Abstract: In general, some embodiments described herein relate to using agile or dynamic addresses for multicasting that may be difficult or impossible for a malicious actor to predict. Such agile addresses may prevent a malicious actor from attacking a single static multicast address and may prevent the architecture of the multicast network from propagating the attack. Data sent to invalid (e.g., expired, revoked, and/or otherwise depreciated addresses) can be filtered out and dropped from the network. For example, a first group key associated with a first time period can be calculated based on a first shared secret and a second group key associated with a second time period can be calculated based on a second shared secret. At any given time at least one group key can be an accepted group key. When a multicast address includes a currently accepted group key, the data can be sent to a group.

Abstract: Some embodiments described herein relate to a method that can include receiving, at a first time, first data for routing to a group. The first data can be sent to the group via a first multicast address that is based, at least in part, on a first key associated with a first time period and derived from a first shared secret. At a second time, second data for routing to the group can be received. The second data can be sent to the group via a second multicast address that is different from the first multicast address. The second multicast address can be based, at least in part, on a second key associated with a second time period and derived from a second shared secret.

Abstract: An artificial disc (10) to replace a damaged spinal disc in a spinal column (16) includes a resilient core (60) having an upper surface (62) and a lower surface (64). An upper retaining member (20) has an outer surface (22) engageable with a first vertebra (12) of the spinal column (16) and an inner surface (24) affixed to the upper surface (62) of the resilient core (60). A lower retaining member (40) has an outer surface (42) engageable with a second vertebra (14) of the spinal column (16) and an inner surface (44) affixed to the lower surface (64) of the resilient core (60). One of the upper and lower retaining members (20, 40) has an opening (30, 50) extending through the outer and inner surfaces into which the resilient core (60) deflects upon relative movement of the upper and lower retaining members (20, 40).

Abstract: An apparatus for attaching a cranial flap (20) to a skull (10) comprises an attachment device (40) having relatively movable first and second members (42 and 44). The first member (40) has first and second surfaces (56 and 58) for engaging first and second kerf edges (24 and 26), respectively, of a kerf (22). The second member (44) has third and fourth surfaces (120 and 122) for engaging the first and second kerf edges (24 and 26), respectively. A shaft (46) connects the first and second members (42 and 44). The shaft (46) is attached to the second member (44) and extends through an opening (114) in the first member (42).