Efektivitas Pesan Teks Dengan Cipher Substitusi, Vigenere Cipher, dan Cipher Transposisi

Abstract

Penelitian ini bertujuan untuk mengetahui efektivitas suatu keamanan pesan berbasis teks dengan metode kriptografi klasik seperti Substitusi, Vigenere, dan Transposisi. Dengan penerapan metode kriptografi, diharapkan mampu untuk meminimalisasi terjadinya penyadapan terhadap pesan teks. Ketiga metode tersebut, masing-masing akan di kombinasikan dan dibandingkan efektivitasnya berdasarkan ukuran file dan waktu proses. Terdapat tujuh kombinasi dari ketiga metode tersebut. Hasil pengujian efektivitas didapatkan hasil bahwa, ukuran file terbesar adalah kombinasi Substitusi, Vigenere, dan Transposisi yaitu 11 Kb, sedangkan yang terkecil adalah Substitusi dan juga Vigenere yaitu 5 Kb. Berdasarkan waktu proses terlama adalah Substitusi, Vigenere, dan Transposisi yaitu 1.54 detik, sedangkan yang tercepat adalah Substitusi yaitu 0.37 detik. Dari seluruh kombinasi yang ada, seluruhnya berhasil untuk proses enkripsi dan dekripsi guna mengembalikan cipher text menjadi plain text yang asli.

Rancang Bangun Aplikasi Mobile QR Code Untuk Validasi Pajak Reklame

“…A.A Ngr Narendra Dananjaya Ninggrat 1 , Ida Bagus Gede Manuaba 2 , Linawati 3 [Submission: 28-02-21, Accepted: 06-03-2021] Abstract-Advertisement is something media or equipment for delivering data, offering promotion, and presenting a product or service by using photos and interesting words, billboard tax recipients in the city of Denpasar have decreased every year even though the previous years the advertisement tax contributed the largest revenue in the city. The city of Denpasar, many who are not obedient in paying the advertisement tax, a breakthrough is needed to increase the return of advertisement tax revenue, where many tax users have not paid their obligations, the Denpasar city revenue agency has a duty to supervise the billboard tax in the city of Denpasar, so the design of mobile applications is created, Qr Code for billboard tax validation to oversee the billboard tax in the city of Denpasar, the system is designed to make it easier for Denpasar city revenue agency officers to validate the newly registered billboard tax because it is facilitated by the use of QR Code and it has been encrypted, use thealgorithm Speck so that security is guaranteed and in monitoring it has been integrated with google maps and using the djikstra method designed and created on the Android platform by utilizing web services.…”

“…Enkripsi proses atau mekanisme untuk mengubah sebuahpesan dari yang dapat dimengerti menjadi pesan yang tidak dapat dimengerti dengan sebuah kode/metode tertentu (1,3,4), Dengan adanya enkripsi suatu data akan diacak dengan sebuah kunci enkripsi untuk menjadi susunan karakter yang tidak bermakna bagi seseorang yang tidak memiliki kunci untuk proses dekripsinya [3].…”

Soft public key cipher

“…Based on NP-complete Knapsack cipher, the declared key encryption can be described in three methods, for the first and second method Use them not for authentication but for secrecy, whereas third method was used for authentication but not for secrecy, Shamir [3] studied the feasibility of construction, Merkle and Hellman (1978) propose a public-key system using Knapsack problem [4] by given A={a1,a2,….,an} positive integer and find the positive integer C (cipher text) by C=A.M or C= ,M={m1,m2,….mn} is represent the plaintext (Message) for example if A={10,8,17,20,15,9,6} and M={1,0,1,1,0,0,0} then C=10+17+20=47 The knapsack algorithm is one of the best algorithms to solve arbitrary instances of size n require O( ) time, in a simple Knapsack (super increasing) it solved in linear time algorithm snap (C,A): ("simple Knapsack algorithm") for i:= n down to 1 do begin if C ai then mi=1 else mi=0 C:=C-ai*mi end; if C=0 then snap:=M else " no solution exists " 2.2.1 Example given A=(1,3,5,10,22) and M=(1,1,0,1,0) then to encipher is : C=A*M=(1+3+10)=14 to decipher is : C= 1422 then m5=0 =14-22*0=14 C=1410 then m4=1 =14-10*1=4 C=45 then m3=0 =4-5*0=4…”

“…Merkle and Hellman convert it to a Trapdoor Knapsack [4], which hard to solve -choose A=(a 1 ,a 2 ,….a n ) , a i  -choose U2a n  -choose W so that gcd(U,W)=1 -compute W -1 = W (u)-1 mod U -compute E A =W*A mod U Where E A is public-key,A and W -1 are secrete to encipher is : C=E A *M To decipher : C'=w -1 *C mod U you have A and C' solve linearly form C'=A*M 2.3.1 Example: if A=(1,3,5,10) -U=20 -W=7 , gcd(7,20)=1 -then W -1 =W (U)-1 mod U =7 (7)-1 mod 7 =7 6-1 mod 7 =3 -E A =(7,1,15,10) (7*1 mod 20 , 7*3 mod 20 ,7*5 mod 20 ,7*10 mod 20) let the plaintext (M=13) then M=(1,1,0,1) to encipher is: C=E A *M=(7+1+10)=18 to decipher is: C'=C*W -1 mod U =3*18 mod 20 =14 C'=A*M=14= (1,3,5,10).M by snap(14,A*M) ,we get M=(1,1,0,1)…”

“…Moldtsov introduced in 1999 new mathematics to deal with the uncertainty concept of soft set Since this concept make the link between the set with the parameters of the set does not affect the current methods and be free of difficulties Since this theory has multiple applications has been previously proved by Moldtsov [1].Maji,p.k [2], from the theoretical side of soft sets, defined and studied many operations.Knapsack problem depending on the difficulty of solving that uses for either secrecy or authenticity, but not both the simple. Trapdoor Knapsack method depending on the Knapsack problem [3,4]. The signal to noise ratio (SNR) is an appropriate yardstick that uses in the characterization of the physical layer performance.…”