Large number Cipher

[xcoder]

print "######################################################"
global key
key = 5557878

num = 2654344211
print num :print
a = cipher(num)
print a   :print
b = decipher(a)
print b
print:print
print "End of Code"
End

function cipher(num)
for i = 0 to 31  'rounds of cipher
sum =  SHL(num,3) xor key
num = sum
print num
next
cipher = sum
end function

function decipher(num)
for i = 0 to 31  'rounds of cipher
sum2 = (num xor key)
sum3 = SHR(sum2,3)
num = sum3
print num
next
decipher = sum3
end function


function SHL(value,x)
SHL = value *2^x
end function


function SHR(value,x)
SHR = int(value/2^x)
end function