Hash | Python Fiddle

def answer2(digest):
    result = []
    for each, num in enumerate(digest):
        print "Digest value %s, %s" %(each, num)
        if each == 0:
            previous_message = 0
        else:
            previous_message = result[each - 1]
            print previous_message 
        print 129 * num
        print (129 * num)  ^ previous_message
        result.append(((129 * num) ^ previous_message) % 256)
    return result

def answer(digest):
    result = []
    def find_message(num, previous_message):
        for i in range(256):
            
            if ((i * 129) ^ previous_message) % 256 == num:
                return (i)
                break
    
    for each, num in enumerate(digest):
        print "Digest value %s, %s" %(each, num)
        if each == 0:
            previous_message = 0
        else:
            previous_message = result[each - 1]
        result.append(find_message(num, previous_message))
    return result

digest = [0, 129, 5, 141, 25, 137, 61, 149, 113, 145, 53, 157, 233, 185, 109, 165] 
digest = [0, 129, 3, 129, 7, 129, 3, 129, 15, 129, 3, 129, 7, 129, 3, 129] # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
print answer(digest)

Browser Version Not Supported

Due to Python Fiddle's reliance on advanced JavaScript techniques, older browsers might have problems running it correctly. Please download the latest version of your favourite browser.
Chrome 10+ Firefox 4+ Safari 5+
IE 10+

Let me try anyway!

Python Fiddle

Python Cloud IDE