# An XOR alternative

# cat xor_alternative.py
import sys

# data contains hex chars (a-f + 0-9) and random chars
# Chars are not repeated
data = '2ubfLkR0vsJ#)=SQtXNcO6AYPT1U+ja7W*h9I-y4GeHzn5&BK;_@$U3dm8^%'

def obfuscate(s, step):
 out = ''
 ldata = len(data)
 ls = len(s)
 for i in s:
  h = hex(ord(i))[2:]
  for j in h:
   p = data.index(j)
   p2 = (p + step) % ldata
   out += data[p2]
 return out

def deobfuscate(s, step):
 out = ''
 ldata = len(data)
 ls = len(s)
 for i in range(0, ls, 2):
  h = ''
  for j in range(2):
   p = data.index(s[i + j])
   p2 = (p - step) % ldata
   h += data[p2]
  out += chr(int(h, 16))
 return out

action = sys.argv[1]
s = sys.argv[2]
step = int(sys.argv[3])

print 'String =', s
print 'Step =', step

if action == 'o':
 print 'Action = Obfuscate'
 print 'Result =', obfuscate(s, step)
elif action == 'd':
 print 'Action = Deobfuscate'
 print 'Result =', deobfuscate(s, step)

# python xor_alternative.py o SECRET 1234
String = SECRET
Step = 1234
Action = Obfuscate
Result = c+=c=+ch=cc=

# python xor_alternative.py d c+=c=+ch=cc= 1234
String = c+=c=+ch=cc=
Step = 1234
Action = Deobfuscate
Result = SECRET

Reference

https://isc.sans.edu/forums/diary/Obfuscating+without+XOR/22544/