Virtual currency system

Abstract

Methods performed by a validation one or a sender one of a plurality of nodes implemented by computing devices in a network. The sender node sends, to the validation node, a request to transfer an amount of virtual currency from a sender account (associated with transaction receipts) to a recipient account. The request includes first copies of the receipts or references thereto. The validation node requests second copies of the receipts from at least two of the nodes, and receives the second copies from fewer than all of the nodes. The validation node determines whether the first copies have been tampered with by comparing the first and second copies to one another. When tampering has not occurred, at least one new receipt is generated indicating the amount has been transferred. Then, the at least one new receipt is forwarded to fewer than all of the nodes for storage.

1 .- 21 . (canceled) 
     
     
         22 . A computer-implemented method for use with a plurality of computing devices implementing a plurality of nodes of a ring-shaped overlay network, the method comprising:
 storing, by a storage one of the plurality of nodes, a transaction receipt for a transaction conducted between a sender node and a recipient node, the storage node comprising a publishing component;   publishing, by the publishing component, a message comprising a publication topic that comprises a recipient identifier associated with a recipient account of the recipient node;   subscribing, by the recipient node, to a recipient subscribed topic corresponding to the recipient identifier;   receiving, by the recipient node, the message that notifies the recipient node of completion of the transaction;   downloading, by the recipient node, a recipient copy of the transaction receipt;   storing, by the recipient node, the recipient copy of the transaction receipt in a recipient local storage associated with the recipient account; and   determining, by the recipient node, a recipient balance of the recipient account based at least in part on the recipient copy of the transaction receipt stored by the recipient local storage.   
     
     
         23 . The computer-implemented method of  claim 22 , wherein the recipient local storage is implemented by an embedded relational database. 
     
     
         24 . The computer-implemented method of  claim 22 , wherein the recipient identifier is a public key associated with the recipient node. 
     
     
         25 . The computer-implemented method of  claim 22 , further comprising:
 disconnecting, by the recipient node, from the ring-shaped overlay network after storing the recipient copy of the transaction receipt in the recipient local storage;   connecting, by the recipient node, to the ring-shaped overlay network after having disconnected therefrom;   subscribing, by the recipient node, to the recipient subscribed topic after connecting to the ring-shaped overlay network;   sending, by a portion of the plurality of nodes, recipient copies of all transaction receipts that are relevant to the recipient account to the recipient node; and   updating, by the recipient node, the recipient local storage based at least in part on the recipient copies.   
     
     
         26 . The computer-implemented method of  claim 22 , wherein the sender node implements a sender account and a sender local storage associated with the sender account, and the computer-implemented method further comprises:
 connecting, by the sender node, to the ring-shaped overlay network before conducting the transaction with the recipient node;   subscribing, by the sender node, to a sender subscribed topic after connecting to the ring-shaped overlay network, the sender subscribed topic being a sender identifier associated with the sender node;   sending, by a portion of the plurality of nodes, sender copies of all transaction receipts that are relevant to the sender account to the sender node;   updating, by the sender node, the sender local storage based at least in part on the sender copies; and   determining, by the sender node, whether a sender balance is sufficient for the transaction based on contents of the sender local storage before the transaction is conducted with the recipient node.   
     
     
         27 . The computer-implemented method of  claim 26 , wherein the sender identifier is a public key associated with the sender node. 
     
     
         28 . A computer-implemented method for use with a plurality of computing devices implementing a plurality of nodes of a ring-shaped overlay network, the method comprising:
 storing, by a storage one of the plurality of nodes, a transaction receipt sent to the storage node by a recipient one of the plurality of nodes, the storage node comprising a publishing component, the recipient node comprising a recipient account and a recipient local storage associated with the recipient account;   publishing, by the publishing component, a message to a first set of the plurality of nodes when the recipient node is disconnected from the ring-shaped overlay network, the message comprising a publication topic that comprises a recipient identifier associated with the recipient account; and   performing, by the recipient node, a synchronization process when the recipient node connects to the ring-shaped overlay network, the synchronization process comprising (a) sending a subscribe message to a second set of the plurality of nodes, the subscribe message comprising the recipient identifier and indicating to the second set that the recipient node wants to receive copies of any transaction receipts relevant to the recipient account, (b) receiving one or more recipient copies of the transaction receipt from at least a portion of the second set, and (c) updating the recipient local storage based at least in part on at least one of the one or more recipient copies of the transaction receipt; and   determining, by the recipient node, a recipient balance of the recipient account based on contents of the recipient local storage.   
     
