Data block modification

Abstract

A method of modifying a data block of a data structure comprising a plurality of linked data blocks comprising: receiving a selection of said data block comprising block data; creating modified block data; transmitting a request to a plurality of validator devices over a network, said request comprising a modification record and requesting permission to modify said data block in accordance with the modified block data; determining that consensus is reached by the plurality of validator devices that said data block can be modified in accordance with the modified block data; in response to said determining: modifying said data block in accordance with the modified block data; and adding a modification data block to the data structure, the modification data block comprising: the modification record and a cryptographic hash of a data block that precedes the modification data block after addition of the modification data block to the data structure.

What is claimed: 
     
         1 . A method of modifying a data block of a data structure comprising a plurality of linked data blocks, the method implemented on a computing device, and comprising:
 receiving a selection of said data block comprising block data;   creating modified block data based on the block data and user input received at the computing device;   transmitting a request to a plurality of validator computing devices over a communication network, said request comprising a modification record and requesting permission to modify said data block in accordance with the modified block data, wherein said modification record comprises (i) at least one data portion identifier of said block data, each of the at least one data portion identifier associated with a respective data portion of said data block modified in creating the modified block data; (ii) modification information; (iii) a cryptographic hash of said data block when comprising the block data; (iv) a cryptographic hash of said data block when comprising the modified block data; and (v) an integrity measure;   determining that consensus is reached by the plurality of validator computing devices that said data block can be modified in accordance with the modified block data;   in response to said determining:
 modifying said data block in accordance with the modified block data; and 
 adding a modification data block to the data structure comprising the plurality of linked data blocks, the modification data block comprising: the modification record and a cryptographic hash of a data block that precedes the modification data block after addition of the modification data block to the data structure. 
   
     
     
         2 . The method of  claim 1 , wherein the modification information comprises the modified block data. 
     
     
         3 . The method of  claim 1 , wherein the modification information comprises instructions on how to generate the modified block data. 
     
     
         4 . The method of  claim 1 , wherein the modification record additionally comprises a block identifier associated with said data block. 
     
     
         5 . The method of  claim 1 , wherein the modification record additionally comprises a reason specifying why the data block is being modified. 
     
     
         6 . The method of  claim 1 , wherein the modifying said data block comprises one or more of:
 redacting data in a data portion of said data block;   deleting data in a data portion of said data block;   replacing data in a data portion of said data block with replacement data; and   adding new data to a data portion of said data block.   
     
     
         7 . The method of  claim 1 , wherein said integrity measure comprises at least one digital signature. 
     
     
         8 . The method of  claim 1 , wherein said integrity measure comprises at least one Message Authentication Code. 
     
     
         9 . The method of  claim 1 , wherein said integrity measure comprises at least one cryptographic hash. 
     
     
         10 . The method of  claim 1 , wherein the modification data block additionally comprises the modified block data. 
     
     
         11 . The method of  claim 1 , wherein the data structure comprising the plurality of linked data blocks is stored in memory of the computing device. 
     
     
         12 . The method of  claim 1 , wherein the data structure is structured in accordance with a distributed ledger technology. 
     
     
         13 . The method of  claim 12 , wherein the distributed ledger technology is blockchain. 
     
     
         14 . A computer-readable storage medium comprising instructions which, when executed by a processor of a computing device cause the computing device to perform the method of  claim 1 . 
     
     
         15 . A computing device for modifying a data block of a data structure comprising a plurality of linked data blocks, wherein the data structure is stored in memory accessible to the computing device, and the computing device comprising a processor configured to:
 receive a selection of said data block comprising block data;   create modified block data based on the block data and user input received at the computing device;   transmit a request to a plurality of validator computing devices over a communication network, said request comprising a modification record and requesting permission to modify said data block in accordance with the modified block data, wherein said modification record comprises (i) at least one data portion identifier of said block data, each of the at least one data portion identifier associated with a respective data portion of said data block modified in creating the modified block data; (ii) modification information; (iii) a cryptographic hash of said data block when comprising the block data; (iv) a cryptographic hash of said data block when comprising the modified block data; and (v) an integrity measure;   determine that consensus is reached by the plurality of validator computing devices that said data block can be modified in accordance with the modified block data;   in response to said determination:
 modify said data block in accordance with the modified block data; and 
 add a modification data block to the data structure comprising the plurality of linked data blocks, the modification data block comprising: the modification record and a cryptographic hash of a data block that precedes the modification data block after addition of the modification data block to the data structure. 
   
