I have noticed a slight change in the standard documentation of FIPS-202 and ISO/IEC 10118-3 documents for algorithm 5:rc(t) as below:
ISO/IEC 10118-3
Algorithm 5: rc(t)
Input: integer t
Output: bit rc(t)
Steps:
a)If t mod 255 = 0, return 1.
c)For i from 1 to t mod 255, let:
b) Let R = 10 000 000.
1) R = 0 || R;
2) R[0] = R[0] ⊕ R[8];
3) R[6] = R[6] ⊕ R[8];
4) R[3] = R[3] ⊕ R[8];
5) R[2] = R[2] ⊕ R[8];
6) R = Trunc8
FIPS-202
Algorithm 5: rc(t)
Input:
integer t.
Output:
bit rc(t).
Steps:
1. If t mod 255 = 0, return 1.
2. Let R = 10000000.
3. For i from 1 to t mod 255, let:
a. R = 0 || R;
b. R[0] = R[0] ⊕ R[8];
c. R[4] = R[4] ⊕ R[8];
d. R[5] = R[5] ⊕ R[8];
e. R[6] = R[6] ⊕ R[8];
f. R =Trunc8[R].
4. Return R[0]
Can anybody explain these difference or are the same?
