Is there an error in the Solutions for Homework 3 that Dr. Guo posted? 

For #4a where you encrypt 'phone', I agree with the solutions that:

p = 15   (P1 = 15)

h = 7     (P2 = 7)

o = 14   (P3 = 14)

n = 13   (P4 = 13)

e = 4     (P5 = 4)

HOWEVER, when we're calculating the C2 for each of them, the solution says that:

for P2, which is 7,

C2 = (P2 * e2^r) mod p = (2*1117^103) mod 1327 = 7* 437 mod 1327 = 405  (should't it be 7, not 2?)

for P3, which is 14, 

C2 = (P3 * e2^r) mod p = (18*1117^103) mod 1327 = 14* 437 mod 1327 = 810  (shouldn't it be 14, not 18?)

(same for P4, and for P5)

This are mistakes in the solutions, right? Would love some confirmation. Thanks!

Thanks! I'm 98% sure they are typos too. 

Are you talking about #1a S-AES? There are way too many steps to list on this forum, but PowerPoint 9 has everything you need. Here is an overview map:

Try it (it takes about 2 pages to do 1 S-AES problem) and write back with a specific problem if you get stuck somewhere!

OH! Okay, those are constants. They never change. It's always going to be 80 the first time and 30 the second time. For every single problem :)