Classic Cipher : Vernam Cipher in Python (Encrypt)

The Vernam Cipher is based on the principle that each plaintext character from a message is 'mixed' with one character fr... thumbnail 1 summary

8 years ago

The Vernam Cipher is based on the principle that each plaintext character from a message is 'mixed' with one character from a key stream. If a truely random key stream is used, the result will be a truely 'random'ciphertext which bears no relation to the original plaintext (http://www.cryptomuseum.com/crypto/vernam.htm)

Vernam Cipher Decrypt : http://www.johanwahyudi.com/2016/11/classic-cipher-vernam-cipher-in-python_1.html

Code :

	#!/usr/bin/env python
	import random
	import string
	from operator import xor
	def vernam_enc(pesan):
	#perintah random string
	acak = ''.join([random.choice(string.ascii_letters) for i in xrange(len(pesan))])
	print "Teks random sebagai kunci : "+acak
	#fungsi convert ke desimal
	convdecimal = []
	for i in range(len(pesan)):
	convdecimal.append(str(ord(pesan[i])))
	decimal = ' '.join(convdecimal)
	#fungsi convert ke biner
	convbiner = []
	for i in range(len(convdecimal)):
	convbiner.append(str(bin(int(convdecimal[i]))[2:].zfill(8)))
	biner = ''.join(convbiner)
	print "hasil konversi ke biner karakter pesan : "
	print ' '.join(convbiner)

	#perintah convert key ke desimal
	convkeydecimal = []
	for i in range(len(acak)):
	convkeydecimal.append(str(ord(acak[i])))
	keydecimal = ' '.join(convkeydecimal)
	#fungsi conver key ke biner
	convkeybiner = []
	for i in range(len(convkeydecimal)):
	convkeybiner.append(str(bin(int(convkeydecimal[i]))))
	binerkey = ''.join(convkeybiner)
	print "Hasil KOnversi ke biner karakter kunci :"
	print ' '.join(convkeybiner)
	binerpesan =biner.replace("b","")
	print "biner pesan : \n"+binerpesan
	binerkey =binerkey.replace("b","")
	print "key biner : \n"+binerkey
	#fungsi xor variabel pesan dan key
	ciphertext = []
	for i in range(len(binerpesan)):
	ciphertext.append(xor(int(binerpesan[i]),int(binerkey[i])))
	cipherfix =''.join(map(str,ciphertext))
	splits=[cipherfix[x:x+8] for x in range(0,len(cipherfix),8)]
	print "Hasil XOR variabel pesan dan key : \n"+str(splits)
	#fungsi convert ke hexa
	hexa = []
	for i in range(len(splits)):
	hexa.append(hex(int(splits[i],2)))
	print "Hasil KOnversi hasil XOR ke hexa : \n"+str(hexa)
	#fungsi convert ke desimal
	dec = []
	for i in range(len(hexa)):
	dec.append(int(hexa[i], 16))
	print "Hasil Konversi ke Desimal : \n"+str(dec)
	#fungsi convert ke ascii text
	teks = []
	for i in range(len(dec)):
	teks.append(chr(dec[i]))
	save2file = ''.join(teks)
	print "Ciphertext : \n"+''.join(teks)
	#ciphertext di simpan ke file, supaya memudahkan pada waktu dekripsi,
	#karena pada waktu ciphertext di copas hasil conversi ke binernya beda
	outfile = open('ciphertext.txt','w')
	outfile.write(save2file)
	print "Ciphertext di simpan di ciphertext.txt"
	return save2file

	def main():
	print "Vernam Cipher"
	pesan = raw_input("Masukkan Pesan : ")
	print vernam_enc(pesan)
	if __name__ == '__main__':
	main()