# GryphonCTF_2016: pr0_5k473r

Category: Crypto Points: 10 Description:

pr05k473r1337 is so cool! He grinded 5 railings in a row! Creator - Darren Ang (@Southzxc)

## Write-up

We are given a text file. Inside it, we have Gp7nnCm7py0_3cTuym__7f3Fh_u57h_}{d43. To get the flag, you need to take a look at the description and we know that it's 5 railings. Immediately, think of the Railfence cipher. We know it's 5 rows, thus we ge this.

Gp7nnCm7py0_3cTuym__7f3Fh_u57h_}{d43

G       p       7       n       n
C     m 7     p y     0 _     3 c
T   u   y   m   _   _   7   f   3
F h     _ u     5 7     h _     }
{       d       4       3


Therefore, the flag is GCTF{hump7y_dump7y_547_0n_7h3_f3nc3}.