Cryptographic communication system and cryptographic communication method based on blockchain

Patent metadata

Field	Value
Publication number	US-11722316-B2
Application number	US-202016923521-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Dec 9, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A cryptographic communication system includes an electronic device configured to output a certificate and a transaction including a first hash value in which a certificate is hashed certificate, and a node configured to first determine whether the electronic device generated the transaction based on the transaction and the certificate, to second determine whether information included in the transaction and information included in the certificate coincide, and to third add a block to a distributed ledger depending on the result of the first determining and the second determining. The block includes the transaction, and the electronic device is configured to generate the certificate such that the certificate includes an ID of the electronic device and a public key of the electronic device.

First claim

What is claimed is:

1. A cryptographic communication system comprising:
an electronic device configured to output a certificate and a transaction including a public key, a signature, and a first hash value of the certificate; and
a node configured to first determine whether the electronic device generated the transaction based on the transaction and the certificate by comparing a second hash value generated by hashing of the certificate to a third hash value generated by decrypting the signature with the public key, to second determine whether information included in the transaction and information included in the certificate coincide by comparing the first hash value to the second hash value, and to third add a block to a distributed ledger depending on the result of the first determining and the second determining, wherein the block includes the transaction,
wherein the electronic device is configured to generate the certificate such that the certificate includes an ID of the electronic device and the public key of the electronic device,
wherein the electronic device is configured to execute a blockchain wallet and to generate the ID, the public key, and a private key corresponding to the public key, and
wherein, in response to the electronic device intending to register identity information on the distributed ledger, the electronic device is configured to generate a transaction such that the transaction includes a message including the ID, a registration command, the public key, and the first hash value, the signature being a result of an encryption of the message based on the private key.

2. The cryptographic communication system of claim 1 , wherein the electronic device is configured to generate the certificate such that each of an issuer field and a subject field of the certificate includes information about the ID.

3. The cryptographic communication system of claim 1 , wherein
the node is configured to determine that information included in the transaction and information included in the certificate coincide, in response to (a) the ID included in the transaction and an ID that the certificate coinciding, and (b) the public key included in the transaction and a public key that the certificate coinciding.

4. The cryptographic communication system of claim 1 , wherein, in response to the electronic device intending to revoke identity information registered at the distributed ledger after the identity information is registered at the distributed ledger, the electronic device is configured to generate a transaction such that the transaction includes a signature and a message including the ID, a revoke command, the public key, and the first hash value, the signature being a result of an encryption of the message based on the private key.

5. The cryptographic communication system of claim 1 , wherein, in response to the electronic device intending to update the identity information registered at the distributed ledger, the electronic device is configured to generate a new private key and a new public key corresponding to the new private key, to generate a new certificate including the new public key, and to generate a new transaction including (1) a first signature, (2) a second signature, and (3) a new message including (a) the ID, (b) an update command, (c) the public key, and (d) the new public key, and (e) a fourth hash value of a hashing of the new certificate, the first signature corresponding to an encryption of the message and the first hash value based on the private key, and the second signature corresponding to an encryption of the new message based on the new private key.

6. The cryptographic communication system of claim 5 , wherein the node is configured to determine that the electronic device generated the new transaction in response to (a) a hash value of a hashing of the certificate received from the electronic device and the fourth hash value being match with a value of a decryption of the first signature based on the public key included in the transaction, and (b) a fifth hash value of a hashing of the new certificate received from the electronic device being matched with a value of a decryption of the second signature based on the new public key included in the new transaction, and
the node is configured to determine that information included in the new transaction and information included in the new certificate coincide, in response to the ID included in the new transaction and an ID associated with the new certificate coincide, the new public key included in the new transaction and a new public key included in the new certificate coincide, and the fourth hash value and the fifth hash value coincide.

7. The cryptographic communication system of claim 1 , further comprising:
an extended electronic device having an extended public key and an extended private key,
wherein, in response to the electronic device intending to share the ID with the extended electronic device, the electronic device is configured to generate an extended certificate including the extended public key, and is configured to generate an extended transaction including (1) a first signature, (2) a second signature, and (3) an extended message including (a) the ID, (b) an extension command, (c) the public key, (d) the extended public key, and (e) a fourth hash value of a hashing of the extended certificate, the first signature corresponding to an encryption of the message and the first hash value based on the private key, and (f) the second signature corresponding to an encryption of the extended message based on the extended private key.

8. The cryptographic communication system of claim 7 , wherein the node is configured to determine that the electronic device generated the extended transaction, in response to (a) a hash value of a hashing of the certificate received from the electronic device and the third hash value matching with a value of a decryption of the first signature based on the public key included in the transaction, and (b) a fifth hash value of a hashing of the extended certificate received from the electronic device matching with a value of a decryption of the second signature based on the extended public key included in the extended transaction, and
the node is configured to determine that information included in the extended transaction and information included in the extended certificate coincide, in response to the ID included in the extended transaction and an ID included in the extended certificate coinciding, the extended public key included in the extended transaction and an extended public key included in the extended certificate coinciding, and the fourth hash value and the fifth hash value coinciding.

9. An electronic device of a cryptographic communication system, comprising:
an interface;
processing circuitry; and
a memory configured to store instructions executable by the processing circuitry,
wherein the instructions, when executed by the processing circuitry, cause the processing circuitry to,
generate a first certificate including an ID and a public key, the ID and the public key being associated with the electronic device,
generate a first transaction including a public key, a signature and a first hash value of a hashing of the first certificate,
output the first certificate and the first transaction to a distributed ledger through the interface,
obtain a second transaction including an identity of an external electronic device from the distributed ledger in response to a second certificate indicating the external electronic device received the identity of the external electronic device, and
verify the identity of the external electronic device based on the second certificate and the second transaction by

Assignees

• Samsung Electronics Co Ltd

Inventors

• Chu Younsung
• Huh Junho

Classifications

• H04L9/3263 Primary

  involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823) · CPC title

• H04L9/0643

  Hash functions, e.g. MD5, SHA, HMAC or f9 MAC · CPC title

• H04L9/3236

  using cryptographic hash functions · CPC title

• H04L9/3247

  involving digital signatures · CPC title

• H04L9/50

  using hash chains, e.g. blockchains or hash trees · CPC title