Abstract: A system and method for providing cryptographic operation service in a virtualization environment. In the system, a configuration subsystem provides an interface for an administrator and a common user to input information about a virtual cryptographic device. A key file storage subsystem stores a key file and protects it with the protection password. A virtual machine operating subsystem obtains a corresponding key file from the storage subsystem according to the input of the configuration subsystem, creates a virtual device for a guest virtual machine, and finally operates the guest virtual machine to provide cryptographic computing service for the guest virtual machine. Thus the administrator/the common user can specify a key file and input a protection password for a guest virtual machine via the corresponding interface to facilitate the creation of a virtual cryptographic device, and can manage the virtual cryptographic device in a user-friendly and centralized manner.

Abstract: The present invention discloses a method and a system for checking revocation status of digital certificates in a virtualization environment.

Abstract: A system and method for providing cryptographic operation service in a virtualization environment. In the system, a configuration subsystem provides an interface for an administrator and a common user to input information about a virtual cryptographic device. A key file storage subsystem stores a key file and protects it with the protection password. A virtual machine operating subsystem obtains a corresponding key file from the storage subsystem according to the input of the configuration subsystem, creates a virtual device for a guest virtual machine, and finally operates the guest virtual machine to provide cryptographic computing service for the guest virtual machine. Thus the administrator/the common user can specify a key file and input a protection password for a guest virtual machine via the corresponding interface to facilitate the creation of a virtual cryptographic device, and can manage the virtual cryptographic device in a user-friendly and centralized manner.

Abstract: The present invention discloses a method and a system for checking revocation status of digital certificates in a virtualization environment.

Abstract: A PTC conductive composite material and the overcurrent protection device made of the material are disclosed. The PTC conductive composite material includes: (a) A matrix of crystalline polymer material at least, occupies 20%-70% of the volume fraction of the PTC conductive composite material, (b) One kind of conductive filler occupies 30%-80% of the volume fraction of the material. The solid solution conductive filler is uniformly dispersed in the polymer material, whose average particle size ranges from 0.1 ?m to 10 ?m, and the volume resistivity is no more than 300 ??·cm. The overcurrent protection device prepared by using the PTC conductive composite material as described above includes two metal foils, which are made into a sandwich, separated by a layer of the PTC conductive composite material. And the advantages of the overcurrent protection device of the invention are low resistance, good reproducibility of resistance and well PTC intensity.

Abstract: A PTC conductive composite material and the overcurrent protection device made of the material are disclosed. The PTC conductive composite material includes: (a) A matrix of crystalline polymer material at least, occupies 20%-70% of the volume fraction of the PTC conductive composite material, (b) One kind of conductive filler occupies 30%-80% of the volume fraction of the material. The solid solution conductive filler is uniformly dispersed in the polymer material, whose average particle size ranges from 0.1 ?m to 10 ?m, and the volume resistivity is no more than 300 ??·cm. The overcurrent protection device prepared by using the PTC conductive composite material as described above includes two metal foils, which are made into a sandwich, separated by a layer of the PTC conductive composite material. And the advantages of the overcurrent protection device of the invention are low resistance, good reproducibility of resistance and well PTC intensity.