, 60903189, 60903020）.
文摘Due to the compromise of the security of the underlying system or machine stonng the key, exposure of the private key can be a devastating attack on a cryptosystem. Key insulation is an important technique to protect private keys. To deal with the private （signing） key exposure problem in identity-based signature systems, we propose an identity-based threshold key-insulated signature （IBTKIS） scheme. It strengthens the security and flexibility of existing identity-based key-insulated signature schemes. Our scheme＇ s security is proven in the random oracle model and rests on the hardness of the computational Diffie-Helhnan problem in groups equipped with a pairing. To the best of our knowledge, it is the first IBTKIS scheme up to now.