     
     
         16 . A method of verifying a data structure comprising a plurality of linked data blocks, the method performed on a computing device, and comprising:
 for a first data block at a beginning of the data structure:
 computing a cryptographic hash of the first data block; 
 determining if the cryptographic hash of the first data block matches a cryptographic hash stored in a successor data block of the first data block, and if the cryptographic hash of the first data block does not match the cryptographic hash stored in the successor data block of the first data block, storing information associated with the first data block as an entry in a list stored in memory accessible by the computing device; 
   analysing each subsequent data block in the data structure after said first data block by:
 determining if said subsequent data block is a modification data block, 
 wherein if said subsequent data block is not a modification data block, the method comprising:
 computing a cryptographic hash of the subsequent data block; 
 determining if the cryptographic hash of the subsequent data block matches a cryptographic hash stored in a successor data block of the subsequent data block, and if the cryptographic hash of the subsequent data block does not match the cryptographic hash stored in the successor data block of the subsequent data block, storing information associated with the subsequent data block as an entry in said list; 
 
 wherein if said subsequent data block is a modification data block, the method comprising:
 verifying an integrity measure of the modification data block; 
 if said verifying the integrity measure of the modification data block is successful, determining that information in the modification data block matches information of a matching entry in said list, and in response, removing said matching entry from said list; 
 
   in response to completion of said analysing, successfully verifying the data structure based upon detecting that said list comprises no entries.   
     
     
         17 . The method of  claim 16 , wherein the method comprises determining that verifying the data structure has failed if said verifying the integrity measure of the modification data block is unsuccessful. 
     
     
         18 . The method of  claim 16 , wherein in response to completion of said analysing, the method comprises determining that verifying the data structure has failed upon detecting that said list comprises one or more entries. 
     
     
         19 . A computer-readable storage medium comprising instructions which, when executed by a processor of a computing device cause the computing device to perform the method of  claim 16 . 
     
     
         20 . A computing device for verifying a data structure comprising a plurality of linked data blocks, wherein the data structure is stored in memory accessible to the computing device, and the computing device comprising a processor configured to:
 for a first data block at a beginning of the data structure:
 compute a cryptographic hash of the first data block; 
 determine if the cryptographic hash of the first data block matches a cryptographic hash stored in a successor data block of the first data block, and if the cryptographic hash of the first data block does not match the cryptographic hash stored in the successor data block of the first data block, storing information associated with the first data block as an entry in a list stored in memory accessible by the computing device; 
   analyse each subsequent data block in the data structure after said first data block by:   determining if said subsequent data block is a modification data block,   wherein if said subsequent data block is not a modification data block, the processor configured to:
 compute a cryptographic hash of the subsequent data block; and 
 determine if the cryptographic hash of the subsequent data block matches a cryptographic hash stored in a successor data block of the subsequent data block, and if the cryptographic hash of the subsequent data block does not match the cryptographic hash stored in the successor data block of the subsequent data block, storing information associated with the subsequent data block as an entry in said list; 
   wherein if said subsequent data block is a modification data block, the processor is configured to:
 verify an integrity measure of the modification data block; 
 if said verification of the integrity measure of the modification data block is successful, determine that information in the modification data block matches information of a matching entry in said list, and in response, remove said matching entry from said list; 
   in response to completion of said analysis, successfully verify the data structure based upon detecting that said list comprises no entries.