ENCRYPTION SYSTEMS BASED ON CLOUD STORAGE AND METHOD THEREOF

摘要

A cloud storage-based encryption system for encrypting and storing a file in a cloud storage device includes: an encryption device for generating an encrypted file and a hashed file name of the file and generating a hashed keyword of the keyword set by the user; A cloud storage device for storing an encrypted file, generating a hash table using a hashed keyword, and generating a keyword table using the hashed file name; And can perform at least one of updating a keyword table, loading a stored file, searching a stored file, and deleting a stored file by using a hash table or a keyword table. Such a cloud storage based encryption system and method can support secure deletion, encrypted file system, and searchable encryption, which are essential elements for secure cloud storage. In addition, the cloud storage device stores only cryptographic data and hash data, and the master key, salt, or secret key for generating them may not be disclosed to the cloud storage device. In addition, a salt or secret key has a variable value according to a keyword or a file name, thereby constituting a security-safe system. Therefore, operations such as file storage, keyword update, file loading, retrieval, or deletion can be performed securely. In addition, all data except the master key is stored in the cloud storage device, so that the user can access the file stored in the cloud storage device regardless of which user terminal is used when the master key is stored. That is, the file of the cloud storage device can be easily accessed.