Many ready-made distributed software need to deliver group information and group memberships between group members. However, IP multi-broadcast can only provide unreliable disorderly information transmission services, and reliable information delivery provided by TCP but only Limited to two group members. Therefore, an IP multicast protocol that is a multi-point information transmission service that is a multi-point information transmission service for a group (arbitrary size) member is the topic of my attention. A group of groups on the Internet will more helpful, first assume that this group has the following features: 1) The group's size of any 2) Network transmission has a message of 3) groups asynchronous 4) Groups constantly occurring a variety of events such as group members to join or leave, groups between groups or split. Aiming at the above needs, a simple idea is: a) Assume that only one message sender in the group, ensuring the appearance of the message B) The receiving module of the group member adopts the request-retransmission mechanism to ensure the uncertainty of the network Although these transport mechanisms can basically meet some simple group communication needs, but if there are multiple messages in the group and the network environment is P2P? How does the message synchronize and how many multicast agreements are implemented? Group Key Agreement is a base part that implements secure communication between a group. It is based on distributed ideas. It is: 1) Groups of multiple members of the group participating in the key generation 2) Groups in groups are the parameters provided by each member and 3) groups jointly determined by the key generation algorithm. No members in the group cannot determine the key in advance. There are several popular group key negotiation and allocation methods, including CKD (BURMESTER-Desmedt), Str (Steer et al.), GDH (Group Diffie-Hellman) and TGDH (Tree -BASED Group Diffie-Hellman). Among them, GDH is based on ring ideas, TGDH based on Key Tree's idea, BD based on the idea of full broadcast. Three algorithms have their own advantages and disadvantages in the Group Key Negotiation Agreement. Some agreements are too ideal. It is not considered that there may be irreparableability between certain network nodes; some protocols are too complicated, it is difficult to implement . Take JOIN operation as an example, investigate the GDH and TGDH protocols in four aspects: (n is the number of group members) Key negotiation wheel number message number ring single to broadcast IP multicast GDH 4 N 3 n 1 2TGDH 2 3 Do not require 1BD 22N 2 without the need for 2N 2, it is understood that TGDH is based on Key Tree, in distributed networks (especially P2P networks), more of their robustness. However, how to determine the KEY tree, how to implement IP multicast in the Key tree, this is exactly the topic I want to study - group key negotiation in the P2P environment. My research is divided into two parts, the first layer is the transport layer protocol design, reference JGroup, intergroup, and jxta; the second layer is the group key negotiation protocol (mainly as the TGDH protocol).
