Encode / Decode String

[kevin]

   These functions are an encode and simple decoder.   The method used is we encode the source string by stepping through the input string character by character.   For each character we mult it by our key value, then output this value as a string following by a delimiter character which is the minus character in this example.       Next we step through this numeric data and replace various combinations with a-z.     

   The RestoreJunk does the same thing but in reverse to get back to the original string. 

PlayBASIC Code: [Select]

   openscreen  1200,500,32,1

   s$="..Hello World.."
   
   
   print "Original String:"+s$
   
   Key= 42287
   Encoded$=MakeJunk(s$,Key)

   print "Encoded String:"+Encoded$
   
    Result$=RestoreJunk(Encoded$,key)

   print ""
   
   print "Decoded String:"+Result$
   
   if s$=Result$
      print "Match"
   else
      print "They Dont match"   
   endif   


   
   Sync
   waitkey
   
   
   
Function MakeJunk(s$,key)

      // Convert to numbers   
      For lp =1 to Len(s$)
            ThisCHR=mid(s$,lp)
            ThisCHR=ThisCHR * Key   
            result$+=str$(ThisCHR)+"-"         
      next

      #print result$   

      // Convert Numbers to letters 
      for lp=asc("z") to asc("a") step -1
            ThisCHR = lp-asc("a")
            result$ = replace$(Result$,str$(ThisCHR),chr$(lp))
      next

   
EndFunction result$   
   

Function RestoreJunk(s$,key)
   
      // Convert Numbers to letters 
      for lp=asc("z") to asc("a") step -1
            ThisCHR = lp-asc("a")
            s$ = replace$(s$,chr$(lp),str$(ThisCHR) )
      next

      print s$

      Dim Numbers(1000)
      
      Count=SplitToArray(s$,"-",Numbers())
      
      for lp =0 to Count-1
         Result$+=chr$(Numbers(lp) / Key)
      next      
   
EndFunction result$