| 摘要 |
A method for distributing information includes distributing an item of encrypted information to a plurality of clients and distributing respective key-shares to the clients, such that each client will require a key-share that has been distributed to at least one other client in order to reconstruct a key for decrypting the encrypted information. Upon receiving from a first client a report that a second client requested and received a respective one of the key-shares from the first client, a record of a delivery of the item to the second client is made responsively to the report. Enables clients to download encrypted contents whilst on-line and purchase access to them whilst off-line simply by obtaining a key share from a nearby trustworthy client(s) using a local communication link such as BluetoothRTM. Both the trustworthy client(s) and purchasing client notify the content server of sharing of the key, thereby ensuring successful billing for the content even if the purchasing client has been hacked. May also be used for purchasing content whilst on-line. |
