Common use of Group Key Agreement Clause in Contracts

Group Key Agreement. A comprehensive group key agreement solution must handle adjustments to group secrets subsequent to all membership change operations in the underlying group communication system. The following membership changes are considered: We distinguish among single and multiple member operations. We also distinguish between additive and subtractive member operations. Single member changes include member join or leave, and multiple member changes include group merge and group partition. 1) Network failure – this occurs when a network event causes disconnectivity within the group. Consequently, a group is split into fragments some of which are singletons while others (those that maintain mutual connectivity) are sub-groups. 2) Explicit (application-driven) partition – this occurs when the application decides to split the group into multiple components or simply exclude multiple members at once. 1) Network fault heal – this occurs when a network event causes previously disconnected network partitions to reconnect. Consequently, groups on all sides (and there might be more than two sides) of an erstwhile partition are merged into a single group. 2) Explicit (application-driven) merge – this occurs when the application decides to merge multiple pre-existing groups into a single group. (The case of simultaneous multiple- member addition is not covered.) At first glance, events such as network partitions and fault heals might appear infrequent and dealing with them might seem to be a purely academic exercise. In practice, however, such events are common owing to network misconfigurations and router failures. ▇▇▇▇▇ et al. present compelling arguments in support of these claims [22]. Hence, dealing with group partitions and merges is a crucial component of group key agreement. In addition to the aforementioned membership operations, periodic refreshes of group secrets are advisable so as to limit the amount of ciphertext generated with the same key and to recover from potential compromises of members’ contributions or prior session keys.

Group Key Agreement. A comprehensive group key agreement solution method must handle adjustments to group secrets subsequent subse- quent to all membership change operations in the underlying group communication system. The following membership Mem- bership changes are considered: We distinguish among can involve single and or multiple member operations. We also distinguish between additive and subtractive member operationsmembers. Single member changes include member join or leave, and multiple member changes include group merge and group partition. They can also be additive or subtractive in nature: join and merge are additive, while partition and leave are subtractive. 1) . Network failure – this occurs when a network event causes disconnectivity within the group. Consequently, a group is split into fragments some of which are singletons while others (those that maintain mutual connectivity) are sub-groups. 2) . Explicit (application-driven) partition – this occurs when the application decides to split the group into multiple components or simply exclude multiple members at once. 1) . Network fault heal – this occurs when a network event causes previously disconnected network partitions to reconnect. Consequently, groups on all sides (and there might be more than two sides) of an erstwhile partition are merged into a single group. 2) . Explicit (application-driven) merge – this occurs when the application decides to merge multiple pre-existing groups into a single group. (The case of simultaneous multiple- member addition is not covered.) At the first glance, events such as network partitions and fault heals might appear infrequent and dealing with them might seem to be a purely academic exercise. In practice, however, such events are common owing to network misconfigurations and router failures. ▇▇▇▇▇ et al. present compelling arguments in support of these claims [2221]. Hence, dealing with group partitions and merges is a crucial component of group key agreement. In addition to the aforementioned membership operations, periodic refreshes of group secrets are advisable so as to limit the amount of ciphertext generated with the same key and to recover from potential compromises of members’ contributions or prior session keys.