MD5 implementation notes
- by vaasu
While going through RFC1321, I came across the following paragraph:
This step uses a 64-element table T[1 ... 64] constructed from the
sine function. Let T[i] denote the i-th element of the table, which
is equal to the integer part of 4294967296 times abs(sin(i)), where i
is in radians. The elements of the table are given in the appendix.
From what I understood from paragraph, it means
T[i] = Integer_part(4294967296 times abs(sin(i)))
We know the following is true for all x:
0 <= sin(x) <= 1
Since i is an integer, abs(sin(i)) may very well be 0 for all values of i.
That means table will contain all zero values ( 4294967296 times 0 is 0).
In the implementation, this is not true. Why is this so?
Appendix contains just the raw values after calculation. It does not
show how it is derived from the sine function.
