Abstract: A validity management system for a digital file and a method for operating the same are provided. The system includes a file server that is connected with a file storage system and a blockchain for providing services of file preservation, verification and setting time validity. When an original file is received, an identification data is created and a hash value is calculated. The original file is uploaded to the file storage system that provides an original file address. The hash value, the identification data and the original file address are transmitted to the blockchain for creating a record. When any user requests for retrieving the original file, the original file is retrieved from the file storage system, and can be verified according to the record obtained from the blockchain. Afterwards, the user creates a copied file and decides accessibility of the copied file by setting time validity.

Abstract: The present invention provides a method of synchronous deletion for distributed storage system. According to the present invention, after a first host accesses one or more first datum, a first data list and a second data list will be created in a blockchain network corresponding to the modification of the data in the first host. Then the first data list and the second data list are used to update a second host. Accordingly, by taking advantages of the indestructibility of the blockchain technology, the existence of the first data list and the second data list will be maintained. Then the second data accessed by the second host will still be consistent even the first host has modified them. In addition, a hardware safety module can be further adopted to ensure the correctness of the execution file in the second host.

Abstract: The present invention provides a method of synchronous deletion for distributed storage system. According to the present invention, after a first host accesses one or more first datum, a first data list and a second data list will be created in a blockchain network corresponding to the modification of the data in the first host. Then the first data list and the second data list are used to update a second host. Accordingly, by taking advantages of the indestructibility of the blockchain technology, the existence of the first data list and the second data list will be maintained. Then the second data accessed by the second host will still be consistent even the first host has modified them. In addition, a hardware safety module can be further adopted to ensure the correctness of the execution file in the second host.