100 points

“The fault, dear Brutus, is not in our stars, but in ourselves.” (I.ii.141) Julius Caesar in William Shakespeare’s Julius Caesar

Cipher Text: 7sj-ighm-742q3w4t

Right off the bat there are a lot of clues to how the flag is encoded. The Caesar quote and challenge name both point to Caesar cipher. Also we know that the flags are in format RC3-2016-xxx, so the first two sections of the encoded flag are likely RC3-2016-.

Let’s try substituting letters and numbers from that section into a simple encoding table:

1
2
0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ
ghij  m      s              7

We can see a pattern developing, so let’s fill out the rest of the table:

1
2
0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ
ghijklmnop qrstuvwxyz0123456789abcdef

We can now decode the flag: RC3-2016-ROMANGOD.