Sending cross-chain authenticatable messages

A computer-implemented method for receiving a cross-chain authenticatable message, the method comprising:

• receiving from a relay, first data and first location information that have been sent by a first blockchain network to the relay for forwarding to a second blockchain network, wherein the first data comprises an authenticatable message, and the authenticatable message comprises at least (i) an identifier of the first blockchain network, (ii) an identifier of a first account of the first blockchain network that has sent the authenticatable message, (iii) message content of the authenticatable message, and (iv) an identifier of a recipient in the second blockchain network of the message content, and wherein the first location information indicates a location of the first data in the first blockchain network;
• obtaining, based on the identifier of the first blockchain network in the authenticatable message, second data related to the first blockchain network, wherein the second data has been previously received through the relay;
• verifying the authenticatable message based on the first data, the second data related to the first blockchain network, and the first location information;
• and
• after verification of the authenticatable message succeeds, providing the message content of the authenticatable message to the recipient in the second blockchain network, based on the identifier of the recipient in the authenticatable message.

A computer-implemented system, comprising:

• one or more computers;
• and
• one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform operations comprising:
• receiving from a relay, first data and first location information that have been sent by a first blockchain network to the relay for forwarding to a second blockchain network, wherein the first data comprises an authenticatable message, and the authenticatable message comprises at least (i) an identifier of the first blockchain network, (ii) an identifier of a first account of the first blockchain network that has sent the authenticatable message, (iii) message content of the authenticatable message, and (iv) an identifier of a recipient in the second blockchain network of the message content, and wherein the first location information indicates a location of the first data in the first blockchain network;
• obtaining, based on the identifier of the first blockchain network in the authenticatable message, second data related to the first blockchain network, wherein the second data has been previously received through the relay;
• verifying the authenticatable message based on the first data, the second data related to the first blockchain network, and the first location information;
• and
• after verification of the authenticatable message succeeds, providing the message content of the authenticatable message to the recipient in the second blockchain network, based on the identifier of the recipient in the authenticatable message.

A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations comprising:

• receiving from a relay, first data and first location information that have been sent by a first blockchain network to the relay for forwarding to a second blockchain network, wherein the first data comprises an authenticatable message, and the authenticatable message comprises at least (i) an identifier of the first blockchain network, (ii) an identifier of a first account of the first blockchain network that has sent the authenticatable message, (iii) message content of the authenticatable message, and (iv) an identifier of a recipient in the second blockchain network of the message content, and wherein the first location information indicates a location of the first data in the first blockchain network;
• obtaining, based on the identifier of the first blockchain network in the authenticatable message, second data related to the first blockchain network, wherein the second data has been previously received through the relay;
• verifying the authenticatable message based on the first data, the second data related to the first blockchain network, and the first location information;
• and
• after verification of the authenticatable message succeeds, providing the message content of the authenticatable message to the recipient in the second blockchain network, based on the identifier of the recipient in the authenticatable message.