Abstract: A method for facilitating cryptocurrency transactions is disclosed. The method includes receiving, by a hub computer, a first user account identifier from a first service provider computer in communication with a first user device and a first blockchain network. The first service provider computer transfers an amount of digital currency to a first smart contract on the first blockchain network. The hub computer also receives a second user account identifier from a second service provider computer in communication with a second user device and a second blockchain network containing a second smart contract. The hub computer receives a first amount of a first digital currency from the first service provider computer, and then transfers a second amount of a second digital currency to the second service provider computer.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: A system and method is disclosed. The method comprises a client device receiving a verification request comprising an interaction identifier. The client device can then query a full node for a random sampling of block headers from the full node. The client device can receive the random sampling of block headers from the full node, and verify the random sampling of block headers. The client device can then determine that the blockchain maintained by the full node is valid after verifying the random sampling of block headers.

Abstract: A method includes broadcasting, by a node computer, a propose message comprising a new block for a blockchain to a plurality of node computers in a network shard. The node computer can receive at least one vote message from the plurality of node computers, the at least one vote message indicating verification of the new block. The node computer can, after a predetermined amount of time, receive a plurality of pre-commit messages comprising at least the new block and a block certificate created based on the at least one vote message. If the number of received pre-commit messages of the plurality of pre-commit messages is greater than a quorum value associated with the network shard, the node computer can commit the new block to the blockchain.

Abstract: Disclosed are systems and techniques for wireless communications. For instance, a wireless device may receive a signal from a first wireless network while the wireless device is in an idle mode; determine, from the received signal, a signal to noise ratio (SNR) and a doppler shift; retrieve stored network capability information; and estimate, based on the SNR, the doppler shift, and the stored network capability information, a throughput of the first wireless network.

Abstract: A node in a plurality of nodes can perform an identity set generation process. The node can then determine a leader node. The node may diffuse an identity set from each node of the plurality of nodes to the plurality of nodes. The node can then determine a majority set including identities occurring in at least one half of the identify sets, wherein the leader node diffuses the majority set of the leader node to the plurality of nodes. The node can verify the majority set of the leader node. The node may then update the identity set based on the majority set of the leader node.

Abstract: Blockchain-based, smart contract platforms have great promise to remove trust and add transparency to distributed applications. However, this benefit often comes at the cost of greatly reduced privacy. Techniques for implementing a privacy-preserving smart contract is described. The system can keep accounts private while not losing functionality and with only a limited performance overhead. This is achieved by building a confidential and anonymous token on top of a cryptocurrency. Multiple complex applications can also be built using the smart contract system.

Abstract: Methods, systems, and devices for wireless communications are described. A method of wireless communication at a user equipment (UE) is described that may include receiving a data packet transmission over a wireless channel from a base station. The method may further include determining a set of intrinsic log likelihood ratios (LLRs) based at least in part on the data packet transmission and determining an accumulated capacity for the wireless channel based at least in part on the set of intrinsic LLRs. The method may also include determining a channel quality indicator index or a transmission rank for the wireless channel based at least in part on the accumulated capacity and transmitting a feedback message that indicates the channel quality indicator index or the transmission rank for the wireless channel to the base station.

Abstract: A method includes broadcasting, by a node computer, a propose message comprising a new block for a blockchain to a plurality of node computers in a network shard. The node computer can receive at least one vote message from the plurality of node computers, the at least one vote message indicating verification of the new block. The node computer can, after a predetermined amount of time, receive a plurality of pre-commit messages comprising at least the new block and a block certificate created based on the at least one vote message. If the number of received pre-commit messages of the plurality of pre-commit messages is greater than a quorum value associated with the network shard, the node computer can commit the new block to the blockchain.

Abstract: A method includes a first device receiving, from a second device, an interaction request message comprising an amount and a second device certificate. The first device can verify the second device certificate using a server computer public key corresponding to a server computer private key. A trusted application in a secure element of the first device can determine whether or not the amount is less than an offline amount stored in the secure element. If the amount is less than the offline amount, the trusted application can determine an updated offline amount based on the amount. The trusted application can generate an interaction response message comprising the amount and a trusted application certificate. The first device can then provide the interaction response message to the second device.

Abstract: The method comprises a client device receiving a verification request comprising an interaction identifier. The client device can compare samplings of block headers received from two or more full nodes. The client device can then, based on the comparing, verify at least one block header of the samplings of block headers. The client device can determine that a blockchain maintained by at least one of the two or more full nodes is valid in response to verifying the at least one block header of the samplings of block headers.

