  This paper proposes to put forward an innovative algorithm for symmetric key
block cipher named as "Triple Prime Symmetric Key Block Cipher with Variable
Key-Spaces (TPSKBCVK)" that employs triple prime integers as private key-spaces
of varying lengths to encrypt data files. Principles of modular arithmetic have
been elegantly used in the proposed idea of the cipher. Depending on
observations of the results of implementation of the proposed cipher on a set
of real data files of several types, all results are registered and analyzed.
The strength of the underlying design of the cipher and the liberty of using a
long key-space expectedly makes it reasonably non-susceptible against possible
cryptanalytic intrusions. As a future scope of the work, it is intended to
formulate and employ an improved scheme that will use a carrier media (image or
multimedia data file) for a secure transmission of the private keys.
