# US 2018/0323962 A1 · Reduction in storage usage in blockchain

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- Number: US 2018/0323962 A1
- Document ID: US20180323962A1
- Status: Published application
- Kind: A1
- Application number: 15/585,820
- Filed: 2017-05-03
- 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/US20180323962A1

## 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 system comprising:
a plurality of node devices that each store at least a respective portion of a common data in a respective database, wherein at least one node device from the plurality of node devices is configured to:
store a first portion of the common data; and
receive 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.

### Claim 2 (depends on 1)

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

### Claim 3 (depends on 2)

The system of claim 2, wherein the at least one node device is further configured to:
receive a first transaction related to the first portion; and
update the first portion of the common data based on the first transaction.

### Claim 4 (depends on 3)

The system of claim 3, wherein the at least one node device is further configured to:
calculate a hash value of the first portion; and
provide the hash value of the first portion to one or more other node devices from the plurality of node devices.

### Claim 5 (depends on 4)

The system of claim 4, wherein the at least one node device is further configured to store a plurality of blocks, each block comprising the hash value of the first portion and the hash value of the second portion.

### Claim 6 (depends on 1)

The system of claim 1, wherein the at least one node device is further configured to request 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.

### Claim 7 (depends on 2)

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

### Claim 8 (depends on 1)

The system of claim 1, wherein:
the plurality of node devices includes at least one new node device;
the at least one new node device is configured to store a third portion of the common data in response to joining the system; and
the third portion is the same as the first portion of the common data.

### Claim 9

A device comprising:
a storing section configured to store a first portion of a common data; and
a receiving section configured to receive 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.

### Claim 10 (depends on 9)

The device of claim 9, further comprising an updating section configured to update the first portion of the common data based on a first transaction, wherein the receiving section is further configured to receive the first transaction related to the first portion.

### Claim 11 (depends on 10)

The device of claim 10, further comprising:
a calculating section configured to calculate a hash value of the first portion; and
a providing section configured to provide the first portion to one or more other node devices from a plurality of node devices.

### Claim 12 (depends on 11)

The device of claim 11, wherein the storing section is further configured to store a plurality of blocks, each block comprising the hash value of the first portion and the hash value of the second portion.

### Claim at position 13

-19. (canceled)

### Claim 20

A computer program product having instructions embodied therewith, the instructions executable by a processor or programmable circuitry to cause the processor or programmable circuitry to perform operations of a method, the 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.