Communication device and non-transitory computer-readable recording medium storing computer-readable instructions for communication device

Patent metadata

Field	Value
Publication number	US-12438852-B2
Application number	US-202318511997-A
Country	US
Kind code	B2
Filing date	Nov 16, 2023
Priority date	Nov 25, 2022
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

In a case where a first communication device obtains a first setting request not including first version information indicating a first version of an encrypted communication protocol but including second version information indicating a second version of the encrypted communication protocol, the first communication device may send first setting information to a second communication device, the first setting information including the second version information and second scheme information indicating a second encryption scheme but not including first scheme information indicating a first encryption scheme which is less secure than the second encryption scheme.

First claim

What is claimed is:

1. A first communication device, wherein
the first communication device supports a first version of an encrypted communication protocol and a second version of the encrypted communication protocol, the second version being newer than the first version,
the first version is capable of using a first encryption scheme,
the second version is capable of using the first encryption scheme and a second encryption scheme which is more secure than the first encryption scheme,
the first communication device comprises a controller, and
the controller is configured to:
obtain a setting request related to the encrypted communication protocol;
after the setting request has been obtained, send setting information according to the setting request to a second communication device; and
after the setting information has been sent to the second communication device, execute an encrypted communication with the second communication device by using a version and an encryption scheme that were determined by the second communication device based on the setting information,
wherein in a case where a first setting request not including first version information indicating the first version but including second version information indicating the second version is obtained, the controller is configured to send first setting information to the second communication device, the first setting information including the second version information and second scheme information indicating the second encryption scheme but not including first scheme information indicating the first encryption scheme, and
in a case where a second setting request including the first version information and the second version information is obtained, the controller is configured to send second setting information to the second communication device, the second setting information including the first version information, the second version information, the first scheme information, and the second scheme information.

2. The first communication device as in claim 1 , wherein
the first communication device further supports a third version of the encrypted communication protocol, the third version being newer than the second version,
the third version is incapable of using the first encryption scheme and the second encryption scheme and capable of using a third encryption scheme which is more secure than the second encryption scheme, and
in a case where a third setting request not including the first version information but including the second version information and third version information indicating the third version is obtained, the controller is configured to send third setting information to the second communication device, the third setting information including the second version information, the third version information indicating the third version, the second scheme information, and third scheme information indicating the third encryption scheme but not including the first scheme information.

3. The first communication device as in claim 1 , wherein
in a case where the second version is selected by a user on a first screen, the controller is configured to obtain the first setting request not including the first version information but including the second version information,
in a case where the first version and the second version are selected by the user on the first screen, the controller is configured to obtain the second setting request which includes the first version information and the second version information, and
an encryption key is not capable of being selected on the first screen.

4. The first communication device as in claim 3 , wherein
in a case where, on a second screen different from the first screen, the second version is selected by the user and one or more encryption schemes are selected by the user from among a plurality of encryption schemes that the second version is capable of using, the controller is configured to obtain a fourth setting request including the second version information and one or more scheme information indicating the one or more encryption schemes, the plurality of encryption schemes including the first encryption scheme and the second encryption scheme, and
in a case where the fourth setting request is obtained, the controller is configured to send fourth setting information to the second communication device, the fourth setting information including the second version information and the one or more scheme information.

5. The first communication device as in claim 1 , wherein
the encrypted communication protocol is a protocol according to Transport Layer Security (TLS).

6. A first communication device, wherein
the first communication device supports a first version of an encrypted communication protocol and a second version of the encrypted communication protocol, the second version being newer than the first version,
the first version is capable of using a first encryption scheme,
the second version is capable of using the first encryption scheme and a second encryption scheme which is more secure than the first encryption scheme,
the first communication device comprises a controller, and
the controller is configured to:
obtain a setting request related to the encrypted communication protocol;
after the setting request has been obtained, receive candidate information from a second communication device, the candidate information including version information indicating a version of the encrypted communication protocol which the second communication device is capable of using and scheme information indicating an encryption scheme which the second communication device is capable of using;
determine a target version and a target encryption scheme, the target version being a version of the encrypted communication protocol to be used in the encrypted communication with the second communication device, and the target encryption scheme being an encryption scheme to be used in the encrypted communication with the second communication device; and
execute the encrypted communication with the second communication device by using the target version and the target encryption scheme,
wherein in a case where a first setting request not including first version information indicating the first version but including second version information indicating the second version is obtained and first candidate information including the second version information and second scheme information indicating the second encryption scheme is received from the second communication device, the controller is configured to determine the second version as the target version and determine the second encryption scheme as the target encryption scheme,
in a case where the first setting request is obtained and second candidate information including the second version information and first scheme information indicating the first encryption scheme but not including the second scheme information is received from the second communication device, the first encryption scheme is not determined as the target encryption scheme,
in a case where a second setting request including the first version information and the second version information is obtained and the first candidate information is received from the second communication device, the controller is configured to determine the second version as the target version and determine the second encryption scheme as the target encryption scheme, and
in a case where the second setting request is obtained and the second candidate information is received from the second communication device, the controller is configured to determine the second version as the target version and determine the first encryption scheme as the target encryption scheme.

Assignees

• Brother Ind Ltd

Inventors

• Sasaki Hiroyuki

Classifications

• H04L9/16

  the keys or algorithms being changed during operation · CPC title

• H04L63/166

  at the transport layer · CPC title

• H04L63/205

  involving negotiation or determination of the one or more network security mechanisms to be used, e.g. by negotiation between the client and the server or between peers or by selection according to the capabilities of the entities involved (negotiation of communication capabilities H04L69/24) · CPC title

• H04L63/0428 Primary

  wherein the data content is protected, e.g. by encrypting or encapsulating the payload · CPC title