Abstract: The embodiments described herein comprise hardware and software improvements in blockchain-asset exchange technology, whereby one or more servers automatically, based on a set of predetermined rules, executes a mechanism allowing blockchain-asset exchange customers to place standing-limit or market orders for blockchain-based digital assets (e.g., cryptocurrencies) with a counter-party, but without counter-party risk. The counter-party will not receive the payment until the customer's exchange order has executed, and the customer has taken possession and ownership of the desired asset. The customer cannot reverse payment or otherwise rescind the payment from the counter-party once the customer receives the desired asset.

Abstract: A trusted blockchain oracle observes events extrinsic to a blockchain to yield an indication of the extrinsic event suitable for submission to a decentralized application on a blockchain. The trusted blockchain oracle signs the indications of the extrinsic events to yield a signed blockchain record. The trusted blockchain oracle publishes a feed of the signed blockchain records or otherwise distributes the signed blockchain records to potential users of the decentralized application at low computational cost. Users who wish to submit a signed blockchain record to the decentralized application may form and broadcast their own transactions including the signed blockchain record and bear the costs of confirming the transaction to the blockchain. The trusted blockchain oracle is thus relieved of the costs of confirming extrinsic events online and may provide a much larger amount of extrinsic event indications than would otherwise be possible.

Abstract: In some examples, a system or method of implementing a smart contract on a blockchain can involve receiving an indication of a portfolio of assets, an amount from a buyer to invest in the portfolio, a number of assets in the portfolio that is based on exchange rates and the amount to invest, and a confirmation from the buyer of the number of assets. The system or method can involve calculating a cost of the portfolio to yield a contract, receiving the amount and excess collateral from the buyer as a buyer acceptance of the contract, and an entity acceptance of the contract including an entity amount. The system or method can involve receiving, at the smart contract, a request from the buyer to close the contract, and settling the contract via the smart contract at a current value of the portfolio based on pricing data from a valuation entity.

Abstract: A trusted blockchain oracle observes events extrinsic to a blockchain to yield an indication of the extrinsic event suitable for submission to a decentralized application on a blockchain. The trusted blockchain oracle signs the indications of the extrinsic events to yield a signed blockchain record. The trusted blockchain oracle publishes a feed of the signed blockchain records or otherwise distributes the signed blockchain records to potential users of the decentralized application at low computational cost. Users who wish to submit a signed blockchain record to the decentralized application may form and broadcast their own transactions including the signed blockchain record and bear the costs of confirming the transaction to the blockchain. The trusted blockchain oracle is thus relieved of the costs of confirming extrinsic events online and may provide a much larger amount of extrinsic event indications than would otherwise be possible.