# US 2020/0401561 A1 · Method, device, and computer program product for managing data object > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401561 A1 - Document ID: US20200401561A1 - Status: Published application - Kind: A1 - Application number: 16/722,548 - Filed: 2019-12-20 - Published: 2020-12-24 - Earliest claimed: 2019-06-21 - Assignees: EMC IP Holding Company LLC - Applicants: EMC IP Holding Company LLC - Inventors: Simon Yuting Zhang; Yizhou Zhou - Web page: https://patentgrep.com/patent/US20200401561A1 ## CPC - G06F 16/1844: {Management specifically adapted to replicated file systems} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - G06F 16/164: {File meta data generation} - G06F 16/1865: {Transactional file systems} - G06F 16/9024: {Graphs; Linked lists (G06F16/9027 takes precedence)} - H04L 9/0637: {Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - H04L 63/145: {the attack involving the propagation of malware through the network, e.g. viruses, trojans or worms} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present disclosure relates to a method, device and computer program product for managing a data object. In the method for managing a data object, a copy request for obtaining a copy of the data object is received from a requestor application system. At least one copy record associated with the data object is obtained from a group of copy records comprised in a copy blockchain associated with the data object. The number of copies of the data object is determined based on the at least one copy record. The copy request is handled based on the determined number of the copies. By means of immutable copy records comprised in the copy blockchain, the data object can be prevented from being illegally copied, and then higher security can be provided. Further, there is provided a device and computer program product for managing a data object. ## Claims ### Claim 1 A method for managing a data object, the method comprising: receiving from a requestor application system a copy request for obtaining a copy of the data object; obtaining at least one copy record associated with the data object from a group of copy records comprised in a copy blockchain associated with the data object; determining a number of copies of the data object based on the at least one copy record; and handling the copy request based on the determined number of the copies. ### Claim 2 (depends on 1) The method of claim 1, wherein handling the copy request based on the determined number of the copies comprises: executing the copy request in response to the determined number of the copies being lower than an allowed maximum number for the data object. ### Claim 3 (depends on 1) The method of claim 1, wherein the method is implemented at an owner application system where the data object is stored. ### Claim 4 (depends on 2) The method of claim 2, wherein executing the copy request comprises: notifying the requestor application system to submit to the copy blockchain a copy record associated with obtaining a copy of the data object; and transmitting the data object to the requestor application system in response to a copy record associated with a copy transaction being obtained from the copy blockchain. ### Claim 5 (depends on 4) The method of claim 4, further comprising: waiting a predetermined time interval in response to a copy record associated with the copy transaction not being obtained from the copy blockchain; and re-obtaining a copy record associated with the copy transaction from the copy blockchain. ### Claim 6 (depends on 4) The method of claim 4, wherein transmitting the data object to the requestor application system comprises: generating metadata comprising abstract information of the data object based on the data object; obtaining metadata associated with the data object from a metadata blockchain associated with the data object; and transmitting the data object to the requestor application system in response to determining the generated metadata and the obtained metadata match each other. ### Claim 7 (depends on 6) The method of claim 6, further comprising: in response to determining the generated metadata and the obtained metadata do not match each other, notifying the requestor application system that the data object has been modified. ### Claim 8 (depends on 7) The method of claim 7, further comprising: notifying a further owner application system, where a copy of the data object is stored, to transmit the data object to the requestor application system. ### Claim 9 (depends on 1) The method of claim 1, wherein a copy record of the at least one copy record comprises a copy transaction for obtaining a copy of the data object. ### Claim 10 (depends on 9) The method of claim 9, wherein a copy record of the at least one copy record is added to the copy blockchain in response to a historical copy transaction submitted by an application system. ### Claim 11 A device for managing a data object, comprising: at least one processing unit; at least one memory coupled to the at least one processing unit and having instructions stored thereon for being executed by the at least one processing unit, the instructions, when executed by the at least one processing unit, causing the device to perform operations, the operations comprising: receiving from a requestor application system a copy request for obtaining a copy of the data object; obtaining at least one copy record associated with the data object from a group of copy records comprised in a copy blockchain associated with the data object; determining a number of copies of the data object based on the at least one copy record; and handling the copy request based on the determined number of the copies. ### Claim 12 (depends on 11) The device of claim 11, wherein handling the copy request based on the determined number of the copies comprises: executing the copy request in response to the determined number of the copies being lower than an allowed maximum number for the data object. ### Claim 13 (depends on 11) The device of claim 11, wherein the device is implemented at an owner application system where the data object is stored. ### Claim 14 (depends on 12) The device of claim 12, wherein executing the copy request comprises: notifying the requestor application system to submit to the copy blockchain a copy record associated with obtaining a copy of the data object; and transmitting the data object to the requestor application system in response to a copy record associated with a copy transaction being obtained from the copy blockchain. ### Claim 15 (depends on 14) The device of claim 14, wherein the operations further comprise: waiting a predetermined time interval in response to a copy record associated with the copy transaction not being obtained from the copy blockchain; and re-obtaining a copy record associated with the copy transaction from the copy blockchain. ### Claim 16 (depends on 14) The device of claim 14, wherein transmitting the data object to the requestor application system comprises: generating metadata comprising abstract information of the data object based on the data object; obtaining metadata associated with the data object from a metadata blockchain associated with the data object; and transmitting the data object to the requestor application system in response to determining the generated metadata and the obtained metadata match each other. ### Claim 17 (depends on 16) The device of claim 16, wherein the operations further comprise: in response to determining the generated metadata and the obtained metadata do not match each other, notifying the requestor application system that the data object has been modified. ### Claim 18 (depends on 17) The device of claim 17, wherein the operations further comprise: notifying a further owner application system, where a copy of the data object is stored, to transmit the data object to the requestor application system. ### Claim 19 (depends on 11) The device of claim 11, wherein a copy record of the at least one copy record comprises a copy transaction for obtaining a copy of the data object. ### Claim 20 A computer program product, tangibly stored on a non-transient computer readable medium and comprising machine executable instructions, which when executed by a processor, cause the processor to perform operations, the operations comprising: receiving from a requestor application system a copy request for obtaining a copy of the data object; obtaining at least one copy record associated with the data object from a group of copy records comprising in a copy blockchain associated with the data object; determining a number of copies of the data object based on the at least one copy record; and handling the copy request based on the determined number of the copies.