Lattice-based cloud storage data safety auditing method supporting data proxy uploading

The invention belongs to the technical field of information safety, and in particular relates to a lattice-based cloud storage data safety auditing method supporting data proxy uploading. The auditing method provided by the invention helps a data owner authorize a proxy signature generating data to a proxy signer and upload the proxy signature to a cloud server, and also helps a credible auditor to audit completeness of the cloud storage data. The auditing method provided by the invention achieves construction of a random mask code based on an original image sampling algorithm on the lattice, so that the credible auditor can be effectively prevented from recovering original data block information of an original signer from a data file. The credible auditor only needs to compute a linear combination with limited a computation amount instead of computing bilinear pairings with higher cost and modular exponentiation during a cloud storage data completeness verification process, so that the auditing method is ver