New extension of data encryption standard over 128-bit key for digital images.

The strength of any block cipher depends on the key size, total number of rounds and the strength of confusion component against differential cryptanalysis. Data encryption standard (DES) as a block cipher has enjoyed a worldwide acceptance for more than three decades. It is a symmetric block cipher and considered to be very strong against all known attacks at that time. It uses 64-bit key size and block size, but the advancement in technology results in increasing the speed of the computers and thus makes DES not secure any more. The shorter key size is the weak area of DES. In this article, we have increased the block size as well as the key size from 64 to 128 bits. The internal structure of our proposed mechanism ultimately changed all other components of DES accordingly. By this improvement, our anticipated scheme is more secure due to its robust due to its confusion and diffusion components. The algorithm is applied on the plain text and on images. We have performed the standard benchmarks statistical analyses on our suggested encryption scheme in order to authenticate the anticipated mechanism. [ABSTRACT FROM AUTHOR]