Group Key Agreement Protocol (GKAP) is a cryptographic mechanism where members of a group agree on a common key by sharing their blinded keys over a public channel. Sharing a key over a public channel is a security threat and expensive in terms of communication cost. In this paper, we proposed the GKAP based on tree and elliptic curve. For reducing the communication cost, we have used the divide-and-conquer mechanism with that group is divided into small subgroups and forming a tree-like structure. The modified Elliptic-Curve-Diffie–Hellman used for sharing the blinded key over a public network channel securely. This paper discussing different group key management operations are initialization, join, mass join, leave, mass-leave, merge with their communication cost are the number of rounds, unicast cost, broadcast cost, messages. This paper discussing the establishment of common keys not only for the group but also for the subgroups. Based on communication cost, we have compared the performance of proposed method with the existing approaches like Communication-Computation Efficient Group Key Algorithm (CCEGK), Tree-based group key agreement (TGDH), Ternary-tree based group key agreement protocol for dynamic group (TTGKAP), Group key generation tree protocol (GKGT), Ternary tree-based group key agreement protocol over elliptic curve for dynamic group (TTEGKAP), Efficient Group key agreement using hierarchical key tree (EGKAKT). From performance analysis, it is cleared that proposed approach performed better in most of the cases than the existing approaches. The proposed approach is safe against passive attack, collaborative attack, forward secrecy, backward secrecy, and man-in-the-middle attack.

组密钥协议协议（GKAP）是一种加密机制，其中组成员通过在公共通道上共享其盲密钥来就公共密钥达成一致。通过公共信道共享密钥是一种安全威胁，并且在通信成本方面很昂贵。在本文中，我们提出了基于树和椭圆曲线的GKAP。为了降低通信成本，我们使用了分而治之的机制，将这一组划分为一些小的子组并形成树状结构。修改后的Elliptic-Curve-Diffie-Hellman用于在公共网络通道上安全共享盲键。本文讨论了不同的组密钥管理操作，包括初始化，联接，批量联接，离开，批量离开，合并，其通信成本是轮数，单播成本，广播成本，消息。本文讨论了不仅为组而且为子组建立公共密钥的方法。基于通信成本，我们将建议方法的性能与现有方法（如通信计算有效组密钥算法（CCEGK），基于树的组密钥协议（TGDH），基于三叉树的动态组的组密钥协议）进行了比较（TTGKAP），组密钥生成树协议（GKGT），基于三元树的椭圆曲线上的动态组的分组密钥协议（TTEGKAP），使用分层密钥树的有效组密钥协议（EGKAKT）。从性能分析中可以清楚地看出，在大多数情况下，建议的方法都比现有方法表现更好。提议的方法可以安全地抵御被动攻击，协作攻击，前向保密，后向保密，