Methods, systems, and apparatuses for optimal group key management for secure multicast communication

摘要

Apparatuses, systems, and methods for optimal group key (OGK) management that may achieve non-colluding and/or the storage-communication optimality are disclosed. In some embodiments, a group controller (GC) is responsible for key generation and distribution and the group data are encrypted by a group key. When joining the group, in some embodiments, each group member (GM) is assigned a unique n-bit ID and a set of secrets, in which each bit is one-to-one mapped to a unique secret. Whenever GMs are revoked from the group, in some embodiments, the GC will multicast an encrypted key-update message. Only the remaining GMs may be able to recover the message and update GK as well as their private keys. The disclosed OGK scheme can achieve storage-communication optimality with constant message size and immune to collusion attack and also may outperform existing group key management schemes in terms of communication and storage efficiency.

主权项

1. A method for group key management of group members in a multicast system, each of the group members having a unique ID, comprising:
determining a group master key and a group public parameter; processing a join request from a new group member, comprising:
assigning an available unique ID with a corresponding bit-assignment to the new group member;generating, with a processing device, a set of private keys for the new group member, the set of private keys based on the group master key and the bit-assignment corresponding to the available unique ID such that each private key of the set of private keys is mapped to a bit of the bit-assignment;multicasting a random group key to the group members; andcommunicating the random group key and the set of private keys to the new group member; and transmitting an encrypted message to a subset of the group members comprising:
determining a set of bit assignments for the subset of group members based on the unique IDs of the group members in the subset of group members;encrypting a message based on the master key, the group public parameter, and the set of bit assignments for the subset of group members; andmulticasting the encrypted message to the group members.