On Constructing Dynamic and Forward Secure Authenticated Group Key Agreement Scheme from Multikey Encapsulation...

Area of Science:

• Cryptography and Network Security
• Applied Mathematics
• Computer Science

Background:

• Group-authenticated key exchange (GAKE) protocols are crucial for secure group communication.
• Instantiating GAKE from multi-key encapsulation mechanisms (mKEM) offers single-round communication efficiency.
• Existing mKEM-based GAKE lacks forward secrecy and dynamic update capabilities.

Purpose of the Study:

• To enhance mKEM-based GAKE constructions with partial dynamicity.
• To introduce forward secrecy into the static GAKE framework.
• To analyze the implementation costs in elliptic curve cryptosystems.

Main Methods:

• Proposed an efficient solution to convert static mKEM-based GAKE into a partially dynamic scheme.
• Developed two variants of the generic construction to achieve forward secrecy.
• Compared mKEM instantiations based on elliptic curve scalar multiplication counts.

Main Results:

• Achieved a partially dynamic GAKE scheme from mKEM.
• Introduced two variants providing forward secrecy at the cost of an additional communication round.
• Quantified implementation costs by comparing elliptic curve scalar multiplications for different mKEM algorithms.

Conclusions:

• The mKEM-based GAKE approach can be efficiently extended for dynamic group environments.
• Forward secrecy can be incorporated, balancing security with communication overhead.
• The study provides a practical comparison for deploying secure and efficient GAKE protocols using elliptic curves.