KEAMANAN DATA PADA POCKET PC DENGAN MENGGUNAKAN ALGORITMA GOST

In this research the writer constructed a data security application

program by using Gost algorithm and implemented it in Poket PC.

Algorithm Gost is a cipher block from former Soviet, an abbreviation from

“Gosudarstvennyi Standard” or governmental standard. The standard is of

number 28147-89, hence the method frequently called as Gost 28147-89. Gost

algorithm is a 64-bit (8-byte) cipher block. The algorithm iterates simple

encryption by 32 rounds with key length of 256 bits. To encrypt, firstly a 64-bit

plaintext is split into 32 bits of left side, L, and 32 bits of right side, R. The subkey

for rounds i is Ki. It is of the same operation as DES, that is, in one ith round. Gost

is an encryption method resembling DES (DES-like cipher) and created by Bruce

Schneier, directed to large processors (32 bits or more with equally large cache).

By applying Gost algorithm, the results of produced encryption tests

considerably varied, depending on the data size and the type of encryption file.

The processing time when both file encryption and description in Poket PC was

relatively long as compared to the encryption and description processes were in

PC. That was due to the limited memory (RAM) and processor of Poket PC.