Abstract: In an access control method, a service access request of a service application is received. The service access request includes identity information of a user. An identity validation request is sent to a server. The identity validation request includes the identity information of the user. Challenge information is received from the server based on the identity information of the user in the identity validation request being determined to be valid. Signature information of the challenge information is generated based on the challenge information and a private key. The signature information is sent to the server. A signature valid message is received from the server based on the challenge information being obtained from the signature information with a public key associated with the identity information of the user. Based on the signature valid message, the service access request is sent to the server.

Abstract: This invention provides a general method for preparing a large oriented nanostructured mixed metal oxide (MMO) film comprising the steps of (a) preparing a highly (00l)-oriented LDH film, and (b) calcining the LDH film at a temperature of 300° C. to 1300° C. for 10 min to 36 h to obtain an oriented nanostructured MMO film. In the oriented MMO film, MMO nanoparticles are densely packed and form defect-free films which have high thermal stability. The major advantage of the present method is that it can be used for mass-production of large continuous oriented nanostructured MMO films without using any templates, lattice-matched single-crystalline substrates and/or expensive equipment, and the composition of the prepared MMO films can be readily adjusted by changing the composition of the LDHs fims as the precursor.