> Therefore, the data to be sent is 12345678 where 8 is the checksum. The problem in this kind of Checksum,

> is that when we interchange the numbers. say 7654321, then we compute:

>

> 7 + 6 + 5 + 4 + 3 + 2 + 1 = 28 where the modulo is also equal to

**8**>

> So whats the problem with this? The problem is that when we have a string say 'hello' the simple checksum is the

> same for 'olleh' or 'helol'.

>

> Because of that, there are new technologies and mathematical computation that arises and there comes the HASH.

> The same results will also arise for a longer string of lets say 100MB of File. A 1 or 4 byte of CRC is not enough

> for the accuracy of it... so far MD5 is the most reliable and secured HASH algorithm.

>

> -Mz

I see, a control sum is just a one algorithm (usually additive) to calculate a hash code. But by the way in the examples you posted we have exactly the same problem as with 'olleh' and 'helol':

www.foxite.com 20040801 = 0178387634

www.foxite.com 20040810 = 0178387634

www.foxite.com 20040802 = 0780136767

www.foxite.com 20040820 = 0780136767

www.foxite.com 20040812 = 0502775015

www.foxite.com 20040821 = 0502775015

www.foxite.com 20040803 = 0694851974

www.foxite.com 20040830 = 0694851974

Regards,

Sergey