Byzantine agreement in open networks

A computer-implemented system comprising:

• a hardware storage comprising a copy of decentralized database copy;
• a hardware processor configured to broadcast an indication to change a validation network for an open network from a current validation network to a next validation network, confirm based on one or more messages received from node computing devices of the open network an agreement to change to the validation network to the next validation network, run an instance of external validity multi-valued Byzantine agreement to determine a continuing sequence number to be used by the next validation network based on the sequence numbers of amendments applied to decentralized database copies stored on one or more of the node computing devices of the open network by determining that a proposed sequence number for a round of external validity multi-valued Byzantine agreement has not been accepted by the node computing devices participating external validity multi-valued Byzantine agreement, querying a random oracle to obtain a random value, concatenating the random value to each of two or more proposed sequence numbers, hashing the results of concatenating the value to each of two more proposed sequence numbers to generate hash values, and discarding the proposed sequence numbers whose hash values are not the lowest hash values, after determining the continuing sequence number, switch to listening to the next validation network as the validation network for the open network, and apply at least one amendment validated by the next validation network to the decentralized database copy in the storage, wherein the amendment comprises a sequence number that is higher than the continuing sequence number.

A system comprising:

• one or more computers and one or more storage devices storing instructions which are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:
• broadcasting, by a node computing device of an open network, an indication to change a validation network for the open network from a current validation network to a next validation network;
• confirming, based on one or more messages received from node computing devices of the open network, an agreement to change to the validation network to the next validation network;
• running, by the node computing device, an instance of external validity multi-valued Byzantine agreement to determine a continuing sequence number to be used by the next validation network based on the sequence numbers of amendments applied to decentralized database copies stored on one or more of the node computing devices of the open network by
• determining that a proposed sequence number for a round of external validity multi-valued Byzantine agreement has not been accepted by the node computing devices participating external validity multi-valued Byzantine agreement,
• querying a random oracle to obtain a random value,
• concatenating the random value to each of two or more proposed sequence numbers,
• hashing the results of concatenating the value to each of two more proposed sequence numbers to generate hash values, and
• discarding the proposed sequence numbers whose hash values are not the lowest hash values;
• after determining the continuing sequence number, switching, by the node computing device, to listening to the next validation network as the validation network for the open network;
• and
• applying, by the node computing device, at least one amendment validated by the next validation network to a decentralized database copy stored on the node computing device, wherein the amendment comprises a sequence number that is higher than the continuing sequence number.