Abstract: A verifier device in one embodiment is configured to communicate over one or more networks with a client device and a server device. The verifier device participates in a three-party handshake protocol with the client device and the server device in which the verifier device and the client device obtain respective shares of a session key of a secure session with the server device. The verifier device receives from the client device a commitment relating to the secure session with the server device, and responsive to receipt of the commitment, releases to the client device additional information relating to the secure session that was not previously accessible to the client device. The verifier device verifies correctness of at least one characterization of data obtained by the client device from the server device as part of the secure session, based at least in part on the commitment and the additional information.

Abstract: Disclosed is a cryptocurrency system (“Arbitrum”) that supports smart contracts without the scalability and privacy limitations of previous systems such as Ethereum. Arbitrum, like Ethereum, allows parties to create smart contracts by using code to specify the behavior of a virtual machine (VM) that implements the contract's functionality. Arbitrum uses mechanism design to incentivize parties to agree off-chain on what a VM would do, so that the Arbitrum verifiers need only verify digital signatures to confirm that parties have agreed on a VM's behavior. In the event that the parties cannot reach unanimous agreement off-chain, Arbitrum still allows honest parties to advance the VM state on-chain. If a party tries to lie about a VM's behavior, the verifier (or miners) will identify and penalize the dishonest party by using a highly efficient challenge-based protocol that exploits features of the Arbitrum virtual machine architecture.