Cryptography on elliptic curves over p-adic number fields

In this paper we introduce a cryptosystem based on the quotient groups of the group of rational points of an elliptic curve defined over p-adic number field. Some additional parameters are taken in this system, which have an advantage in performing point multiplication while keeping the security of ECC over finite fields. We give a method to select generators of the cryptographic groups, and give a way to represent the elements of the quotient groups with finitely bounded storage by establishing a bijection between these elements and their approximate coordinates. The addition formula under this representation is also presented.