Abstract: Methods and systems for generating a security policy at a gateway are disclosed. A server computer and a gateway can perform a protocol in order to train a security model at a gateway, such that it can detect attack packets and prevent those attack packets from reaching the server computer via the gateway. In a learning phase, the server computer can provide training packets and test packets to the gateway. The gateway can use the training packets to train a security model, and the gateway can classify the test packets using the security model in order to test its accuracy. When the server computer is satisfied with the accuracy of the security policy, the server computer can transmit an acceptance of the security policy to the gateway, which can subsequently deploy the model in order to detect and filter attack packets.

Abstract: A method is disclosed. The method includes: a) receiving node identifiers from nodes of a plurality of nodes in a computer network; b) determining a plurality of node committees in a sampler graph comprising a plurality of nodes, wherein the node is present in a node committee in the plurality of node committees; c) and i) generating a random string; ii) performing a proof of work process using the random string and a hash function; iii) if the proof of work process yields a solution that is acceptable, then broadcasting the solution to all other nodes in the plurality of nodes, wherein the other nodes verify the solution; and iv) if the other nodes verify the solution, the node is elected to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and d) repeating steps b) and c) until a leader committee is determined.

Abstract: Methods, systems, and devices for wireless communications are described. A method of wireless communication at a user equipment (UE) is described that may include receiving a data packet transmission over a wireless channel from a base station. The method may further include determining a set of intrinsic log likelihood ratios (LLRs) based at least in part on the data packet transmission and determining an accumulated capacity for the wireless channel based at least in part on the set of intrinsic LLRs. The method may also include determining a channel quality indicator index or a transmission rank for the wireless channel based at least in part on the accumulated capacity and transmitting a feedback message that indicates the channel quality indicator index or the transmission rank for the wireless channel to the base station.

Abstract: A method is disclosed. A node in a plurality of nodes can perform an identity set generation process. The node can then determine a leader node. The node may diffuse an identity set from each node of the plurality of nodes to the plurality of nodes. The node can then determine a majority set including identities occurring in at least one half of the identity sets, wherein the leader node diffuses the majority set of the leader node to the plurality of nodes. The node can verify the majority set of the leader node. The node may then update the identity set based on the majority set of the leader node.

Abstract: Systems and methods for transferring value. A method includes posting, by a user device to a blockchain, a deposit transaction comprising a deposit value and conditions and updating, by the user device, a state according to a transaction amount. The method also includes transmitting, by the user device, a state update of the state to a server computer and responsive to transmitting the state update, and receiving, by the user device, a payment complete message comprising a tuple from the server computer. The method also includes verifying, by the user device, the conditions and processing, by the user device, a server deposit transaction on the blockchain in response to verifying.

Abstract: A method includes: a) receiving node identifiers from nodes of a plurality of nodes in a computer network; b) determining a plurality of node committees in a sampler graph comprising a plurality of nodes, wherein the node is present in a node committee in the plurality of node committees; c) and i) generating a random string; ii) performing a proof of work process using the random string and a hash function; iii) if the proof of work process yields a solution that is acceptable, then broadcasting the solution to all other nodes in the plurality of nodes, wherein the other nodes verify the solution; and iv) if the other nodes verify the solution, the node is elected to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and d) repeating steps b) and c) until a leader committee is determined.

Abstract: Methods, systems, and devices for wireless communications are described. A method of wireless communication at a user equipment (UE) is described that may include receiving a data packet transmission over a wireless channel from a base station. The method may further include determining a set of intrinsic log likelihood ratios (LLRs) based at least in part on the data packet transmission and determining an accumulated capacity for the wireless channel based at least in part on the set of intrinsic LLRs. The method may also include determining a channel quality indicator index or a transmission rank for the wireless channel based at least in part on the accumulated capacity and transmitting a feedback message that indicates the channel quality indicator index or the transmission rank for the wireless channel to the base station.

Abstract: Systems and methods for transferring value. A method includes posting, by a user device to a blockchain, a deposit transaction comprising a deposit value and conditions and updating, by the user device, a state according to a transaction amount. The method also includes transmitting, by the user device, a state update of the state to a server computer and responsive to transmitting the state update, and receiving, by the user device, a payment complete message comprising a tuple from the server computer. The method also includes verifying, by the user device, the conditions and processing, by the user device, a server deposit transaction on the blockchain in response to verifying.

Abstract: A method includes a first user device generating an interaction message. The interaction message includes an amount, an expiry time, and a condition. The first user device provides the interaction message to a second user device. The second user device creates a witness that satisfies the condition and provides the witness to the first user device. The first user device receives the witness from the second user device. The first user device verifies that the witness satisfies the condition. If the witness satisfies the condition and is received prior to the expiry time, the first user device signs the witness using a first user device private key to obtain a signed witness. The first user device provides the signed witness to the second user device. The second user device verifies a signature of the signed witness and proceeds with obtaining the amount.