Cryptography using multinacci block matrices

In this paper, we propose public key cryptography using recursive block matrices involving generalized Fibonacci numbers over a finite field $\mathbb{Z}_{p}$. For this, we define multinacci block matrices, a kind of upper triangular matrix involving multinacci matrices at diagonal places and give some of its algebraic properties. Moreover, we set up a method for key element agreement at end users, which makes cryptography more efficient. The proposed cryptography comes with a large key space and its security relies on the Discrete Logarithm Problem (DLP).