| 摘要 |
There is a server apparatus in which: an issuing unit issues data to devices; a distribution manager distributes the data to devices; a data manager manages data set as issued; a revocation manager detects, from the data set, data that satisfies a condition, and invalidates the detected data; and a filter manager updates and distribute to devices a filter having a predetermined bit length each time data is invalidated, by setting one of a first value and a second value to each of bits in the filter when a revoked data set is projected onto the filter; the data manager identifies data other than the invalidated data, having projection onto at least one of bits whose value has changed between before and after the update, and having the first value for all of bits projected onto the updated filter and reissues data to the device having the identified data. |
| 主权项 |
1. A server apparatus comprising:
a communication unit to connect to a wireless network in which a plurality of devices are connected; a data issuing unit to issue data to the devices in the wireless network, respectively; a data distribution manager to distribute the data issued by the data issuing unit to the devices, respectively; a data manager to manage a data set including the data issued by the data issuing unit; a revocation manager to detect, from the data set, data that satisfies a predetermined condition and invalidate the data detected; and a filter manager to: manage a revoked data set that is a set of pieces of data invalidated by the revocation manager; update a filter having a predetermined bit length each time the revocation manager invalidates data, by setting a first value to a bit projected when the revoked data set is projected onto the filter according to a definitive projection relation and setting a second value to a bit different from the projected bit in the filter; and distribute the filter after update to the devices in the network, wherein the data manager: identifies, from the data set, reissuance target data other than the data invalidated by the revocation manager, the reissuance target data having projection onto at least one of bits whose bit value has changed from the second value to the first value between before and after the update of the filter, and having the first value for all of bits projected when the reissuance target data is projected onto the filter after the update; and for the device having the reissuance target data, reissues data having the second value for at least one of bits projected when that data is projected onto the filter after the update, by means of the data issuing unit, and distributes a reissued data to the device. |
