Tags: crypto 

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# Write-up SALAD - RC3 Fall CTF 2016

Challenge text:

“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

This challenge provides a Cipher Text, where every character was rotated by 20 positions using a custom alphabet. The custom alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.
The challenge was solved using caesar.py, created by rickvg, which can be found in this repository.

Usage:
> python caesar.py [integer|all] [input file]

In this case, I removed the dashes (-) from the cipher text as they were not part of the alphabet and used the command:
> python caesar.py all cipher

Output of the script:

>ROT 1: 8TKJHIN853R4X5U

>ROT 2: 9ULKIJO964S5Y6V

>ROT 3: AVMLJKPA75T6Z7W

>ROT 4: BWNMKLQB86U708X

>ROT 5: CXONLMRC97V819Y

>ROT 6: DYPOMNSDA8W92AZ

>ROT 7: EZQPNOTEB9XA3B0

>ROT 8: F0RQOPUFCAYB4C1

>ROT 9: G1SRPQVGDBZC5D2

>ROT 10: H2TSQRWHEC0D6E3

>ROT 11: I3UTRSXIFD1E7F4

>ROT 12: J4VUSTYJGE2F8G5

>ROT 13: K5WVTUZKHF3G9H6

>ROT 14: L6XWUV0LIG4HAI7

>ROT 15: M7YXVW1MJH5IBJ8

>ROT 16: N8ZYWX2NKI6JCK9

>ROT 17: O90ZXY3OLJ7KDLA

>ROT 18: PA10YZ4PMK8LEMB

>ROT 19: QB21Z05QNL9MFNC

>ROT 20: RC32016ROMANGOD

>ROT 21: SD43127SPNBOHPE

>ROT 22: TE54238TQOCPIQF

>ROT 23: UF65349URPDQJRG

>ROT 24: VG7645AVSQERKSH

>ROT 25: WH8756BWTRFSLTI

>ROT 26: XI9867CXUSGTMUJ

>ROT 27: YJA978DYVTHUNVK

>ROT 28: ZKBA89EZWUIVOWL

>ROT 29: 0LCB9AF0XVJWPXM

>ROT 30: 1MDCABG1YWKXQYN

>ROT 31: 2NEDBCH2ZXLYRZO

>ROT 32: 3OFECDI30YMZS0P

>ROT 33: 4PGFDEJ41ZN0T1Q

>ROT 34: 5QHGEFK520O1U2R

>ROT 35: 6RIHFGL631P2V3S

Flag:
> RC3-2016-ROMANGOD

Original writeup (https://github.com/rickvg/RC3-Fall-CTF-2016-write-ups/tree/master/Write-up-Salad).