The present disclosure relates to a method and apparatus for recording mileage data of a vehicle on a blockchain. A method for recording mileage data of a vehicle on a blockchain is provided, including: providing a vehicle database and a mileage database, where the vehicle database is configured to store an identification number that uniquely identifies a vehicle, and the mileage database is configured to store mileage data about vehicle kilometers of travel (VKT); obtaining a vehicle identification number (VIN) from the vehicle database; obtaining the mileage data of the vehicle from the mileage database according to the VIN; and storing data related to the mileage data in the blockchain.

The present application relates to a data processing method and system of a distributed graph database. The present application solves the problem of how to improve the efficiency of adding, deleting, modifying and checking data in a graph database, realizes balanced storage and concurrent computing of distributed index, reduces network overhead caused by data operation, and improves the efficiency of data operation effectively.

A method includes executing an instruction to execute a query for a data block, the data block associated with a corresponding memory level of a logarithmic number of memory levels (l.sub.i) of memory, each memory level (l.sub.i) including physical memory (RAM.sub.i) residing on memory hardware of a distributed system. The method also includes retrieving a value associated with the data block from an oblivious hash table using a corresponding key, and extracting un-queried key value pairs from the oblivious hash table associated with un-queried data blocks after executing a threshold number of queries for data blocks. The method also includes a multi-array shuffle routine on the extracted key value pairs from the oblivious hash table to generate an output array containing the un-queried key value pairs.

An example operation may include one or more of identifying a new entry, receiving one or more new entry signatures to approve the new entry to, such that the one or more new entry signatures each include a signature of the new entry and hashes of previously signed entries for a common block, verifying the one or more new entry signatures for commit by performing a signature verification of the new entry, determining the common block has more than one entry with a hash signed by a same member, and responsive to the signature check being performed on the new entry and determining the common block has more than one entry with a hash signed by a same member, designating one or more previously received entries as verified for commit without performing a signature verification of the one or more previously received entries.

An attribute information setting section loads information indicating whether or not access to each of a plurality of files is allowed, into a memory. A readout request receiving section receives a readout request including a file path from a program. A hash value deriving section derives a hash value of a file path included in the readout request. A file confirming section confirms whether or not the derived hash value matches with one of hash values of the files included in software. A determining section refers to the information loaded into the memory by the attribute information setting section in a case in which matching of the hash values is confirmed, to thereby determine whether or not a process on the file which has been subjected to the readout request is executable.

Example implementations relate to generating a virtual co-parent key for a document information tree (DIT) including a plurality of child indexes each associated with a parent index. A virtual co-parent key for a first child index is generated. The first child index may be mapped to a child entry and may have a unique identification key including a child key and associated parent key. Generation of the co-parent key may include the computation of a co-parent seed key from the parent key or child key of the child index. Generation of the co-parent key may further include pre-pending the unique identification key with the computed co-parent seed key.

An example operation may include one or more of receiving, from a blockchain peer node, a sequence of blocks stored in a hash-linked chain of blocks on a distributed ledger, where each block in the sequence of blocks includes a reduced-step hash of block content from a previous block in the sequence, performing an approximate hash verification on the reduced-step hashes stored among the sequence of blocks, and determining whether the sequence of blocks has been tampered with based on the approximate hash verification on the reduced-step hashes.

The present disclosure relates to a method and apparatus for recording mileage data of a vehicle on a blockchain. A method for recording mileage data of a vehicle on a blockchain is provided, including: providing a vehicle database and a mileage database, where the vehicle database is configured to store an identification number that uniquely identifies a vehicle, and the mileage database is configured to store mileage data about vehicle kilometers of travel (VKT); obtaining a vehicle identification number (VIN) from the vehicle database; obtaining the mileage data of the vehicle from the mileage database according to the VIN; and storing data related to the mileage data in the blockchain.

A data deduplication process is performed in a storage system which includes storage nodes, and storage control nodes which can access data directly from each storage node. A first storage control node sends a message to a second storage control node to initiate a deduplication process with respect to a given data block and an original data block owned by the second storage control node. The second storage control node increments a reference counter associated with the original data block, and sends a message to the first storage control which includes metadata. The first storage control node uses the metadata to read the original data block from a given storage node, performs a data compare process to determine whether the given data block matches the original data block, and creates a reference to the original data block, if the given data block matches the original data block.

A blockchain system organized around digital identities and their accounts. Each account is treated as an independent blockchain and managed as a continuously growing Stateful Merkle Tree, while the blocks are treated as temporal synchronization points for all the chains in the system. Indexing of transactions in each block allows the system to operate at more than one synchronization level (frequency).