  Security has become one of the major issue in mobile services. In the
development of recent mobile devices like Software Defined Radio (SDR) secure
method of software downloading is found necessary for reconfiguration. Hash
functions are the important security primitives used for authentication and
data integrity. In this paper, VLSI architecture for implementation of
integrity unit in SDR is proposed. The proposed architecture is reconfigurable
in the sense it operates in two different modes: SHA-192 and MD-5.Due to
applied design technique the proposed architecture achieves multi-mode
operation, which keeps the allocated area resource at minimized level. The
proposed architecture also achieves highspeed performance with pipelined
designed structure. Comparison with related hash function implementation have
been done in terms of operating frequency, allocated-area and area-delay
product. The proposed Integrity Unity can be integrated in security systems for
implementation of network for wireless protocol, with special needs of
integrity in data transmission.
