# US 2018/0323965 A1 · Reduction in storage usage in blockchain

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- Number: US 2018/0323965 A1
- Document ID: US20180323965A1
- Status: Published application
- Kind: A1
- Application number: 15/802,052
- Filed: 2017-11-02
- Published: 2018-11-08
- Earliest claimed: 2017-05-03
- Assignees: International Business Machines Corporation
- Applicants: International Business Machines Corporation
- Inventors: Hiroki Yanagisawa
- Web page: https://patentgrep.com/patent/US20180323965A1

## CPC

- H04L 9/0637: {Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]}
- G06F 21/602: {Providing cryptographic facilities or services}
- G06F 21/64: Protecting data integrity, e.g. using checksums, certificates or signatures
- H04L 9/0643: {Hash functions, e.g. MD5, SHA, HMAC or f9 MAC}
- H04L 9/0891: {Revocation or update of secret information, e.g. encryption key update or rekeying}
- H04L 9/3236: {using cryptographic hash functions}
- H04L 9/3297: {involving time stamps, e.g. generation of time stamps}
- H04L 9/50: {using hash chains, e.g. blockchains or hash trees}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

Common data are maintained by a system including a plurality of node devices that each store a respective portion of a common data in a respective database, wherein a node device of the plurality of node devices stores a first portion of the common data, and receives a hash value of a second portion of the common data that is different from the first portion, in response to an update of the second portion of the common data.

## Claims

### Claim 1

A method, comprising:
storing a first portion of a common data in at least one node device from a plurality of node devices; and
receiving a hash value of a second portion of the common data that is different from the first portion, in response to an update of the second portion of the common data by the at least one node device, wherein each of the plurality of node devices stores at least a respective portion of the common data in a respective database.

### Claim 2 (depends on 1)

The method of claim 1, wherein the plurality of node devices collectively store the common data entirely.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
receiving a first transaction related to the first portion, by the at least one node device; and
updating the first portion of the common data based on the first transaction, by the at least one node device.

### Claim 4 (depends on 3)

The method of claim 3, further comprising:
calculating a hash value of the first portion, by the at least one node device; and
providing the hash value of the first portion to one or more other node devices from the plurality of node devices, by the at least one node device.

### Claim 5 (depends on 4)

The method of claim 4, further comprising storing a plurality of blocks, each block comprising the hash value of the first portion and the hash value of the second portion, by the at least one node device.

### Claim 6 (depends on 1)

The method of claim 1, further comprising requesting at least a part of the second portion of the common data to one or more other node devices from the plurality of node devices, by the at least one node device.

### Claim 7 (depends on 2)

The method of claim 2, wherein the at least one node device from the plurality of node devices stores the common data entirely.