     
         29 . The computer-implemented method of  claim 28 , wherein the recipient identifier is a public key associated with the recipient node. 
     
     
         30 . The computer-implemented method of  claim 28 , wherein the recipient local storage is implemented by an embedded relational database. 
     
     
         31 . A system comprising:
 a plurality of computing devices implementing a plurality of nodes that each configured to store transaction receipts, the plurality of nodes comprising a storage node and forming a distributed storage ring implemented as a ring-shaped overlay network;   a recipient computing device implementing a recipient node; and   a sender computing device implementing a sender node that does not form a part of the ring-shaped overlay network, the sender node comprising a sender account and a sender local storage associated with the sender account, the sender node being configured to connect to the distributed storage ring and send a sender subscribe message to the plurality of nodes after connecting to the distributed storage ring, the sender subscribe message comprising a sender identifier associated with the sender account and indicating to the plurality of nodes that the sender node wants to receive copies of any previous transaction receipts relevant to the sender account, at least a first portion of the plurality of nodes sending sender copies of relevant ones of the previous transaction receipts to the sender node, the sender node being configured to update the sender local storage based at least in part on the sender copies received from the first portion of the plurality of nodes, determine a sender balance of the sender account based on contents of the sender local storage, conduct a transaction with the recipient node when the sender node determines the sender balance is sufficient for the transaction, and disconnect from the ring-shaped overlay network, the recipient node being configured to route a new transaction receipt associated with the transaction to the storage node, the storage node forwarding storage copies of the new transaction receipt to others of the plurality of nodes for storage thereby such that the storage copies and the new transaction receipt are stored by fewer than all of the plurality of nodes.   
     
     
         32 . The system of  claim 31 , wherein the recipient node is configured to request, from the distributed storage ring, copies of any transaction receipts associated with the sender account to determine whether the sender balance of the sender account is sufficient to complete the transaction before the recipient node completes the transaction with the sender node. 
     
     
         33 . The system of  claim 31 , wherein the recipient node is one of the plurality of nodes, and
 the plurality of computing devices comprises the recipient computing device.   
     
     
         34 . The system of  claim 33 , wherein the storage node is configured to store the new transaction receipt and send a message to the recipient node,
 the message has a message topic that is a recipient identifier associated with the recipient node,   the recipient node comprises a recipient account and a recipient local storage associated with the recipient account,   the recipient node obtains a recipient copy of the new transaction receipt in response to the message, and updates the recipient local storage based at least in part on the recipient copy of the new transaction receipt, and   the recipient node is configured to determine a recipient balance of the recipient account based on contents of the recipient local storage.   
     
     
         35 . The system of  claim 31 , wherein the recipient computing device does not form a part of the ring-shaped overlay network, and
 the recipient node is configured to connect to the distributed storage ring, conduct the transaction with the sender node, route the new transaction receipt to the storage node, and disconnect from the ring-shaped overlay network.   
     
     
         36 . The system of  claim 35 , wherein the recipient node comprises a recipient account and a recipient local storage associated with the recipient account, the recipient node performs a synchronization process after the recipient node connects to the distributed storage ring, and the synchronization process comprises:
 (a) sending a recipient subscribe message to the plurality of nodes, the recipient subscribe message comprising a recipient identifier associated with the recipient account and indicating to the plurality of nodes that the recipient node wants to receive copies of any of the previous transaction receipts relevant to the recipient account;   (b) receiving recipient copies of those of the previous transaction receipts relevant to the recipient account from at least a second portion of the plurality of nodes; and   (c) updating the recipient local storage based at least in part on the recipient copies received from the second portion of the plurality of nodes.   
     
     
         37 . The system of  claim 31 , wherein the recipient local storage is implemented by an embedded relational database. 
     
     
         38 . The system of  claim 31 , wherein the recipient identifier is a public key associated with the recipient node. 
     
     
         39 . The system of  claim 31 , wherein the sender local storage is implemented by an embedded relational database. 
     
     
         40 . The system of  claim 31 , wherein the sender identifier is a public key associated with the sender node.