Campaigns / Proof of Tampering / Affine Witness

Affine Witness

a

Architect

ahonore

Difficulty

2/5

ETA

10 min

A sticky note was found under the archive desk. It contains a short ciphertext and a margin formula. The handwriting matches the person who opened the evidence drawer.

Decrypt the message. The flag is the recovered location in lowercase, with words separated by underscores.

Alphabet: A=0, B=1, ..., Z=25
Encryption: E(x) = (5*x + 8) mod 26

Ciphertext:
QIZPWTFAWVZUAEZR

◆ Input solution

◇ Stage cleared

Next Stage →