In this paper, we propose a modification probabilistic encryption algorithm by generating Basins (sub keys) dynamically. A probabilistic encryption produces more than one cipher text for the same plaintext. In probabilistic encryption, we use a secret shared key matrix. We multiply this key matrix with a matrix formed from ternary vector and then apply a sign function on the product, which generates a sequence. From this sequence we generate Basins using equality. In our paper we propose a mod with modulo base value to generate the Basins. As the base value changes, the number of Basins also changes. © 2012 Springer-Verlag.