Producing proof of receipt, existence and other data provenance evidence
A method of integrating a distributed ledger represented by a blockchain with a distributed storage network (DSN) begins by sending a proof of existence request to the DSN, the proof of existence request including an object name, an object version, a start time and an end time. The method continues by reading the object metadata for the sent object name. The method continues by checking a revision history from object metadata associated with the sent object name to ensure the object existed by the start time through the end time with no deletions and, if the object did not exist by the start time through the end time with no deletions, rejecting the proof of existence request and returning an error response. If the object did exist by the start time on through the end time with no deletions, the method continues by producing and returning an attestation comprising verification information related to the object.
1. A method for producing proof of existence of an object within a dispersed storage network (DSN), comprising the steps of:
sending, to the DSN, a proof of existence request for an object previously stored in the DSN, wherein the proof of existence request includes an object name, an object version, a start time and an end time;
reading object metadata of the object associated with the object name;
checking a revision history from the object metadata to ensure the object existed by the start time through the end time with no deletions;
if the object did not exist by the start time through the end time with no deletions, rejecting the proof of existence request and returning an error response; and
if the object did exist by the start time through the end time with no deletions, producing and returning an attestation comprising verification information related to the object; and
accepting the object, based on the verification information, to a blockchain.
2. The method of claim 1 , wherein the object version includes any object version over a time range of the start time to the end time that includes the object name.
3. The method of claim 1 , wherein the start time is considered a current time.
4. The method of claim 1 , wherein the end time is considered equal to the start time.
5. The method of claim 1 , wherein the attestation includes one or more of: the object name, the object version, an object hash, a time range, a distributed storage (DS) processing unit ID, a requester ID, a time the object was written, and the time the proof of existence request was processed.
6. The method of claim 5 , wherein the attestation includes a digital signature and a digital certificate containing a public key used to verify the digital signature.
7. The method of claim 1 further comprises including a proof of deletion, when the object has been deleted, that includes one or more of: the object name, an object version, a start time, and end time.
8. The method of claim 7 further comprises the DSN retaining, in DSN memory, object metadata when content of the object is deleted.
9. The method of claim 1 , wherein the object metadata retains an entire version history for the object, when each version is written, and when each version is deleted.
10. A computing device comprises:
an interface configured to interface and communicate with a communication system;
memory that stores operational instructions; and
processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to integrate a distributed ledger represented by a blockchain with a distributed storage network (DSN) by:
sending, to the DSN, a proof of existence request for an object previously stored in the DSN, wherein the proof of existence request includes an object name, an object version, a start time and an end time;
reading object metadata of the object associated with the object name;
checking a revision history from the object metadata to ensure the object existed by the start time through the end time with no deletions;
if the object did not exist by the start time through the end time with no deletions, rejecting the proof of existence request and returning an error response; and
if the object did exist by the start time through the end time with no deletions, producing and returning an attestation comprising verification information related to the object; and
accepting the object, based on the verification information, to the blockchain.
11. The computing device of claim 10 , wherein the attestation includes one or more of: the object name, the object version, an object hash, a time range, a distributed storage (DS) processing unit ID, a requester ID, a time the object was written, and the time the proof of existence request was processed.
12. The computing device of claim 10 , wherein the attestation includes a digital signature and a digital certificate containing a public key used to verify the digital signature.
13. The computing device of claim 10 further comprises including a proof of deletion, when the object has been deleted, that includes one or more of: the object name, an object version, a start time, and end time.
14. The computing device of claim 10 further comprises the DSN retaining, in DSN memory, object metadata when content of the object is deleted, wherein the object metadata includes an entire version history for the object, when each version is written, and when each version is deleted.