چکیده (انگلیسی):

Hierarchical Access Control in group communication is an active area of research which is difficult to
achieve it. Its primary objective is to allow users of a higher authority group to access information or
resource held by lower group users and preventing the lower group users to access information held by
higher class users. Large collection of collaborative applications in organizations inherently has
hierarchical structures for functioning, where providing security by efficient group key management is
a big challenging issue. While preserving centralized methods for hierarchical access control, it is
difficult to achieve efficiency as a single membership change will result in lot of changes which are
difficult to maintain. So, using distributed key agreement techniques is more appropriate for this
scenario. This study explore on novel group key agreement approach, which combines both the
symmetric polynomial scheme and Tree Based Group elliptic Curve key exchange. Also, it yields a
secure protocol suite that is good in fault-tolerant and simple. The efficiency of SP-TGECDH is better
than many other schemes. Using TGECDH makes the scheme suitable small Low powered devices.