PERBANDINGAN SKEMA ENKRIPSI ANTARA METODE GABUNGAN CAT MAP – SDES DAN METODE GABUNGAN CAT MAP – PERMUTASI BLOK ACAK UNTUK CITRA DIGITAL (COMPARISON OF ENCRYPTION SCHEME BETWEEN COMBINATION METHOD OF CAT MAP – SDES AND COMBINATION METHOD OF CAT MAP – RANDO - Hadriyan Nurstiyo (Universitas Telkom, 2008)