Abstract: Nodes determine a first measure of difficulty for a first branch of a split blockchain and a second measure of difficulty for a second branch of the split blockchain. The first measure of difficulty is based on a measure of block generation frequency of each node that mined for the split blockchain during a window that comprises blocks of the first branch. The second measure of difficulty is based on a measure of block generation frequency of each node that mined for the split blockchain during a window that comprises blocks of the second branch. One of the first branch and the second branch is identified as a legitimate branch based on a comparison of the first measure of difficulty and the second measure of difficulty.

Abstract: A record of authorization including user information is received and appended to a blockchain. The record of authorization authorizes access by a third-party application to the user information for an access duration. The user information is encrypted by a group key and access duration is based on a change to the group key. The group key comprises a public/private key pair, and the access duration is implemented by an authorization group of nodes having the group key. The group key corresponds to either a valid group key at or near the start of the access duration, that enables decryption of a message in the record of authorization that includes the user information, or an incompatible group key at or after the end of the access duration, that does not enable decryption of the message in the record of authorization that includes the user information.

Abstract: The current disclosure is directed towards providing methods and mechanisms enabling computationally efficient cross-chain messaging and message validation between subchains of a large-scale decentralized network. In one example, the current disclosure provides for determining if a message generated by a first subchain, received at a second subchain, represents a valid, consensually generated message of the first subchain, by comparing the received message with a public-key-share list of the first subchain stored in the second subchain. In one example, the current disclosure provides for a method comprising receiving a first message from a first subchain at a smart contract of a second subchain, wherein the smart contract of the second subchain comprises a public-key-share list of the first subchain, determining if the first message is valid based on the public-key-share list, and executing a transaction based on the first message responsive to the first message being determined valid.

Abstract: The current disclosure is directed towards efficiently generating random sequences on a large-scale peer-to-peer network. In one example, the disclosure provides for selecting a first node based on a block generation order, where the first node is selected to generate a current block, adding a first signature share of the first node to the current block, adding at least a second signature share from a previously selected node to the current block, generating a random sequence based on the first signature share and the second signature share, adding the random sequence to the current block, and publishing the current block to a blockchain maintained by a node pool. In this way, a random sequence may be generated on-chain, with linear messaging complexity, without relying on a single trusted party/apparatus, which may thereby decrease a probability of any single party controlling the random sequence produced.

Abstract: A processing node receives a finality proposal for a subject block within a blockchain. The finality proposal including an identifier of the subject block and one or more measures, wherein each of the one or more measures is based on the number of blocks within the blockchain that were mined by a respective node within the network of nodes other than the processing node. The processing node determines the subject block is a finalized block when a value based on the one or more measures satisfies a finality criterion. When the value fails to satisfy the finality criterion, the processing node transmits a subsequent finality proposal for the subject block. The subsequent finality proposal includes the identifier of the subject block, the one or more measures from the finality proposal, and an additional measure based on the number of blocks within the blockchain that were mined by the processing node.

Abstract: Nodes determine a first measure of difficulty for a first branch of a split blockchain and a second measure of difficulty for a second branch of the split blockchain. The first measure of difficulty is based on a measure of block generation frequency of each node that mined for the split blockchain during a window that comprises blocks of the first branch. The second measure of difficulty is based on a measure of block generation frequency of each node that mined for the split blockchain during a window that comprises blocks of the second branch. One of the first branch and the second branch is identified as a legitimate branch based on a comparison of the first measure of difficulty and the second measure of difficulty.

Abstract: A packet including a message intended for a smart contract associated with the second subchain and a node identifier is constructed at each of a plurality of nodes associated with the first subchain. The message constructed by the plurality of nodes are identical and may be a transaction request requesting the smart contract to execute on a blockchain. Each of the packets is sent to one or more nodes associated with the second subchain. The packets and messages received by one or more of a plurality of nodes associated with the second subchain are monitored and processed at the second subchain to determine if a consensus on request has been reached from the first subchain. If a consensus on request has been reached from the first subchain, the smart contract associated with the second subchain executes on the blockchain in accordance with the transaction request.