var file,read,keypos,gmid,i,key

if !file_exists(argument0) then return (-1)

i=0
keypos=0
gmid=string(argument1)   
key=""
read=0
file=0

repeat (3)
{
      gmid=gmid + gmid
}
repeat(floor(string_length(string(gmid))*3 ))
{
      key=key + chr( ord(string_copy(gmid,i,2)) ^ (ord(string_char_at(argument1,keypos))-floor(i/3)))
      i+=1
      keypos+=1
      if keypos>string_length(argument1) then keypos=1
}
keypos=0

file=file_bin_open(argument0,2)
file_bin_seek(file,0)

repeat(file_bin_size(file))
{
      read=file_bin_read_b yte(file)
        
      file_bin_seek(file,file_bin_position(file)-1)
      
      file_bin_write_byte(file,read ^ ord(string_char_at(key,keypos)))
      keypos+=1
      if keypos>string_length(key) then keypos=1
}
file_bin_close(file)
return (1)